Inventor Service Manual

AI
RCONDI
TIONING
SYSTEMS
Model
s:
U-
MATCH I
NVERTER
Ser
viceManual
Ser
viceManual
Ⅰ
ChapterⅠ Introduction to Products
． Kinds of Products
1．
Universal Duct type Floor ceiling Cassette
outdoor unit type type
VDI VKI VCI
URS-09 9K 9K -
URS-12 12K 12K -
URS-18 18K 18K 18K
URS-24 Single 24K 24K 24K
URS-30 phase 30K 30K 30K
URS-36 36K 36K 36K
URS-45 45K 45K 45K
URS-50 50K 50K 50K
URT-36 36K 36K 36K
URT-45 Three 45K 45K 45K
URT-50 phase 50K 50K 50K
URT-60 60K - -
Power supply mode：Single phase 1PH 220－240V ～ 50Hz
Three phase 3PH 380－415V ～ 50Hz
3. Features of Products
Combining the comfort of central air conditioner and easy installation, high flexibility and suchlike
advanges of high-grade small-sized split household air conditioner, INVENTOR duct type air-conditioner
unit features high efficiency, long-distance air supply, high- quality room air, reliable performance, simple
operation, etc. It can be widely used in small supermarket, chain stores, living rooms, hotel, restaurant,
offices, meeting room and villa.
a) Flexible Installation: The user can determine the air supply/return mode, condensate outflow
direction and air vent type according to the needs of installation.
b) High Efficiency and Energy Saving: High-quality compressor is installed. The evaporator
employs hydrophilic aluminum foil and inner threaded copper tube so as to ensure high
efficiency of heat exchange and increased energy-efficiency ratio of the unit.
c) Long-distance Air Supply: For extra residual pressure design, the air can be blown to a long
distance after centralized handling within the indoor unit.
d) High- quality Room Air: The air duct of the unit may be connected to multiple air vents so
that the air-conditioning temperature and humidity within the room will be evenly distributed.
To improve the room air quality, the unit is equipped with highly efficient and healthy filter in
which nanometer photocatalyst or catechin is used as the filtering medium.
e) Reliable Performance: The unit with full functions has powerful self-diagnosis function. (See
the Microcomputer Control System for detailed information).
f) Simple Operation: Simple controller and flexible remote controller enable control of unit as
your desire.
g) Control of Fresh Air: 11 kinds of different fresh air flow volume can be set to adjust it
accurately and reduce power consumption.
h) Lock of Temperature Range: The user can lock the temperature range as desired. This is
suitable for public space.
i) Weekly Timer: It has the function of centralized control and can set startup and stop of the unit
at 4 periods of time of each day in a week.
3.1 Microcomputer Control System SeeTable 1-1
Control Function Protection Function Display Functions

Memory Function High/Low Pressure Protection TIMER On/Off
Remote Control Overload Protection Fan Speed Display
Timer Function Overcurrent Protection Running Mode Display
Diagnosis and Alarm Function Exhaust HighTemperature Protection Defrosting Display
Sleep Function Reverse Phase Protection Test Display
Auto Function Antifreezing Protection Sleeping Display
Anti Cold-air Function High Temperature Protection Temperature Display
Residual Heat Blowing Function Sensor Failure Alarm Failure Code
Control Function to Sub-rooms
Centralized Control Function ★
◇Control Functions:
Memory Function (Upon reset after power failure, the unit will run under its original status without
any change in mode and parameters).
Remote Control (The unit is provided with different controllers for your option. The wired controller
can receive the command from a distance up to 10 meters).
Timer Function (The unit may be set to TIMER On / Off separately or in cycle).
2
Diagnosis and Alarm Function (Upon any failure during operation, the unit will display the failure
code and give out alarm).
Energy Saving Function (The unit can automatically perform cost-effective control under
energy-saving mode).
Auto Function (When the unit is under cooling mode, the indoor fan can automatically adjust its
speed according to the actual needs of the system).
Anti Cold-air Function (Under heating mode, indoor fan will operate till indoor heat exchanger is
over indoor temperature.)
Control Function to Sub-rooms (The startup and stop of the unit can be controlled through control of
switch in any sub-room.)
Residual Heat Blowing Function (Under heating mode, the indoor fan will stop after compressor has
been stopped for a period of time.)
◇ Protection Functions:
High / Low Pressure Protection (If the suction pressure of the compressor is too low and the
exhaust pressure is two high, the compressor will be stopped and the failure code will be displayed).
Overload Protection: (The compressor with self-heat protection will be stopped if its temperature
exceeds the permissible value, and will be started as long as the temperature resumes to normal.
Over-current Protection (When the compressor current exceeds the normal value, the compressor
will be stopped and the failure code will be displayed).
Exhaust High Temperature Protection (When the exhaust temperature of the compressor exceeds
the permissible value, the compressor will be stopped and the failure code will be displayed).
Reverse Phase (Phase Loss) Protection (If the power is inconsistent of phase sequence or phase
loss, the unit will not be started and the failure code will be displayed).
Antifreezing Protection (When the surface temperature of indoor heat exchanger is too low, the
compressor will be stopped and the failure code will be displayed).
High Temperature Protection (When the surface temperature of indoor heat exchanger is too high,
the compressor will be stopped and the failure code will be displayed).
Sensor Fault Alarm (When the sensor is in short circuit or open circuit, the failure code will be
displayed).
◇ Display Function:
CLOCK Display (To display and set the real time).
Timer ON/ OFF Display (To display and set the time for auto start or stop).
3
CANCEL TIMER Display (To display the timer cancellation).
FAN SPEED Display (The fan speed is displayed in HIGH, MEDIUM or LOW).
RUN MODE Display (Cooling, Dehumidify, Heating, Fan)
TEST Display (Display when under test mode).
ENERGY SAVING Display (Display when running under energy saving mode)
TEMPERATURE Display (Display the room temperature and preset temperature)
Failure code Display
★ Weekly Timer and Centralized Control Function

Weekly timer and centralized control function can be set in this unit.A centralized controller with
weekly timer can control on/off and timer of up to 16 units at the same time or of every single main unit to
eliminate the trouble of turning on/off it.The centralized controller of duct type unit communicates with the
manual controller of a single unit through 485 method and the max. distance between them is up to
1200m.It will display serial numbers of the single unit which are decided by location of DIP switch of
manual controller of the single unit.
Loc. No Loc. No Loc. No Loc. No

Weekly Timer Centralized Controller Manual controller Manual controller
Display board Display board
Up to groups
DIP swicth
Location
Tel line base Tel line base Tel line base
Power supply
Max.
Switch power supply
Fig.1-1
Note: Please specified whether need this control function or not before purchase.
4
4 Specifications and Technical Parameters
4.1 Nominal Condition and Working Temp Range Table 4-1

Condition Temp Indoor air temp Outdoor air temp
Nominal 27 DB / 19 WB 35℃ DB / 24℃ WB
Cooling Max. 32℃ DB / 23℃ WB 43℃ DB / 26℃ WB
Min. 18℃ DB / 14℃ WB 18℃ DB / ―
Nominal 20℃ DB / ― 7℃ DB / 6℃ WB
Heating Max. 27℃ DB /18℃ WB 24℃ DB / 18℃ WB
Min. 15℃ DB / ― －7℃DB / -8℃WB
4.2 Specifications and Technical Parameters Table
，URS-12，
4.2.1 URS-09，，URS-18，
，URS-24
URS-09 URS-12 URS-18 URS-24

Model
VDI-09 VDI-12 VDI-18 VDI-24
Items Cooling Heating Cooling Heating Cooling Heating Cooling Heating
Capacity W 2600 2900 3500 3700 5000 5800 7000 8000
Power W 770 970 1080 1220 1750 1850 2450 2600
Current A 6.5 7.0 7.5 8.5 11.5 13.5 17.5 18.7
Power supply 220-240V~ 50Hz
Compressor Hermetic scroll inverter compressor
3
Air flow volume m /h 450 520 840 1400
Indoor dB(A) 40 42 40 44
Noise
Outdoor dB(A) 56 57 56 57
Refrigerant R410A
Charge volume kg 1.0 1.2 1.5 1.8
Connecting Liquid mm ф6 ф6 ф6 ф9.52
pipe Gas mm ф9.52 ф12 ф12 ф16
W mm 995 995 1120 1345
D mm 750 750 795 594
Indoor unit
H mm 258 258 266 268
Weight kg 27 27 36 37
W mm 878 878 878 994
Outdoor D mm 360 360 360 428
unit H mm 610 610 610 750
Weight kg 32 40 40 56
Drainage pipe
mm ф20×1.5 ф20×1.5 ф30×1.4 ф20×1.5
(inside diameter x
5
wall thickness)
4.2.2 ，URS-45，
URS-36，，URS-50
URS-36 URS-45 URS-50
Model
VDI-36 VDI-45 VDI-50
Items Cooling Heating Cooling Heating Cooling Heating
Capacity Capacity 10000 12000 12000 14000 14000 15500
Power Power 3700 3800 5000 4500 6000 5100
Current Current 17.0 17.0 22.9 20.8 27.4 23.3
3
Air flow volume m /h 2000 2000 2400
Indoor dB(A) 50 50 50
Noise
Outdoor dB(A) 62 63 63
Refrigerant R410A
Charge volume kg 4.0 4.0 4.0
Connecting Liquid mm ф12 ф12 ф12
pipe Gas mm ф19 ф19 ф19
W mm 1335 1335 1335
D mm 834 834 834
Indoor unit
H mm 290 290 290
Weight kg 57 57 57
W mm 1110 1110 1110
Outdoor D mm 450 450 450
unit H mm 1385 1385 1385
Weight kg 128 128 128
Drainage pipe mm
(inside diameter x wall ф20×1.5 ф20×1.5 ф20×1.5
thickness)
，URT-45，
4.2.3 URT-36，，URT-50，
，URT-60
URT-36 URT-45 URT-50 URT-60
Model
VDI-36 VDI-45 VDI-50I VDI-60
Capacity W 10000 12000 12000 14000 14000 15500 16000 18000
Power W 3600 4000 5100 4900 6300 5500 6700 5200
Current A 6.5 7.2 8.3 8.2 10.3 9.0 13.0 8.9
Power supply 380-415 ~ 50Hz
6
3
Indoor Noise 50 50 50 53
Noise
Outdoor 62 63 63 64
Refrigerant R410A
Connecting Liquid mm ф12 ф12 ф12 ф12
pipe Gas mm ф19 ф19 ф19 ф22
W mm 1335 1335 1335 1335
D mm 834 834 834 882
Indoor unit
H mm 290 290 290 330
Weight kg 57 57 57 66
W mm 1110 1110 1110 1110
Outdoor D mm 450 450 450 450
unit H mm 1385 1385 1385 1385
Weight kg 128 128 128 138
Drainage pipe mm
(inside diameter x ф20×1.5 ф20×1.5 ф20×1.5 ф32×1.4
wall thickness)
，URS-12，
4.2.4 URS-09，，URS-18，
，URS-24
Model
VKI-09 VKI-12 VKI-18 VKI-26
Capacity Capacity 2600 2900 3500 3900 5000 5500 7000 8000
Power Power 900 1100 1200 1300 2000 2400 2500 2600
Current Current 6.5 7.0 7.5 8.5 11.5 13.5 17.5 18.7
3
Indoor dB(A) 45 46 54 50
Noise
Outdoor dB(A) 55 56 56 59
Refrigerant R410A
Connecting Liquid mm ф6 ф6 ф6 ф9.52
pipe Gas mm ф9.52 ф12 ф12 ф16
W mm 836 836 836 1300
Indoor unit
D mm 695 695 695 600
7
H mm 238 238 238 188
Weight kg 27 27 27 32
W mm 878 878 878 994
Outdoor D mm 360 360 360 428
unit H mm 610 610 610 750
Weight kg 32 40 40 56
Drainage pipe mm
(inside diameter x ф20×1.5 ф20×1.5 ф30×1.4 ф20×1.5
wall thickness)
4.2.5 ，URS-45，
URS-36，，URS-50
Model
VKI-36 VKI-45 VKI-50
Power Power 3700 3800 5000 4500 6000 5100
Current Current 17.0 17.0 22.9 20.8 27.4 23.3
3
Noise
Refrigerant
W mm 1590 1590 1590
D mm 695 695 695
Indoor unit
H mm 228 228 228
Weight kg 42 42 42
W mm 1110 1110 1110
unit H mm 1385 1385 1385
Weight kg 128 128 128
Drainage pipe mm
(inside diameter x wall ф20×1.5 ф20×1.5 ф20×1.5
thickness)
，URT-45，
4.2.6 URT-36，，URT-50
8
URT-36 URT-45 URT-50
Model
VKI-36 VKI-45 VKI-50
Capacity W 10000 12000 12000 14000 14000 15500
Power W 3600 4000 5100 4900 6300 5500
Current A 6.8 8.2 8.3 8.2 10.3 9.0
3
Noise
Refrigerant R410A
W mm 1590 1590 1590
D mm 692 692 692
Indoor unit
H mm 238 238 238
Weight kg 42 42 42
W mm 1110 1110 1110
unit H mm 1385 1385 1385
Weight kg 128 128 128
Drainage pipe mm
(inside diameter x ф20×1.5 ф20×1.5 ф20×1.5
wall thickness)
，URS- 24
4.2.7 URS-18，
Model
VCI-09I VCI-12 VCI-18 VCI-24
Capacity W 5000 5800 7000 8000
Power W 2000 2400 2500 2600
Current A 11.5 13.5 17.5 18.7
3
Air flow volume m /h 680 1180
Indoor Noise 47 47
Noise
Outdoor 56 59
Refrigerant
Charge volume kg 1.5 1.8
9
Connecting Liquid mm ф6 ф9.52
pipe Gas mm ф12 ф16
W mm 660 840
D mm 660 840
Indoor unit
H mm 230 240
Weight kg 20 30
W mm 878 994
Outdoor D mm 360 428
unit H mm 610 750
Weight kg 40 56
Drainage pipe
(inside diameter x ф30×1.4 ф20×1.5
wall thickness)
4.2.8 ，URS-45，
URS-36，，URS-50
Model
VCI-36 VCI-45 VCI-50
Capacity W 10000 12000 12000 14000 14000 15500
Power W 3700 3800 5000 4500 6000 5100
Current A 25.1 26.2 33.3 30.6 28.8 35.5
3
Noise
Refrigerant R410A
W mm 840 840 840
D mm 840 840 840
Indoor unit
H mm 320 320 320
Weight kg 38 38 38
W mm 1110 1110 1110
unit H mm 1385 1385 1385
Weight kg 128 128 128
Drainage pipe mm
ф20×1.5 ф20×1.5 ф20×1.5
(inside diameter x
10
wall thickness)
，URT-45，
4.2.9 URT-36，，URT-50
URT-36 URT-45 URT-50
Model
VCI-36 VCI-50 VCI-50
Power Power 3600 4000 5100 4900 6300 5500
Current Current 8.5 9.5 11.6 11.0 13.8 12.5
3
Air flow volume m /h Air flow volume 1650 1700
Indoor Noise 53 53 53
Noise
Outdoor 62 63 63
Refrigerant R410A
W mm 840 840 840
D mm 840 840 840
Indoor unit
H mm 320 320 320
Weight kg 38 38 38
W mm 1110 1110 1110
unit H mm 1385 1385 1385
Weight kg 128 128 128
Drainage pipe mm
(inside diameter x ф20×1.5 ф20×1.5 ф20×1.5
wall thickness)
Note：
1.The cooling capacity was tested under nominal condition corresponding to the unit external standard residual pressure. The parameters are
subject to that on nameplate.
2.The noise was measured in semi-anechoic room. In actual operation, it may be higher due to change of environment.
11
5. Characteristics Curve
5.1 Relationship between Air-Conditioner Low Pressure and Temperature (Fig. 3-1)
Cooling running: There is the same condition indoors and outdoors.
Heating running: Indoor condition, dry bulb of 21℃, wet bulb of 15.5℃.
7 7
Low低压压力(绝对值)(bar)
pressure (absolute value) (bar)

pressure (absolute value) (bar)
低压压力(绝对值)(bar)
6
5 5
4
4
3
Low 3
2
15 20 25 30 35 2
50 60 70 80(%) 0 5 10 15 20
干球温度(℃)/湿度(%)
Dry bulb temp. (℃)/Humidity (%) 干球温度(℃)/湿度(%)
Dry bulb temp. (℃)/Humidity (%)
(a) Cooling operation (b) Heating operation

Fig.3-1
5.2 Performance Curve（Fig.3-2）
Indoor Relative Humidity (50%)

Outdoor Relative Humidity (50%)
Change of Cooling Capacity (%)
Indoor Wet Bulb (℃)

Change of Heating Capacity (%)
Indoor Wet Bulb (℃)
Outdoor Dry Bulb Temp. (℃) Outdoor Dry Bulb Temp. (℃)
(a) Cooling Characteristics (b) Heating Characteristics

Fig. 3-2
12
5.3 Relationship between Cooling Capacity / Refrigerant Charge and Connection Pipe Length
(Fig. 3-3)
30
20
indoor and outdoor units (m)
90%
92%
室内外机高度差(m)
Liquid pipe diameter (mm)
Refrigerant charge volume (x150g)

10
94%
96%
100%
98%
0
Height difference between
-10
-20
-30
10 20 30 40
连接管长度(m)
Connection pipe length (m) Connection pipe length (m)
(a) Change of cooling capacity with that of connection pipe length (b) Change of refrigerant charge volume with that of connection pipe length
5.4 Relationship between Air Flow and Static Pressure
1800
1600
1400
AIR FLOW(m3/h)
1200
1000
800
600
400
0 20 40 60 80 100 120
EXTERNAL STAIC
PRESSURE(Pa)
(a) URS-24 and VDI-24 URS-24 and VDI-24

(b) URT-36 / URS-36 、VDI-36
13
VDI-45
VDI-50
3000
2800
2600
2400
2200
AIR FLOW(m3/h)
2000
1800
1600
1400
1200
1000
800
600
400
-20 0 20 40 60 80 100 120 140 160 180 200

EXTERNAL STATIC
PRESSURE(Pa)
（a）VDI-60
Fig. 3-4
14
6. Main Parts
6.1 Sketch of Structure of Unit
(a) 09～18kBtu indoor unit (b) 24～60kBtu indoor unit

Fig. 4-1Indoor Unit
Note:
1——Condensate pipe of drainage pump 2——Rectangle air outlet
3——Condensate pipe of water tray 4——Air Inlet
Fig. 4-2 Outdoor Unit
Note: 5——Air inlet 6——Air outlet
15
7. Outline and Installation Dimension
7.1 Outline and Dimension of Indoor Unit (Fig.5.1)
Duct type indoor unit
(a) VDI-09 and VDI-12
(b) VDI-18
16
Air return Air supply
H
J
I
Gas pipe Liquid pipe Drainage pipe Electric box
A
B
F
C
D
E
G
Unit：mm
Drainage pipe (out
Items Liquid Gas
A B C D E F G H I J diameter×wall
Models pipe pipe
thickness)
VDI-24 1063 505 820 1159 1247 504 1088 160 211 268 ф9.52 ф16 ф20×1.5
VDI-36 1011 748 820 1115 1226 744 1047 160 231 290 ф12 ф19 ф20×1.5
ф12 ф19
VDI-45 1011 748 820 1115 1226 744 1047 160 231 290 ф20×1.5
VDI-50 1011 748 820 1115 1226 744 1047 160 231 290 ф12 ф19 ф20×1.5
788 ф12 ф22

VDI-60 1015 784 820 1115 1226 1051 160 258 330 ф32×1.4
（c）Other models
Fig. 5-1 Outline and Dimesion of Indoor Unit
17
Floor ceiling type unit
Model A B C D E
VKI-09
VKI-12 836 238 745 695 260
VKI-18
VKI-24 1300 188 1202 600 260
VKI-36
VKI-45 1500 238 1491 695 260
VKI-45
18
（Fig.5-2）
7.2 Outline and Dimension of Outdoor Unit（）
E
D
A
Unit：mm
URT-36
URS-09 URS-36
Unit URT-45
Model URT-50
URS-18 URS-50
URT-60
A 760 950 950
B 320 412 412
C 530 700 1250
D 540 572 572
E 286 378 378
Fig. 5-2 Outline and Dimesion of Outdoor Unit
19
8. Refrigeration System Principles
Refrigeration Cycle: The low-temperature and low-pressure refrigerant vapour in the evaporator is
compressed into high-temperature and high-pressure gas by the compressor, and then the gas enters
into condenser.The gas becomes high-temperature and high-pressure liquid through heat exchange with
outdoor air, and then the liquid passes through the capillary for cooling and decompression by throttling
and enters into evaporator.After that, the gas-liquid refrigerant in the envopator is completely evaporated
to cool the indoor air.The vapour out of the evaporator is re-compressed by the compressor. So is the
above procedure recycled that the cooled air in the duct is contiuously sent to air-conditioning area with
the help of fan motor.
Heating Cycle: It is reverse to cooling cycle。In this case, 4-way valve will reverse and flow direction of
refrigerant changes, i.e the vapour out of the compressor enters into heat exchanger for condensation.
The refrigerant after condensation passes through the capillary for throttling.After that it evaporates in
the outdoor heat exchanger, at last it will be sucked and compressed by compressor. So is the above
procedure recycled that the hot air in the duct is contiuously sent to air-conditioning area with the help of
fan motor.
Working Principle of the Unit:
Flow direction during cooling
Flow direction during heating

3-way Valve (gas valve)
Indoor Unit Outdoor Unit
Connection pipe
(with insulating tube)
Gas-liquid separator
Comp-
ressor
Flare joint
Main Capillary
Connection pipe
(with insulating tube) 3-way Valve (liquidvalve)
(a) Working principle of cooling only unit
20
Flow direction during cooling
Flow direction during heating
3-way Valve (gas valve)

Indoor Unit 4-way Valve Outdoor Unit
Connection pipe
(with insulating tube)
Gas-liquid separator
Comp-
Flare joint ressor
Main Capillary
Auxiliary Capillary
Filter
Connection pipe One-way Valve

(with insulating tube) 3-way Valve (liquidvalve)
(b) Working principle of heat pump unit
Fig. 6-1
21
Chapter II Control Functions
1. Control Mode
The 4-in-1 DC Inverter Unit consists of outdoor mainboard, indoor mainboard and manual
controller, which are lined via communication wires. In this way, one outdoor unit can be used with
different indoor units of the equal capacity (duct type unit, floor ceiling unit, cassette type unit and
ceiling type unit), and the cooling and heating share one electronic expansion valve.
The outdoor compressor is DC inverter compressor, in which the advanced sine wave control
mode is used, featuring in low vibration, low noise and high efficiency. The single-phase unit also
uses the PFC control, with PFC value up to 0.99 or higher, so the interference to the electric grid
is very low.
The outdoor unit also applies the advanced PI algorithm, able to automatically and quickly adjust
the working frequency of the compressor according to the change of indoor loads. This can not
only meet the user’s requirements for comfort but also save unnecessary electric energies.
This unit can be controlled via LCD controller easily or controlled from remote controller. It can
also be controlled from centralized controller, or put under remote monitor by PC computer.
Besides, it can also be configured with weekly timer wired controller which can automatically
switch on or off the unit at predefined time for each day in a week. This is suitable to family, office,
factory and man-free places.
2 Introduction Control Functions
2.1 Basic Control Functions
2.1.1 Cooling Mode
After setting to cooling mode, the indoor fan will run at preset speed after 3 seconds and the
outdoor unit will start to calculate the system load demand. If the load is “0”, the other loads
except the indoor fan and indoor drainage pump will not be put into operation. If the load is over
“0”, the electronic expansion valve will be firstly opened and then the outdoor fan is started. After
30 seconds, the compressor is started.
Under cooling mode the range of temperature setting is 16℃~30℃ and the initial value is 26℃.
2.1.2 DRY Mode
The DRY mode is basically same as the cooling mode. The difference is that: ①The speed of
indoor fan is fixed at low speed; and ②The maximum value of capacity output is 90%.
Under DRY mode, the range of temperature setting is 16℃~30℃ and the initial value is 24℃.
2.1.3 Heating Mode
After setting to heating mode, the outdoor unit will start to calculate the system load demand. If
the load is “0”, all the other loads will not be put into operation. If the load is over “0”, the electronic
expansion valve will be firstly opened and then the outdoor fan is started. After 30 seconds, the
compressor is started, the 4-way valve is energized and the indoor fan runs under anti cold air
mode.
Under DRY mode, the range of temperature setting is 16℃~30℃ and the initial value is 20℃.
2.1.4 Fan Mode
When the indoor unit is set to fan mode, all the loads of the outdoor unit will be stopped and the
indoor fan will run at preset speed. Under this mode, the fault is detected but will not be treated.
The temperature is not adjustable, displayed at 26℃.
2.1.5 Auto Mode
Under this mode, the run mode will vary with the ambient temperature according to the following
conditions:
When Tamb.＞26℃, the unit will run under cooling mode and the preset temperature is 26℃;
When 20℃≤Tamb.≤26℃, the unit will run under DRY mode and the preset temperature is 24℃;
When Tamb.＜20℃, the unit will run under heating mode and the preset temperature is 20℃. When
Tamb. ≥24℃, the unit will exit the heating mode. For cooling-only unit, when Tamb.＜20℃, the unit
will run under fan mode and the preset temperature is 20℃. When Tamb.≥24℃, the unit will exit the
fan mode.
Once the mode is activated, the unit will run 30 seconds the shortest before it switch the run
status under auto mode according to the ambient temperature.
2.2 Special Control Functions
2.2.1 Energy-saving Function
Set a upper and lower limit of temperature by using manual controller, so that the temperature of
air conditioner is set to an energy-saving range, thus to save the power consumption of the air
conditioner. For example, the temperature under cooling mode is defaulted 16～30℃, but the user
may customize it to 26～30℃ by using manual controller. In this range, the lowest setting is 26℃
other 16℃.
2.2.2 Memory Function
Upon re-energization after power shutdown or failure, the air conditioner can memorize the last
work mode, temperature setting, fan speed and other parameters, so that it is not necessary to
repeat setting of those parameters. The user may also inactivate this function by using manual
controller.
2.2.3 Timer Function
For easy control of the air conditioner, the user may set the air conditioner to timer on or timer off
by using the manual controller. The timer is available with two modes for user’s option, i.e.
countdown and 7-day time section.
2.2.4 Sleep Function
If the user requires air conditioner during sleep, this function may automatically increase or
decrease the preset temperature, so as to meet the users’ needs for comfort and also save the
energy. If used with timer function, the energy saving effect will be better.
2.2.5 Alarm Function
When the air conditioner is abnormal, it can automatically display the fault or protection type,
while triggering the sound and lighting alarm.
2.2.6 Week Timer Centralized Control Function
The user may select centralized controller to control 16 units simultaneously for their start/stop,
timer on/off each day and key shield. The function is powerful, particularly suitable to
long-distance air conditioner system with many units.
2.2.7 Remote Monitor Function
By selecting the remote monitor function, the user may monitor the working parameters and
control the run mode of the air conditioner from a family PC. This is suitable to centralized control
of air conditioners in hotel, restaurants and factory. Up to 254 sets of units may be monitored
simultaneously.
2.2.8 Fresh Air Function (Duct Type Unit)
This function is suitable to duct type unit and helpful to introduce outdoor fresh air and enhance
the user’s comfort during use of the air conditioner. It is a truly air conditioning system.
2.2.9 Drainage Function (Duct Type Unit)
This function is suitable to duct type unit and helpful to extend the applications of the air
conditioner. By this function, the installation of air conditioner will no longer be restricted.
2.2.10 Air Valve Control Function (Duct Type Unit)
This function is suitable to duct type unit. By this function, the unit may be connected to 8 air valve
controllers. The fan speed is controlled by controlling the number of air valves that will be opened
or closed, thus to meet the needs of each room for air flow.
2.3 Protection Function
2.3.1 High Pressure Protection
When high pressure protection is detected, the unit will shut down all the loads (except the 4-way
valve of heating) and shield all the keys and remote signals except the On/Off, in which case the
run indicator will blink (or display fault code E1) and the buzzer will alarm. The fault cannot be
restored automatically. You shall need to press ON/Off to stop the unit, then turn off the indicator
(or clear E1 display) before pressing ON/OFF. The unit will be restarted if the high pressure
protection disappears. Otherwise, the run indicator will blink (or display fault code E1) and the
buzzer will alarm.
2.3.2 Low Pressure Protection
No matter the unit is under ON or standby status, it will be deemed low-pressure protection as
long as it is detected that the low-pressure switch is cut off, in which case the indicator will blink
(or display E3), all the loads will be stopped (except the 4-way valve of heating). If the fault is
eliminated, the compressor will be restarted after 3 minutes. If three low-pressure faults of
compressor are detected successively in 30 minutes from the first detection to the occurrence of
fault, the indicator will blink (or display E3) and the buzzer will alarm. The unit cannot be restored
automatically. You shall need to press ON/Off to stop the unit, then turn off the indicator before
pressing ON/OFF. The unit will be restarted if the high pressure protection disappears. Otherwise,
the run indicator will blink (or display fault code E3) and the buzzer will alarm.
2.3.3 Exhaust Overtemperature Protection
After the compressor is started, if it is detected that the compressor overload switch is cut off, it
will be deemed compressor overload protection. In this case, the indicator will blink (or display
E5), all the loads will be stopped (except the 4-way valve of heating). If the fault is eliminated, the
compressor will be restarted after 3 minutes. If three compressor overload protections are
detected successively in 30 minutes from the first detection to the occurrence of fault, the
compressor cannot be resumed automatically and the buzzer will alarm. You shall need to press
ON/Off to stop the unit and clear the sound alarm before pressing ON/OFF again. The unit will be
restarted if the high pressure protection disappears. Otherwise, the run indicator will blink (or
display fault code E5) and the buzzer will alarm.
2.3.4 Overload Protection
The temperature of outdoor heat exchanger will be detected during cooling and the temperature
of indoor heat exchanger will be detected during heating. When the temperature of heat
exchanger exceeds the normal working temperature permissible to the unit, it may be reduced by
adjusting the compressor frequency or stopping the unit.
2.3.5 Sensor Fault Protection
The unit will perform real-time detection of the indoor room sensor, evaporator sensor, outdoor
ambient sensor, compressor exhaust sensor and condenser sensor are normally connected. If
the controller detects that any sensor is connected abnormal (in open circuit or short circuit), it will
send out fault signal and the fault code will be displayed on indoor panel or lamp panel. Except
that the unit will not be stopped upon the fault of room ambient sensor, the fault of other sensors
will result in stop of the unit.
2.3.6 Anti-freeze Protection
If the temperature of indoor heat exchanger is too low under cooling mode, frost might occur and
thus affect the cooling effect. This unit is provided with antifreeze protection, so that the frost may
be automatically eliminated to ensure the unit is under the best performance.
3. Wired Controller, Remote Controlled and Week Timer Centralized Controller
3.1 User Guideline for Wired Controller
9 10
11
1
12
2
13
3
14
4
5
15
6
16
7
8
17
Fig. 1
Component of Wired Controller
1 TIMER display 10 SLEEP mode display

2 Display of fan speed (AUTO, HI, MED, LOW) 11 MODE Button
3 Display of DEFROST status 12 For increase of temperature setting
4 Display of energy-saving status 13 For decrease of temperature setting
5 Display of temperature setting 14 Fan button
6 Display of ambient temperature 15 SLEEP button
7 Display of fresh air status 16 TIMER button
8 Mode (COOLING, DRY, FAN, HEAT, AUTO) 17 ON/OFF button
9 Display of fault status
1) ON/OFF (Fig. 2)
2) Press ON/OFF button to start the air conditioner.
3) Press ON/OFF button again to stop the air
conditioner.
Fig. 2
2) Fan control (Fig. 3) (Shown in the figure is relevant
area of display. Same as below).
 With each press of FAN button, the fan speed will

change in a sequence as below:
→ LOW→MED→HI→AUTO→
 Under DRY mode, the fan speed will be

automatically set to LOW.
Fig. 3
3) Temperature adjustment (Fig. 4)
 Press the temperature adjustment key.
▲:For increasing temperature setting;
▼:For decreasing temperature setting

(Each press of this key will increase or decrease the
temperature by 1℃).
Note: Key Lock Function: If you hold down both ▲ and
▼ for 5 seconds, “EE” will be displayed at the position
of temperature setting and all the keys will be locked. If
you hold down both ▲ and ▼ for 5 seconds again, the
key lock function will be deactivated.
When the remote monitor or centralized controller
Fig. 4
shields the display, the key of the display and the
signal of remote controller will be shielded also. In
this case, “CC” will be displayed at position of
temperature setting
 The range of temperature setting under different
modes is :
Heat -------- 16℃～30℃
Cool -------- 16℃～30℃
DRY -------- 16℃～30℃
Fan -------- Temperature setting deactivated
Auto Mode --------------16℃～30℃
4) SLEEP setting (Fig. 5)
 If the controller is under Cooling or DRY mode, the
temperature setting will increase by 1℃ one hour after
pressing SLEEP key and by another 1℃ after 2 hours.
Then, the unit will run at this temperature.
 If the controller is under heating mode, the
temperature setting will decrease by 1℃ one hour after
pressing SLEEP key and by another 1℃ after 2 hours.
Then, the unit will run at this temperature.
 There is no SLEEP function under FAN mode.
Fig. 5
5) Run Mode Setting (Fig. 6)
 With each press of this key, the run mode will
change in the following sequence:
→ COOL→DRY→FAN→HEAT→AUTO
 Under “COOL” mode, the COOL display will be

light up, and the temperature setting must be lower
than the room temperature. If the setting
temperature is higher than the room temperature,
the unit will not run at COOL mode.
 At “DRY” mode, the DRY display will be light up.
Fan motor will run at low fan speed in a specific
temperature range. The dehumidifying effect under
this mode is better than that under COOL mode
and it is more energy saving.
 At “HEAT” mode, the HEAT display will
be light up. The temperature setting must be higher
Fig. 6
than the room temperature. If the temperature
setting is lower than the room temperature, the
HEAT mode operation will not be activated.
 At FAN mode, the fan display will light up. The unit
will automatically adjust the run mode according to
ambient temperature.
 The auto mode is shielded after setting to
energy-saving mode.
Under HEAT Mode, frost will occur on the outdoor unit if
the outdoor temperature is low and humidity is high. This
will result in reduced heat efficiency. in this case, the
controller will automatically activate the defrost function
and the DEFROST will appear.
Note: There is no HEAT mode for cooling-only unit.
6) Timer Setting (Fig. 7)

You may set the auto start time under OFF status and
set auto stop time under ON status. After pressing
TIMER key, the unit will be under timer setting status
and the TIMER will blink. In this case, the user may
press “▲” or “▼” to increase or decrease the time.
Press the TIMER again to validate the timer, so that the
unit will start to count the time. When the unit is under
timer status, you may press TIMER to cancel the timer.
Range of setting: 0.5 ~ 24 hours
Fig. 7
7) Setting of Fresh Air Valve (Fig. 8)
Under stop status, you may hold down FAN SPEED
key for 5 seconds to call out the fresh air setting.
In this case, the FRESH AIR will blink on LCD, and the
exiting fresh air mode will be displayed in temperature
setting area. The user may press “▲” or “▼” to adjust
the fresh air mode. The number definition is as follows:
00――Always under closed statue
01――The fresh air valve will open for 6 minutes if the
unit is started 60 minutes continuously.
unit is started 60 minutes continuously. Fig. 8
10―Fully open
Press ON/OFF to confirm after adjusting the fresh air
mode, so that the system will store this number. After
that, the unit will run per this fresh air mode. The
factory default value is “0” and the fresh air valve is
closed. If starting the unit in this case, there will be no
display of FRESH AIR on LCD.
If the user has set the fresh air mode (1-10), the
FRESH AIR will always appear on LCD as long as the
unit is running, regardless of the system run mode.
The data of fresh air setting will not be cleared upon
re-energization after de-energization.
8) Energy-saving Setting (Fig. 9)

Under stop status, hold down FAN SPEED + “▼” key
simultaneously for 5 seconds to call out the
energy-save setting menu. In this case, the “ENERGY
SAVING SETTING” “COOLING” will appear, (For the
first setting, the initial value 26℃ is displayed), the lower
limit temperature will be displayed in the temperature
setting area and the temperature being set will be
displayed by flash., Use “▲” and “▼” to set the lower
limit of the cooling temperature (range: 16 – 30) and
press ON/OFF to confirm. Use “▲” and “▼” to set the
upper limit of cooling temperature ad display at position
of ambient temperature (range of setting: 16 – 30).
Press ON/OFF to confirm. Fig. 9
Take care that the upper limit temperature shall not be
lower than the lower limit temperature. If the upper limit
temperature shall not be lower than the lower limit
temperature, the system will default the higher as the
upper limit and the smaller as the lower limit. Press
MODE to complete the energy-saving setting under
cooling and dehumidify mode and switch to
energy-saving setting under heating mode (This
function unavailable for cooling-only unit). In this case,
ENERGY SAVING SETTING and HEAT will be
displayed. After completing the setting, hold FAN
SPEED + “▼” key for 5 seconds again to exit the
energy-saving setting. After calling out the
energy-saving setting interface, if there is no operation
within 10 seconds after the system has responded to
the last press, the system will pop up this menu and
display the normal stop interface.
After completing the above setting, the
ENERGY-SAVING will appear on LCD upon next start
of the system. No matter the user operates the unit via
displayer or from remote controller, the temperature
setting shall not exceed the range of energy-saving
setting. For example in Fig. 9, if we set the lower limit of
cooling temperature to 23℃ and the upper limit to 27℃,
the user can only set the cooling temperature between
23℃ and 27℃ by using remote controller and pressing
from display.
If the upper limit temperature is same as the lower limit
temperature, the system can only run at this
temperature under corresponding mode.
After the energy-saving mode is activated, you may
hold FAN SPEED + “▼” key for 5 seconds under stop
status to deactivate the energy-saving setting, but the
value you have set before cannot be cleared and it will
be used as the initial temperature for the next
energy-saving setting.
After a power failure, the energy-saving setting will be
memorized and it will still play the function upon next
energization.
After setting the energy-saving mode, the sleep mode
and auto mode will be shielded.

9) Display of Outdoor Environment Temp. (Fig. 10)
Under normal condition, only the indoor room temp. is
displayed in Environment space. Under start or stop
status, you may hold SLEEP for 5 seconds to display
Outdoor Environment on LCD.
① If the outdoor environment temperature is positive,
there will be no display in temperature space. The
outdoor environment temperature detected inside
the system will be displayed in the space where the
original environment temperature is displayed.
② If the outdoor environment temperature is negative,
the “-“ will be displayed on the next digit of
temperature space. The outdoor environment
temperature detected inside the system will be Fig. 10
displayed in the space where the original
environment temperature is displayed.
10 seconds after display of outdoor environment

temperature, the system will return back to the indoor
environment temperature display interface.
Note: This function is not available if the unit is not
connected with outdoor environment temp. sensor.
10) Memory Function Setting (Fig. 11)

Under stop status, you may hold MODE for 10 seconds
to switch on or off the memory function. The 01
displayed in temperature setting area indicates that the
unit will memorize the start / stop status after
energization and the “02” indicates that the unit will not
memorize the start / stop status after energization.
Press ON/OFF to exit the setting. After calling out the
memory function, if there is no operation within 20
seconds after the system has responded to the last
press, the system will pop up this menu and display the
normal stop interface. The setting of memory function
is still stored.
Fig. 11
11) Debugging Function (Fig. 12)

Under stop status, hold down FAN SPEED + SLEEP
key for 10 seconds to call out the test menu. In this
case, the DEBUG will be displayed. Use MODE key to
adjust the setting and use “▲” or “▼” to set the value.
a）Setting of environment temp. sensor

Under debugging status, use MODE key to adjust the
temperature setting area (on the left side of DEBUG) to
“01”. The setting status is displayed in environment
temperature area (on the right side of DEBUG). Use
“▲” or “▼” to adjust. Three options are available:
① The indoor environment temperature is the
environment temp. at air intake. (01 displayed
Fig. 12
in environment temp area).
② The indoor environment temperature is the
temp. at display (02 displayed in environment
temp area)
③ Air intake temp. sensor is selected for cooling,
dehumidify and air outlet. And manual
controller temp. sensor is selected for cooling
and auto mode (03 displayed in environment
temp area)
The factory default is ③.
After calling out this interface, if there is no
operation within 20 seconds after the system has
responded to the last press, the system will pop up
this menu and display the normal stop interface.
The current setting data will still be stored.
12) View of System Internal Parameters (Fig. 13 and
14)
Under start status, hold down FAN SPEED + SLEEP
key for 10 seconds to call out the test menu. In this
case, the TEST will be displayed. Use “▲” or “▼” to
adjust the display. The definition of 4 numerical tubes
is: The first digit on the uppermost displays the system
number 1 or 2, and the other three digits display the
absolute value of exhaust temp. What is displayed in
temperature setting area (on the left side of TEST) is
the indoor tube temp. and what is displayed in the
Fig. 13
environment temp. area (on the right side of TEST) is
the defrost sensor temp. If the temperature is less than
0, the ℃ will be displayed behind to identify the
difference.
Use “▲” or “▼” to adjust the display. When the first

digit on the uppermost displays the character similar to
“d” (Fig. 14), the 2nd numerical tube displays if the fresh
air valve is open, the 3rd numerical tube displays the
total number of fresh air valve and the 4th numerical
tube displays the number of the air valves opened.
If not released after calling out the parameter test
Fig. 14
interface, the display will return to this interface after 30
seconds and show the normal startup interface.
13) Fault Display (Fig. 15)

When fault occurs during system operation, the
ERROR will flash on the display and the error code will
be displayed as well. For multiple faults, the error
codes will be displayed in cycle. The 1st digit indicates
the system number. The system number will not be
displayed if there is only one system. The last two
digits indicate the error code. For example, what is
shown on right indicates the compressor low pressure
protection in system 1.
Fig.15
3.2 User Guideline for Remote Controller
Names and Functions of Remote Controller Keys
Precautions:
 This remote controller is a general-purpose remote controller, which can be used in
various types (functions) air conditioner. The keys not applicable to this air conditioner
are not explained here.
 Ensure there is no obstacle between the remote controller and the signal receiving
window of the air conditioner.
 The distance able to receive the signal of the remote controller can be as far as 8
meters.
 Never drop or throw at will the remote controller.
 Never let any liquid enter the remote controller. Avoid direct sunshine over the remote
controller. Do not place the remote controller in an extremely hot place.
Fig. 14 Remote Controller

Cooling Mode Operation
Connect the unit to power supply. Press the “ON/OFF”key. Press the “MODE” key to select
“Cooling” mode. Use the “Temperature” key to adjust the set temperature for the room. Refer to
Figure 15.
Heating Mode Operation
Connect the unit to power supply. Press the “ON/OFF”key. Press the “MODE” key to select
“Heating” mode. Use the “Temperature” key to adjust the set temperature for the room. Refer to
Figure 16.
Under the heating mode, the unit has the functions of preventing cold air supply and supplying
remaining heat. After the startup of the compressor, the indoor fan shall start operation when the
evaporator temperature is larger or equals 35℃ or after the unit has be started for 45 seconds, so
as to avoid supply of cold air shortly after the unit is started. After the stop of the compressor, the
indoor fan shall stop operation after supplying air for 120 seconds.
DRY (Dehumidifying) Mode Operations
Connect the unit to power supply. Press the “ON/OFF” key. Press the “MODE” key to select “DRY
(Dehumidifying)” mode. Use the “Temperature” key to adjust the set temperature for the room.
Refer to Figure 17.
Swing Fan Speed Swing Fan Speed
Swing Swing
Auto Auto
o o
22 C 22 C
Model ON/OFF Model ON/OFF
Swing Fan Speed

Swing Fan Speed
Swing
Auto Swing
o Auto
22 C o
22 C
Model ON/OFF
Model ON/OFF
Fan Mode Operation

Connect the unit to power supply. Press the “ON/OFF”key. Press the “MODE” key to select “FAN”
mode. The unit shall operate under “FAN” mode. Press the “FAN” key to select from high, medium
and low speed. Refer to Figure 18.
2 Load two “AAA” batteries (Accessories).
 After batteries are installed, the display

shall display icons and letter codes of all
functions.
 The life of batteries is about 1 year.
1 Open the cover.
 Do not mix new and old batteries or mix
2 Close the cover.
different types of batteries in usage.
 If the remote controller shall not be used for
a long time, take out the batteries to avoid
Figure 19 Replacing Batteries for Remote liquid leakage and any subsequent failure.
Loading Batteries Into Remote Controller

Refer to Figure 19 for the methods and steps of installing batteries into the remote controller.
3.3 Week Timing Controller

1. Week Timing Controller (With Centralized Control Function)
Centralized Control and Week Timer Functions: The centralized controller and the weekly timer
are integrated in the same wire controller. The system has both the centralized control and the
week timing functions. Up to 16 sets of units can be controlled simultaneously by the centralized
controller (weekly timer). The weekly timer has the function of invalidating the lower unit. The
weekly timing function is able to realized four timing ON/OFF periods for any unit every day, so as
to achieve fully automatic operation. No timing control can be set for holidays.
Fig.20
This WEEKLY TIMER adopts 485 mode to communicate with manual control of every duct type
unit, and it can control up to 16 units. Adopting 2-core twisted-pair wire, the longest
communication distance of this TIMER is 1200m. After connected to power, the WEEKLY TIMER
can display all connected units (sequence of unit is determined by code switch of manual control
of every duct type unit). On and off of every duct type unit can be done through the Timer On / Off
of this WEEKLY TIMER, and the button shield operation of manual control can be done through
shield setting on WEEKLY TIMER. Mode selection and temperature adjustment and other
operations are done through the manual control at every unit.
1. Press ▲ or ▼ to select the unit that needed to be control. It is available to control several
units by Group Control (1~16), or control single unit by Single Control.
1. When selected a certain or several units by Single Control or Group Control, Timer setting
and On/off setting can be set. Timer setting can set 4 on/off times in a day in one week; and
on/off setting can be done by pressing on/off button.
2. Connection between WEEKLY TIMER and manual control is shown as following:
Note: Fig.21
1． For upper unit checks 16 lower units consecutively, there will be no more than 16 seconds delay when
setting works till unit responds.
2 Please let us know your requirement before your placing the order, for this WEEKLY TIMER will only be
prepared when customer orders (communication joint with WEEKLY TIMER on manual control had been
prepared).
Chapter III Installation and Test (HV)
Chapter IV Repair and Maintenance

1. List of Error Codes
Table1 Definition of Error Codes on Display Panel

Error code Malfunction
E0 Water pump malfunction
E1 High pressure protection of compressor
E2 Indoor anti-frozen protection
E3 Low pressure protection of compressor
E4 Air discharge high-temperature protection of compressor
E5 Overload protection of compressor or Inverter error
E6 Transmit malfunction
E8 Indoor fan protection
E9 Water flow protection
F0 Malfunction of indoor environment sensor at air return vent
F1 Evaporator sensor malfunction
F2 Condenser sensor malfunction
F3 Outdoor environment sensor malfunction
F4 Malfunction of air discharge sensor
F5 Malfunction of environment sensor on displayer
EH Auxiliary electric heater malfunction
Table 2 LED Indication Codes of Outdoor Main Control Board
Item Display
LED Indication of Outdoor Main Control Board
Indication
LED6 LED5 LED4 LED3 LED2 LED1
DC bus overvoltage protection ON BLINK ON ON ON ON E5
Radiator fin overheat protection ON BLINK ON ON ON BLINK E5
Current sensor fault ON BLINK ON ON BLINK ON E5
Radiator sensor fault ON BLINK ON BLINK ON ON E5
Compressor current protection ON BLINK ON BLINK ON BLINK E5
DC bus undervoltage protection ON BLINK ON BLINK BLINK ON E5
Compressor startup failure ON BLINK OFF ON ON ON E5
PFC abnormal ON BLINK OFF ON ON OFF E5
Compressor clogged ON BLINK OFF ON ON BLINK E5
IPM module resetting ON BLINK OFF ON OFF ON E5
Loss-of-synchronization of compressor motor ON BLINK OFF ON OFF OFF E5
Inverter phase-failure or loss-of-regulation ON BLINK OFF ON OFF BLINK E5
Communication fault from inverter to main
controller ON ON OFF OFF OFF BLINK E5
IPM module protection ON BLINK BLINK ON ON ON E5
Compressor overspeed ON BLINK BLINK ON ON OFF E5
Sensor connection protection ON BLINK BLINK ON ON BLINK E5
Temperature shift protection ON BLINK BLINK ON OFF ON E5
AC contactor protection ON BLINK BLINK ON OFF OFF E5
AC current protection (input side) ON BLINK ON BLINK ON OFF E5
Inverter ambient sensor fault ON BLINK ON BLINK OFF ON E5
High pressure protection ON BLINK OFF OFF OFF BLINK E1
Low pressure protection ON BLINK OFF OFF BLINK OFF E3
Exhaust protection ON BLINK OFF OFF BLINK BLINK E4
Overload protection of compressor ON BLINK OFF BLINK OFF OFF E5
Communication fault (indoor / outdoor unit,
manual controller) ON BLINK OFF BLINK BLINK OFF E6
Outdoor ambient sensor fault ON BLINK BLINK OFF OFF OFF F3
Outdoor coil middle sensor fault ON BLINK BLINK OFF BLINK OFF F2
Inverter exhaust temp. fault ON BLINK BLINK BLINK OFF BLINK F4
Defrost (not fault) ON BLINK OFF BLINK BLINK BLINK Defrost
Oil return (not fault) ON BLINK BLINK BLINK ON BLINK No display
Indoor and outdoor unit incompatible ON BLINK OFF BLINK ON BLINK No display
Note: No indicator LED6 for URS-09, URS-12 and URS-18.
2 . Troubleshooting for Typical Faults

Troubleshooting sequence: Firstly, view the error description according to the error code on the
display. If E5 is displayed, it is needed to open the electric box of outdoor unit and record the LED
indication on the outdoor main control board. Then, find out the fault by referring to the LED
Indication Codes of Outdoor Main Control Board. After confirming the fault, find the cause
according to the instructions below:
A. Communication Fault (E6)
Check the communication wire between indoor unit and outdoor unit to ensure if the wire is
open circuited or short circuited and if the connector is loose.
B. Temperature Sensor Fault (F0, F1, F2, F3, F4 and F5)
Check if the wire from temperature sensor to mainboard is loose. Insert tightly if loose. If the
temperature sensor does not loosen from the mainboard, pull off the temperature sensor and
use multimeter to measure the resistance on the two ends of temperature sensor. If the
resistance is infinite high or very low (close to “0”), we can judge that the sensor is damaged
and shall be replaced. For the position of each temperature sensor on mainboard, please see
the PBC interface diagram attached.
C. High Pressure Protection
When high pressure protection is detected for 3 seconds successively, the unit will shut down
all the loads (except the 4-way valve of heating) and shield all the keys and remote signals
except the On/Off, in which case the run indicator will blink (or display fault code E1) and the
buzzer will alarm. The fault cannot be restored automatically. You shall need to press ON/Off
to stop the unit, then turn off the indicator (or clear E1 display) before pressing ON/OFF. The
unit will be restarted if the high pressure protection disappears. Otherwise, the run indicator
will blink (or display fault code E1) and the buzzer will alarm.
D. Low Pressure Protection
It will be deemed low-pressure protection as long as it is detected for 30 seconds
successively that the low-pressure switch is cut off, in which case the indicator will blink (or
display E3), all the loads will be stopped (except the 4-way valve of heating). If the fault is
eliminated, the compressor will be restarted after 3 minutes. If three low-pressure faults of
compressor are detected successively in 30 minutes from the first detection to the occurrence
of fault, the indicator will blink (or display E3) and the buzzer will alarm. The unit cannot be
restored automatically. You shall need to press ON/Off to stop the unit, then turn off the
indicator before pressing ON/OFF. The unit will be restarted if the high pressure protection
disappears. Otherwise, the run indicator will blink (or display fault code E3) and the buzzer
will alarm.
E. Exhaust Overtemperature Protection
After the compressor is started, it is detected for 30 seconds successively that the exhaust
temperature is higher than 115℃; E4 is displayed; and all the loads will be stopped (except the
4-way valve of heating). After the compressor is stopped for 3 minutes, the fault code will be
cleared and the complete unit will resume to operation if the exhaust temperature is lower
than 90℃. If such protection occurs three time successively within 30 minutes, the complete
unit cannot resume to operation, in which case E4 will be displayed and the buzzer will alarm.
You shall need to press ON/Off to stop the unit and then press ON/OFF again. If the exhaust
temperature is lower than 90℃, the unit will run under preset mode.
F. Communication Fault between Main Controller and Inverter
Check if the communication wire between main control board and inverter is loose or broken.
G. E5 Protection (Overcurrent Protection or Inverter Fault)
Firstly, please check if the overload switch of the compressor is open. If it is not open or the
compressor has no overload switch, please refer to the troubleshooting process for inverter.
3. Inverter Troubleshooting
3.1 Typical Troubleshooting for Inverter URS-09, URS-12 and URS-18
3.1.1 Troubleshooting and Treatment of Inverter Faults
(1) DC Overvoltage: If it is detected that the DV voltage is higher than 420V upon energization,
this fault will be alarmed. It is non-restorable if this protection occurs six times successively in
1 hour. In this case, you must de-energize, discharge completely and re-energize before you
can eliminate this fault.
(2) DC Undervoltage: If it is detected that the DV voltage is lower than 200V upon energization,
(3) Inverter Module Resetting: Initialize the inverter program. This fault is alarmed upon
energization after each de-energization or upon resetting of inverter chip caused by some
interference. 5s will be displayed after occurrence of this fault. Note: It is normal that this
alarm will occur upon energization after de-energization.
(4) Inverter IPM Abnormal: This fault is alarmed when it is detected that IMP module or PFC
module is abnormal. It is non-restorable if this protection occurs six times successively in 1
hour. In this case, you must de-energize, discharge completely and re-energize before you
(5) Radiator Fin Overheat Protection: This fault is alarmed when it is detected in 1s successively
that the radiator fin temperature is higher than 105℃. It is non-restorable if this protection
occurs six times successively in 1 hour. In this case, you must de-energize, discharge
completely and re-energize before you can eliminate this fault.
(6) Compressor Overcurrent Protection: This fault is alarmed when it is detected in 1ms
successively that the transient current of compressor is higher than 18A. It is non-restorable if
this protection occurs six times successively in 1 hour. In this case, you must de-energize,
discharge completely and re-energize before you can eliminate this fault.
(7) Compressor in Loss of Synchronization: This fault is alarmed when it is detected in 2s
successively that the negative potential of the compressor in run period is lower than 20V. It is
non-restorable if this protection occurs six times successively in 1 hour. In this case, you must
de-energize, discharge completely and re-energize before you can eliminate this fault.
(8) Compressor Over-frequency Protection: This fault is alarmed when it is detected in 2s
successively that the working frequency of compressor is higher than 200HZ or the difference
between working frequency and preset frequency is over 40Hz. It is non-restorable if this
protection occurs six times successively in 1 hour. In this case, you must de-energize,
(9) Communication Fault between Inverter and Main Controller: This fault is alarmed when it is
detected in 60s successively that it cannot communicate with the main controller normally.
This fault can be restored automatically.
(10) Current Detection Circuit Fault: This fault is alarmed when it is detected that the average bias
voltage is higher than 12.5% of 1.65V. It is non-restorable if this protection occurs six times
successively in 1 hour. In this case, you must de-energize, discharge completely and
re-energize before you can eliminate this fault.
3.1.2 Troubleshooting for Typical Inverter Faults

3.1.2.1 Switch Power Module is damaged.
The reasons that might cause damage to switch power module include:
● Input DC voltage is too high, over 430V
● High-frequency transformer is damaged.
● The IC card for switch power control is damaged.
● The loads short circuit the 12V indicator.
12V indicator LED8 (h – red ) does not light up or
flash, and the manual controller displays E6.
Yes Check if the HV indicator No

LED10 (red) on mainboard is
bright?
1.Cut off the power and check if the

power cable is correctly connected. If
not, connect it again.
Yes Use multimeter to Yes 2.Make sure if the input power cable is
measure if the DC bus correctly connected. Use multimeter to
voltage is higher than measure if there is voltage between
430V? copper insert X1 and X2 on the
mainboard.
3.if there is voltage between copper
The following may cause 1.Cut off the power insert X1 and X2 on the mainboard.,
that the power supply cannot and check if the input cut off the power and measure if the
be switched on or off supply is within 220V fuse FU1 is damaged. If damaged,
normally: +/-10%. If not, adjust replace the fuse.
1.The high-frequency the power supply. 4.Is the problem solved after replacing
transformer is damaged. 2.If the input is within the fuse and re-energizing? If the
2.The IC card for power mainboard still has no power and the
normal range, the HV and LV indicator remains black, it
control is damaged.
3.The load end is short PFC module might be might be that problem that the PFC
circuited. damaged. In this case, module is damaged. In this case, it is
Solve by replacing the it is needed to replace needed to replace the mainboard.
mainboard. the mainboard.
Eliminate the
fault and make
records.
3.1.2.1 Troubleshooting Process for Switch Power Supply Fault
3.1.2.2 IPM Module Protection
The possible reasons causing inverter IPM protection include:
 The screws fixing the IPM module or PFC module is not properly tightened.
 The IPM module or PFC module is damaged.
 The IPM module or PFC module is in poor radiation.
 The compressor is abnormal or the compressor wiring is wrong.
 The current test resistor R30, R31 or R44 is damaged.
 Interference.
Manual
controller
displays E5
(overcurrent
protection)
Mainboard indicators
Monitor display (LED1~LED5)
IPM ON, ON, ON,

Protection OFF, OFF
Cut off the power. After Wrong judgment caused by

the HV indicator LED10 No interference. Please check if
(red) on mainboard is there is source of interference
black, reenergize and
switch on the unit to run nearby or if the wiring inside
for a period of time. the electric box is correct.
Check if the fault
reoccurs.
Yes
Yes Does the compressor

No
get started to run?
Yes Use multimeter to

measure if the output
voltage 15V of power
Use monitor software to judge if source is normal?
No
the bus voltage is normal? (If Yes
No the working frequency is lower
than 35Hz, the bus voltage is
input voltage multiplying 1.414.
If over 35Hz, the bus voltage
shall be 380V+/-10V). Cut off the power. After the HV indicator is off, check
by steps:
1. Refer to the wiring diagram and check if the wiring
on U, V and W phase of the compressor is correct.
2. Measure if the IPM module is damaged. Method:
1) Check if the screw fixing PFC module is properly
Remove the UVW wiring of the compressor and
tightened. If not, it might result in module
overtemperature or IPM protection. use multimeter to measure the resistance U-N,
2) If the above problems have been eliminated, check V-N, W-N, P-U, P-V and P-W on inverter. It is
if the outdoor unit is well ventilated. If the outdoor normal if the resistance is over 1MΩ; otherwise
temp. is too high under cooling mode, it may cause the module is damaged and it is needed to replace
poor radiation of PFC module and will further result the inverter.
in IPM protection. 3. If the test in Step 1 shows that the IPM module is
3) Check if the radiator is dirty or blocked. If dirty or normal, check the inverter and test the resistor
blocked, it may cause protection due to poor RS30, R31 or R44 for any damage, e.g. broken
radiation of the module. pin or burnt mark. If any, replace the inverter.
4) Measure if 15V power source is normal. If not, the 4. Check if the screws fixing the PFC module are
power supply module is abnormal, in which case the properly tightened. If not, it may cause
mainboard shall be replaced. overheating of module or IPM protection.
5. If the above problems have been eliminated,
check if the outdoor unit is well ventilated. If the
outdoor temp. is too high under cooling mode, it
may cause poor radiation of PFC module and will
further result in IPM protection.
6. Check if the radiator is dirty or blocked. If dirty or
blocked, it may cause protection due to poor
radiation of the module.
Finish the check and connect the wire properly.
Re-energize the unit to start it again.
No Check if the
If the fault is eliminated? compressor is
normal.
Yes
Make records
correctly and report.
3.1.2.2 Troubleshooting Process for IPM Protection

3.1.2.3 Troubleshooting Process for Tripping
Tripping
If the switch
capacity meets
the requirement
Install electric switch

according to the
Tripping occurs Tripping occurs No capacity required in
upon after start of the instruction manual.
energization? compressor?
The leakage current is

too high. Please check
Yes for moisture or replace
the filter.
Check the PFC
function module. Cut Yes
off the power. After
No
PFC is on?
the HV indicator is off,
remove the wiring on
PFC module and use
multimeter to measure
the P-N, P-R, P-S,
R-N or S-N on PFC Check the PFC function
module for short The leakage module. Cut off the
circuit. current is too high. power. After the HV
Please replace the indicator is off, remove
filter. the wiring on PFC
module and use
multimeter to measure
Yes No the P-N, P-U, P-V, P-W,
U-N, V-N or W-N on
Short circuit? inverter for short circuit.
PFC function module is damaged and it

is needed to replace the mainboard.
The possible reasons include: Yes The relay RLY1 No
1. The screw fixing the module is not controlling PTC Short circuit?
tightened. resistor is
2. The relay controlling PTC resistor is
damaged, so that the transient damaged?
surge current upon energization is
too high.
3. The input voltage is too low.
Yes
4. The wiring is wrong.
IPM Module is
damaged and it is
needed to replace the
mainboard. The
PFC inductance No possible causes
insulation is include:
damaged? ① The screw fixing
the module is not
tightened; ②
Severely overloaded;
Yes ③Interference causes
short circuit inside IPM
module.
Relay is damaged; The system is

replace the Replace PFC Check if the wiring abnormal: Please
mainboard. inductance is wrong. check if the wiring or
winding of the
compressor is short
circuited or incurred
to other faults.
Make records
3.1.2.3 Troubleshooting Process for Tripping Protection

3.1.2.4 Troubleshooting Process for Radiator Overheating Protection
E5
主板指示灯 indicators
Mainboard
Monitor监控显示
display （LED1~LED5）
(LED1~LED5)
Radiator overheat Blink, ON, ON,

散热器过热保护
protection 闪亮亮亮闪亮
ON, Blink, ON
If the air outlet and air

If 室外机散热是否良
the outdoor radiator is 如果室外机出风和
intake of the outdoor unit
in good condition? is回风短路，会使散
short circuited, it may
好？ cause poor performance
热器散热效果变差
of the radiator.
If如果散热器脏堵，
the radiator is dirty or
If the radiator is dirty blocked, the radiation
散热器是否脏堵？会使散热器散热效
or blocked? effect will become poor.
果变差
If the IPM
IPM模块和 If如果IPM模块或PFC
the IPM or PFC
module and module is not correctly
模块不打紧，会使
PFC
PFC模块是 module tightened, it may cause
are correctly 模块温度过高，甚
overheating of module or
否打紧？
tightened?
至烧毁模块
even burn.
If the silicate gel is not evenly

If the silicate gel is coated, it will cause poor radiation
如果硅胶涂覆不均，会使模块
evenly coated on IPM
IPM模块或者PFC模 of the module, or wrong judgment
module or PFC 散热不良，或者温度分布不均
due to uneven distribution of
块硅胶是否涂覆均
module? 误判断，或者传感器检测不到
temperature, burn of module as
匀？ the sensor cannot detect regional
某些局部温度过高而烧毁模块
overheating.
If如果散热硅胶涂覆
the silicate gel is
If the silicate gel on IPM coated too thick, it will
IPM模块好PFC模块
module or PFC module 太厚，也会影响散
meets the also affect the radiation
热效果，甚至烧毁
硅胶是否满足要求？ effect or even burn the
requirements? 模块
module.
请检查感温包是否失
Please check if the
temperature
效，或者重新安装模块 sensor
fails, or reinstall the
并打紧
module and tighten it.
Make records
如实记录并反馈
3.1.2.4 Troubleshooting Process for Tripping Protection

3.2 Typical Troubleshooting for Inverter URS-24
1) DC Overvoltage: If it is detected that the DV voltage is higher than 420V upon energization,
2) DC Undervoltage: If it is detected that the DV voltage is lower than 200V upon energization,
3) PFC Abnormal: This fault is alarmed when it is detected that PFC module is abnormal 10
seconds after start of PFC. It is non-restorable if this protection occurs six times successively
in 1 hour. In this case, you must de-energize, discharge completely and re-energize before
you can eliminate this fault.
4) Inverter Module Resetting: The protection when it is detected of the change of compressor
parameters in inverter chip. This protection can be restored automatically.
5) Inverter IPM Protection: The protection when it is detected that the IPM module is abnormal.
It is non-restorable if this protection occurs six times successively in 1 hour. In this case, you
must de-energize, discharge completely and re-energize before you can eliminate this fault.
6) Startup Failure: The protection that the compressor cannot be started normally. It is
non-restorable if this protection occurs six times successively in 1 hour. In this case, you
7) Radiator Sensor Abnormal: The protection when it is detected that the sensor on top of IPM
sensor is open circuit or short circuit. It is non-restorable if this protection occurs six times
8) Radiator Fin Overheat Protection: The protection when it is detected that the internal
temperature of IPM is higher than 105℃. It is non-restorable if this protection occurs six times
9) Communication Fault: The adapting chip cannot communicate normally with inverter chip for
15s successively or cannot communicate normally with the main controller for 30 seconds
successively. This fault can be restored automatically.
3.2.2 Troubleshooting Process for Typical Inverter Faults
3.3 Typical Troubleshooting for Inverter URS-36, URS-45 and URS-50
1) DC Overvoltage: If it is detected that the DV voltage is higher than 420V upon energization,
2) DC Undervoltage: If it is detected that the DV voltage is lower than 200V upon energization,
3) PFC Abnormal: This fault is alarmed when it is detected that PFC module is abnormal 10
seconds after start of PFC. It is non-restorable if this protection occurs six times successively
in 1 hour. In this case, you must de-energize, discharge completely and re-energize before
you can eliminate this fault.
4) Inverter Module Resetting: The protection when it is detected of the change of compressor
parameters in inverter chip. This protection can be restored automatically.
5) Inverter IPM Protection: The protection when it is detected that the IPM module is abnormal.
It is non-restorable if this protection occurs six times successively in 1 hour. In this case, you
6) Inverter IPM Overheat Protection: The protection when it is detected that the internal
temperature of IPM is higher than 110℃. It is non-restorable if this protection occurs six times
7) Compressor Overcurrent Protection: This fault is alarmed when it is detected in 1ms
successively that the transient current of compressor is higher than 45A. It is non-restorable
if this protection occurs six times successively in 1 hour. In this case, you must de-energize,
8) Compressor in Loss of Synchronization: The protection when it is detected in 2s successively
that the negative potential of the compressor in run period is lower than 20V. It is
non-restorable if this protection occurs six times successively in 1 hour. In this case, you
9) Compressor in Loss of Phase: It is detected that the difference between estimated revolution
and preset revolution is over 199Hz.
10) Communication Fault between Inverter and Main Controller: It is detected in 60s
successively that the inverter cannot communicate with the main controller normally. This
fault can be restored automatically.
11) Current Detection Circuit Fault: This fault is alarmed when it is detected that the average bias
voltage is higher than 12.5% of 1.65V. It is non-restorable if this protection occurs six times
3.3.2 Troubleshooting Process for Typical Inverter Faults

3.3.2.1 PFC Board Abnormal
Manual controller
displays E5
(Overcurrent
protection)
Blink, ON, ON,

PFC Abnormal OFF, Blink, ON
Cut off the power for 1

minute or drop the bus Wrong judgment caused by
voltage to 36V or lower. Yes interference. Please check if
Then re-energize and start
the unit to run for a period there is source of interference
of time. Check if the fault nearby.
disappears?
No
Possible problem:
1. The temperature of PFC module is too high. Please check if the
PFC module is correctly tightened.
2. Input AC overcurrent protection. Please check if the voltage of
electric grid is too low.
3. The system is abnormal. Please check if the compressor or
system pressure is normal.
Make records correctly

and report.
Fig.3.3.2.1 Troubleshooting Process for PFC Board Abnormality
3.3.2.2 Inverter IPM Protection

The possible reasons causing inverter IPM protection include:
● The screw fixing the IPM is not ● The IPM module is damaged.
correctly tightened. ● The +15V voltage of power board is
● The radiation of IPM module is abnormal.
poor. ● Cable connection to PFC.
● The PFC module is abnormal. ● The compressor is abnormal.
● The resistor RS-RS6 on inverter
board is damaged.
● Interference
Manual controller
displays E5
(Overcurrent
protection)
ON, ON, ON,

IPM Protection Blink, Blink, ON
Cut off the power for 1 Wrong judgment caused by

minute or drop the bus
voltage to 36V or lower. No interference. Please check if
Then re-energize and start there is source of interference
the unit to run for a period nearby or if the wiring inside the
of time. Check if the fault
disappears? electric box is correct.
Yes
If the compressor is
started to run?
Yes No
1. Use monitor software to judge if the bus voltage De-energize for 1 minute and then check according
is normal? The normal voltage is 380V±10V. If to the following steps:
not, it is the fault of PFC board or its wiring fault. 1. Measure if the IPM module is damaged.
2. If the DC bus voltage is normal, de-energize for 1 Method: Remove the UVW wiring of the
minute and then check according to the following compressor and use multimeter to measure
steps: the resistance U-N, V-N, W-N, P-U, P-V and
1) Check if the screw fixing IPM module is P-W on inverter. It is normal if the resistance is
properly tightened. If not, it might result in over 1MΩ; otherwise the module is damaged
module overtemperature or IPM protection. and it is needed to replace the inverter.
2) If the screw fixing IPM module is properly 2. If the test in Step 1 shows that the IPM module
tightened, please check if +15V voltage of pin is normal, check the inverter and test the
CN11 on power board is stable. If lower than resistor RS1 ～ RS6 for any damage, e.g.
13.5, it can be determined that the power broken pin or burnt mark. If any, replace the
board has fault. Please replace the power inverter.
board. 3. If the tests in both Step 1 and Step 2 show that
3) If the above problems have been eliminated, it is normal, please check if +15V voltage of pin
check if the outdoor unit is well ventilated. If CN11 on power board is normal (The inverter
the outdoor temp. is too high under cooling can work normally only when this voltage is
mode, it may cause IPM protection due to higher than 13.5V). If not, replace the power
poor radiation of IPM module. board; otherwise, replace the diverter. Finish
4) Check if the radiator is dirty or blocked. If dirty the check and connect the wire properly.
or blocked, it may cause protection due to Re-energize the unit to start it again.
poor radiation of the module.
No Check if the
If the fault is eliminated? compressor is
normal.
Yes
Make records
correctly and
report.
Fig. 3.3.2.2 Troubleshooting Process for Inverter IPM Protection

3.3.2.3Tripping
Tripping
If the switch No
capacity meets
the
requirements?
Yes
Install electric
Tripping switch according to
No Tripping occurs No the capacity
occurs upon after start of required in the
energization? compressor? instruction manual.
Yes Yes
The leakage
Check the PFC board. Cut off current is too high.
the power. Cut off the power Please check for
for 1 minute or drop the bus moisture or
replace the filter.
voltage to 36V or lower. Then, Yes No
remove the wiring on PFC PFC is on?
board and use multimeter to
measure the P-N, P-L1_2,
P-L2_1, L1_2-N or L2_1-N on
PFC board for short circuit. Check the PFC board. Cut off
the power. Cut off the power
for 1 minute or drop the bus
voltage to 36V or lower. Then,
remove the wiring on PFC
Yes No board and use multimeter to
Short circuit? measure the P-N, P-U, P-V,
P-W, U-N, V-N or W-N on PFC
board for short circuit.
Replace PFC board if PFC module is damaged.

No
The leakage
Meanwhile, please check if the AC contactor is current is too
linked together and ensure no short circuit high. Please
between P-N. The possible reasons include: 1) replace the filter.
The screw fixing the module is not tightened. 2)
The AC contactor parallel to charging resistor on Yes
AC side is linked together, resulting in that the
transient charging current is too high upon
energization. 3) The input voltage is too low; 4) IPM Module is damaged and it is
The wiring is wrong. needed to replace the mainboard.
The possible causes include:
① The screw fixing the module is not
tightened; ② Severely overloaded;
No ③ Interference causes short circuit
Yes If the pre-stage
inside IPM module.
AC contactor is
linked together?
The system is abnormal:

Please check if the
PFC inductance No wiring or winding of the
insulation is compressor is short
damaged? circuited or incurred to
other faults
Yes
AC contactor is
Replace PFC Check if the
damaged. Replace
inductance wiring is wrong.
with the same
contactor.
Make records
correctly and
report.
Fig. 3.3.2.3 Tripping Inspection Process

3.3.2.4 Abnormal Noise from PFC Inductance
Generally, it is normal that the inductance will send out continuous and slight “ZHI ZHI” sound.
The abnormal noise of inductance refers to continuous “DU DU”, “PI PA” or “BI BI” sound easy to
hear by human ears. The possible reasons causing PFC inductance noise include:
● PFC fault
● Inverter output is abnormal.
Abnormal
Noise of PFC
PFC电感异响
Inductance
Abnormal
压缩机开
noise upon
异响？ of
start
compressor?
Yes
是
断电1分钟或
De-energize for 1
minute or drop the bus
母线电压降至
voltage to 36V or
36V以下后，
lower. Then, check
PFC 检查PFC板
board
If是否受潮、
wet, dirty or No
否
受污或器件
short
短路？
circuited?
是
Yes
Dry,烘干、清理污
clear off the dirt or
eliminate the short
物或清除短路
circuit. Reinstall and
start点，重新安装
to test.
并开机调试
No
否 Check the working
检查压缩机运
正常工作？
Work normally? status of
行状况
compressor.
是
Yes
1. If wet, find out the cause and take proper If the

1、如果是受潮，则要找出受潮原压缩机振动
compressor No
moisture proof measures. Dry the PFC 否
因，做好防潮措施，PFC板烘干后再
board and apply a layer of moisture proof 大或者异
vibrates heavily
or sends out
刷上防潮胶水；
adhesive. 响？noise?
abnormal
2. If dirty, find out the cause and take proper
2、如果是受污，则要找出受污原
measures to prevent dust. If the air of
因，并做好防尘处理，如果使用环境
environment is poor, please periodically
空气质量差，还要进行定期清理污是
Yes
remove the contaminants.
物；
3. If short circuited, find out the cause and
3、如果是短路，则要查出具体短路
clean the electric box to prevent the iron 驱动板坏，请更换
The inverter is PFC board is
原因，清理电器盒，防止铁屑等导电
scraps or other conductive substances PFC板坏，请更换
from attaching onto the board. 驱动板
damaged. Replace damaged. Replace
物质粘附在板上。 the inverter. PFC板
the PFC board.
Make records
Fig. 3.3.2.4 Troubleshooting Process for Abnormal Noise of PFC Inductance

3.3.2.5 Radiator Overheating Protection
E5
主板指示灯indicators
Mainboard
Monitor display
监控显示（LED1~LED6）
(LED1~LED5)
Radiator Blink, ON, ON,

散热器过热保护
overheat 闪亮亮亮闪亮
ON, Blink, ON)
protection
If the air outlet and air

If the
室外机散outdoor 如果室外机出风和
intake of the outdoor unit
radiator is in
热是否良 is回风短路，会使散
short circuited, it may
good
好？ cause poor performance
热器散热效果变差
condition?
of the radiator.
If the radiator is dirty or

If 散热器是
the radiator 如果散热器脏堵，
blocked, the radiation
is dirty or 会使散热器散热效
否脏堵？
blocked?
effect will become poor.
果变差
If the IPM If 如果IPM模块不打

the IPM module is not
IPM模块是
module is correctly
紧，会使模块温度tightened, it
may cause overheating
correctly
否打紧？过高，甚至烧毁模
tightened? of module or even burn.
块
If the silicate gel is not evenly

IfIPM模块硅
the silicate 如果硅胶涂覆不均，会使模块
coated, it will cause poor radiation
gel is evenly of the module, or wrong judgment
散热不良，或者温度分布不均
胶是否涂 due to uneven distribution of
coated on IPM 误判断，或者传感器检测不到
temperature, burn of module as
覆均匀？
module? 某些局部温度过高而烧毁模块
the sensor cannot detect regional
overheating.
If the silicate If 如果散热硅胶涂覆

the silicate gel is coated
IPM模块硅
gel on IPM too thick, it will also affect
太厚，也会影响散
胶是否满
module meets the radiation effect or
the 热效果，甚至烧毁
足要求？ even burn the module.
requirements? 模块
请检查感温包是否
Please check if the
temperature
失效，或者重新安 sensor
fails, or reinstall the
装模块并打紧
module and tighten
it.
Make records
correctly and
report
Fig. 3.3.2.5 Troubleshooting Process for Radiator Overheating Protection

3.3.2.6 DC Bus Overvoltage Protection
Manual
手操器显示E5
controller
Displays E5
（过流保护）
(Overcurrent
Protection)
主板指示灯indicators
Mainboard
Monitor监控显示
display （LED1~LED6）
(LED1~LED5)
DC Bus
直直直直直直 ON, ON, ON,
Overvoltage 亮亮亮亮闪亮
ON, BLINK,
直直直
Protection ON
The voltage of electric grid is

电网电压过高，请立即
If输入电压是否在运行
the input voltage is No too high. Please immediately
within work range 否断电，不能上电运行，
cut off the power and do not
范围内（185～
(185~264VAC)? 否则可能会损坏机组或
energize. Otherwise, the unit
264VAC）？ might be damaged or fire will
be发生火灾！
caused!
是
Yes
Does it occur during

压缩机运行过程中 of
operation
出现？
compressor?
是
Yes No
否
Does it1个小时内
occur repeatedly Does it occur upon
within 1 hour? 压缩机降频时出现？
reduction of compressor
出现多次？ frequency?
Yes
是 No
否 Yes
是 No
否
PFC board is abnormal.

PFC板异常，请检查PFC Caused by interference. Caused upon reduction of PFC board is abnormal.
PFC板异常，请检查PFC
Please check of the resistor 干扰引起，请检查走线或
Please check the wire route 压缩机减速时引起，如果
compressor speed. If this Please check of the resistor
板上电压采样电路中的电
R6, R3 and R9 on voltage or determine the source of occurs frequently, please 板上电压采样电路中的电
R6, R3 and R9 on voltage
确定干扰源，并加强抗干经查出现，请检查压缩机
阻R6、R3、R9是否异
sampling circuit of PFC interference and take check if the compressor is 阻R6、R3、R9是否异
sampling circuit of PFC
board is abnormal, or 扰措施
measures to prevent 是否异常
abnormal. board is abnormal, or
常，或者更换PFC板
replace the PFC board. interference. 常，或者更换PFC板
replace the PFC board.
Make records
Fig. 3.3.2.6 Troubleshooting Process for DC Bus Overvoltage Protection

3.3.2.7 DC Bus Undervoltage Protection
Manual
手操器显示E5
controller
（过流保护）
Displays E5 E5
(Overcurrent
Protection)
主板指示灯 indicators
Mainboard
Monitor display
监控显示（LED1~LED6）
(LED1~LED5)
DC
直直直直直 Bus ON, BLINK,
Undervoltage 亮闪闪亮闪亮
BLINK, ON,
直直直直
Protection BLINK, ON
The voltage of electric grid is

电网电压过低，请立即
If输入电压是否在运行
the input voltage is too low. Please immediately
within work range No
否断电，不能上电运行，
cut off the power and do not
范围内（185～ energize. Otherwise, the unit
(185~264VAC)? 否则可能会损坏机组或
264VAC）？ might be damaged or fire will
be发生火灾！
caused!
是
Yes
Does it occur during
压缩机运行过程中 of
operation
compressor?
出现？
是
Yes No
否
Does it occur
1个小时内
repeatedly within 1 Does it occur upon
压缩机启动时出现？
start of compressor?
hour?出现多次？
是
Yes No
否是
Yes No
否
PFC board is abnormal. Caused by interference. The input voltage is at the PFC board is abnormal.
PFC板异常。输入电压处于低电压临界
lower limit. Please check if
PFC板异常。
1. Please check of the
1. Please check of the resistor R6, 干扰引起，请检查走线或
Please check the wire route
1、请检查PFC板上电压采样电路
R3 and R9 on voltage sampling or确定干扰源，并加强抗干
determine the source of 点，请检查电源线线径是
the wire diameter conforms 1、请检查PFC板上电压
resistor R6, R3 and R9 on
to requirements, or if the
否符合要求，或者线长是 voltage sampling circuit of
采样电路中的电阻R6、
中的电阻R6、R3、R9是否异常；
circuit of PFC board is abnormal. interference
扰措施
and take wire is too long thus
measures to prevent PFC board is abnormal.
2. Please check if the wiring on PFC
2、请检查PFC板与驱动板接线是否太长以至于分压严重。
resulting into severe R3、R9是否异常；
2. Or replace the PFC
board and inverter is loose, broken interference. diversion of the voltage
否松脱或断路或接触不良；
or in poor contact.
2、或者更换PFC板。
board.
3、或者更换PFC板。
3. Or replace the PFC board.
Make records
correctly and report
Fig. 3.3.2.7 Troubleshooting Process for DC Bus Undervoltage Protection

3.4 Troubleshooting for Typical Faults of Inverter URT-24, URT-36, URT-45, URT-50and
URT-60
The model of mainboard used in this system is as follows:
ZB WZ863 Fig7
ZB Z814B Fig8
ZB WZ814A Fig9
3.4.1 WZ863 PCB Fault Code
Table 3 WZ863 PCB LED Indication Code

Display
WZ863 PCB LED Indication
Indication
Item
LED1 LED2 LED3
(red) (yellow) (green)
11 Normal Mode Blink OFF OFF E5
IPM Module Protection Blink OFF Blink E5
Voltage Protection Blink Blink OFF E5
Compressor Current Protection Blink Blink Blink E5
Communication Fault from Inverter
OFF Blink Blink E5
to Main Controller
Loss-of-Synchronization Protection Blink ON ON E5
Current Sensor Fault Blink Blink ON E5
Sensor Connection Protection ON ON Blink E5
Radiator Fin Overheat Protection ON Blink ON E5
Radiator Fin Sensor Fault OFF Blink ON E5
Wrong Mode ON OFF Blink E5
3.4.2 Troubleshooting for Inverter Faults

1) IPM Module Protection: This protection occurs as long as it is detected that the FO
of IPM module has low level. It is non-restorable if this protection occurs six times
successively in 1 hour. In this case, you must de-energize, discharge completely
and re-energize before you can eliminate this fault.
2) Voltage Protection: When there is no other fault 2s after energization, it is detected
for 2ms successively that the bus voltage is higher than 725V or lower than 375V. It
is non-restorable if this protection occurs six times successively in 1 hour. In this
case, you must de-energize, discharge completely and re-energize before you can
eliminate this fault.
3) Compressor Current Protection: When there is no other fault 2s after energization, it
is detected for 600us successively that the transient current of compressor is higher
than 48A. It is non-restorable if this protection occurs six times successively in 1
hour. In this case, you must de-energize, discharge completely and re-energize
before you can eliminate this fault.
4) Communication Fault from Inverter to Main Controller: The inverter cannot
communicate normally with the main controller for 12s successively. This fault can
be restored automatically.
5) Loss-of-Synchronization Protection: When there is no other fault, it is detected for
2s successively that the negative potential is lower than 20v during operation of the
compressor. It is non-restorable if this protection occurs six times successively in 1
hour. In this case, you must de-energize, discharge completely and re-energize
before you can eliminate this fault.
6) Current Sensor Fault: When there is no other fault 2s after energization, it is
detected in 1s that the average bias voltage is higher than 20% of 3V. It is
non-restorable if this protection occurs six times successively in 1 hour. In this case,
you must de-energize, discharge completely and re-energize before you can
7) Sensor Connection Protection: The current sensor is not connected to
corresponding U or V phase, or the direction of connection is incorrect.
8) Radiator Overheat Protection: When there is no other fault 2s after energization, it is
detected for 2ms successively that the radiator temperature is higher than 90℃. It is
non-restorable if this protection occurs six times successively in 1 hour. In this case,
you must de-energize, discharge completely and re-energize before you can
9) Radiator Sensor Fault: When there is no other fault 2s after energization, it is
detected for 2ms successively that the radiator sensor is short circuit or open circuit.
It is non-restorable if this protection occurs six times successively in 1 hour. In this
case, you must de-energize, discharge completely and re-energize before you can
10) Mode Error: The main control board and inverter is not under quick measuring
mode at the same time, or the main control board and inverter is not under normal
mode at the same time.
3.4.3 WZ863 PCB Troubleshooting
3.4.3.1 Inverter Module Protection
The possible reasons causing inverter module protection include:
● The screws fixing IPM module ● The IPM module is damaged.
are not correctly tightened. ● +15V voltage of power board is
● Radiation of IPM module is poor. abnormal.
● Interference. ● The compressor is abnormal.

Manual
手操器显示E5
controller
（过流保护）
Displays E5 E5
(Overcurrent
Protection)
主板指示灯
Mainboard indicators 驱动板指示灯
Inverter Board Indicators
(LED1~LED6)
（LED1~LED6） (LED1~LED3)
（LED1~LED3）
监控显示
Monitor display
ON, ON, ON,

亮亮亮闪闪亮
BLINK, BLINK,
闪灭闪 OFF,
IPMIPM保护
Protection BLINK
BLINK, ON
断电1分钟或母线电
Cut off the power for 1 minute or 干扰引起的误判断，请
Wrong judgment caused by
drop the bus voltage to 36V or
压降至36V以下再上
lower. Then re-energize and
No
否 interference. Please check if
检查周围是否有干扰源
there is source of interference
start the unit to run for a period
of电，开机运行一段时
time. Check if the fault
或者电器盒内走线是否
nearby or if the wiring inside the
间后故障复现？
reoccurs? 规范 box is correct.
electric
是
Yes
If the compressor is
压缩机是否启动
started to run?
并运行？
是
Yes No
否
一、检查接线L1，L2，L3，N是否接对。
1. Check if the wiring on L1, L2, L4 and N is correct.
De-energize for 1 minute and then check according
二、用万用表检测输入电源质量，观察两
2. Use multimeter to test the quality of input power and check
to the following steps:
if there is significant fluctuation between two power cables.
两电源线之间是否有较大波动。 1. Measure if the IPM module is damaged.
3. If the above are normal, de-energize for 1 minute and then
二、若上述都正常，则断电1分钟后按如下
check according to the following steps: 断电1分钟后按如下步骤检查：
Method: Remove the UVW wiring of the
步骤检查：
1) Check if all the wires in inverter board are securely 1、测量IPM模块是否损坏，方法是：卸下
compressor and use multimeter to measure
fixed.
1、检查驱动板中的接线是否全部接牢固；压缩机UVW三相接线和PN接线，用万用表
the resistance U-N, V-N, W-N, P-U, P-V and
2) Check if the screw fixing IPM module is properly
2、检查固定IPM模块的螺钉是否打紧，如
tightened. If not, it might result in module 电阻档分别测量驱动板的U-N、V-N、W-
P-W on inverter. It is normal if the resistance
未打紧，会引起模块温度过高或者IPM保
overtemperature or IPM protection. N、P-U、P-V、P-W间阻抗值，若在1MΩ
is over 1M Ω ; otherwise the module is
护； 3) Check if the silicate gel on the bottom of IPM module 以上则正常，否则模块坏，需更换驱动
damaged and it is needed to replace the
is evenly coated.
3、检查IPM模块底下的硅胶是否涂均匀；
4) Take special care to check if the pin seat of inverter
板； inverter.
4、特别检查驱动板U14模块针座是否接好
U14 module is correctly connected. 2、检查驱动板中的接线是否全部接牢固；
2. Check if all the wires in inverter board are
5、检查散热器是否脏堵，如果脏堵会引起
5) Check if the radiator is dirty or blocked. If dirty or 3、特别检查驱动板U14模块针座是否接好
securely fixed.
blocked, it may cause protection due to poor
模块散热不良而保护。请更换驱动板；
3. Take special care to check if the pin seat of
radiation of the module.
6、如上述问题都已排除，则检查室外机通
6) If the above problems have been eliminated, check if
inverter U14 module is correctly connected.
风是否良好，在制冷时，室外温度太高会
the outdoor unit is well ventilated. If the outdoor NIf not, replace the inverter.
使IPM模块散热不良引起保护。
temp. is too high under cooling mode, it may cause
IPM protection due to poor radiation of IPM module.
If the fault is 否
No Check if the
检查压缩机是
故障排除？
eliminated? compressor is
否正常
normal.
是
Yes
Make records
Fig. 3.4.3.1 Troubleshooting Process for Inverter Module Protection

3.4.3.2 Tripping
跳闸
Tripping
If the switch No
所接开关是否满足要
capacity meets the 否
求？
requirements?
是
Yes
Install electric
Tripping occurs 请按说明书
switch
Tripping occurs No
否压缩机开启后才跳 No
否要求安装电
upon上电就跳闸？
energization? after
闸？
start of according to
compressor? 是气开关
instruction
manual.
是
Yes 是
Yes
1. Check the wiring L1, L2, L3 and N. 1. If the environment temperature of

Check if the earthing wire is air switch is too high?
一、检查接线L1，L2，L3，N，地线
connected. 2. If the IPM module or compressor
是否接对。
2. Use multimeter to measure L1, L2, is short circuited to earth?
L3, N and earthing wire for short
二、用万用表检测L1，L2，L3，N、 3. If the IPM module or inverter is
circuit.
地线两两之间是否有短路现象 damaged.
Steps: 一、空开所在环境温度是否太高？
步骤如下：
1) Check if the filter board is burnt.
1、检查滤波板是否有烧黑现象二、IPM模块或压缩机是否对地短
2) If the bridge rectifier is
2、整流桥是否损坏damaged. 路？
3、整机其它负载是否短路和对地短路
3) If the other loads of complete 二、IPM模块或驱动板是否损坏？
现象 unit and the earthing are short
circuited.
三、检查交流接触器是否粘连？
3. Check if the AC contactor is linked
together.
Make records
Fig.3.4.3.2 Tripping Inspection Process

3.4.3.3 DC Bus Overvoltage Protection and DC Bus Undervoltage Protection
Manual
手操器显示E5
controller
displays E5
主板指示灯
(LED1~LED6)
（LED1~LED3）
监控显示
Monitor display
DC Bus Overvoltage ON, ON, ON,
直流母线电压过高保护亮亮亮亮闪亮
ON,BLINK, ON,
Protection or DC Bus BLINK, BLINK,
或 or ON,或 BLINK, 闪闪灭
Undervoltage Protection BLINK, ON, ON
直流母线电压过低保护亮闪闪亮闪亮
BLINK, ON
If the voltage of input 是

Yes The voltage of electric grid is
输入电源电压是否在电网电压过高，请立即
too high. Please immediately
power is within 320V～
320V~457V以内？
457V? 断电，否则会损坏机组
cut off; otherwise, the unit
may be damaged.
否
No
Yes
是 Fault occurs upon No
否
一上电就显示故障
energization. If压缩机开机后
it is displayed after
start才显示
of compressor.
是
Yes If the filter is If the filter is 是
Yes
滤波是否有损坏滤波是否有损坏
damaged.
damaged.
否
No 否
No
是
Yes If the bridge rectifier If the AC contactor is 是
Yes
is 整流桥是否损坏
damaged 交流接触器是否卡死
clogged.
No
否否
No
是
Yes 是
Yes
If the cement resistor If the capacitor fails.
水泥电阻是否短路电容是否失效
is short circuited.
否
No 否
No
Yes
是 If驱动和模块是否接对
the inverter and No
否
module are correctly
wired. 线
Replace the switch

更换相关器件或重新接 Replace relevant
components or connect the 更换驱动板
Replace the inverter. 更换相关器件
线 components.
wires again.
Make records
Fig. 3.4.3.3 Troubleshooting Process for DC Bus Overvoltage Protection and DC Bus
Undervoltage Protection
3.4.3.4 Radiator Overheating Protection
Manual
手操器显示E5
controller
displays E5
主板指示灯
(LED1~LED6)
（LED1~LED3）
监控显示
Monitor display
Radiator BLINK, ON, OFF, BLINK,

散热器过热保
Overheating 闪亮亮亮闪亮
ON, ON, 灭闪亮
护
Protection BLINK, ON ON
If the outdoor radiator is If如果室外机出风和回风

the air outlet and air intake
室外机散热是否良 No
否 of短路，会使散热器散热
the outdoor unit is short
in good condition?
好？ circuited, it may cause poor
效果变差。
performance of the radiator.
Yes
是
If the radiator fin is dirty 如果散热片脏堵会使散

If the radiator is dirty or
散热片是否脏堵？
or blocked? 热效果变差
blocked, the radiation
effect will become poor.
否
No
If the radiator fin sensor

检查散热片感温包是否
fails or if it is inserted
失效或接插良好
properly.
Make records
Fig. 3.4.3.4 Troubleshooting Process for Radiator Overheating Protection

3.4.3.5 Sensor Connection Protection
Manual
手操器显示E5
controller
displays E5
主板指示灯
(LED1~LED6)
（LED1~LED3）
监控显示
Monitor display
Sensor
传感器连接保 BLINK, ON, ON, ON,
Connection 闪亮亮闪闪亮
ON. BLINK, 亮亮闪
护
Protection BLINK
BLINK, ON
If the compressor wires 是

Yes
U,压缩机线U，V，W
V and W are
connected
顺序是否接对？ in correct
sequence?
否
No
If the U-phase wire of

compressor
U相压缩机线是否穿 passes the
U-phase current sensor,
过U相电流传感器
and if the V-phase wire 是
Yes
和
of compressor passes
the V-phase current
V相压缩机线是否穿
sensor.
过V相电流传感器
否
No
If the compressor 是
Yes
压缩机绕组是否短
winding is short
circuited, or open circuit
路，对地断路
to the ground.
否
No
If IPM module is
Yes
是
IPM模块是否损坏
damaged.
No
否
更改相关部
Change relevant
更换驱动板
Replace the inverter.
件
components.
Make records
Fig. 3.4.3.5 Troubleshooting Process for Sensor Connection Protection

Appendix: Interface Diagram for Each Mainboard
Silkscreen Interface
AC-L Power Live Wire
AC-N Power Neutral Wire
CN12 Outdoor Ambient Sensor
CN14 Condenser Temp. Sensor
CN25 Exhaust Temp. Sensor
X2（LPP） LV Protection Switch
ZB1 WZ4D35 X4(OVC1) HV Protection Switch
ZB1 WZ4D15 X8(LVCC) Overload Protection Switch on Compressor
X11 4-way Valve
X13 AC Contactor
X15 Outdoor Fan
X16 Compressor with Electric Heater
CN17 Electronic Expansion Valve
CN65、CN66、CN67 Communication Wire
Fig 1 ZB1 WZ4D35, ZB1 WZ4D15 PCB Interface Diagram
X2 Power Live Wire
X1 Power Neutral Wire
CN4 Outdoor Ambient Sensor
CN6 Condenser Temp. Sensor
CN5 Tube Temp. Sensor
WZ4D35A X5﹑X6 Overload Protection Switch on Compressor
WZ4D15A X14 4-way Valve
X12﹑X13 Outdoor Fan
X8、X9、X10 Compressor Interface
X3、X4、X15、X24 PFC Inductance Interface
CN11 Electronic Expansion Valve
CN8、CN9、CN10 Communication Wire
Fig 2 Interface Diagram for Mainboard 50 or Below
X1 DC-BUS(+)
X2 DC-BUS(-)
X3、X4、X5 Compressor Interface
ZQ101 CN1、CN5 Communication Interface
CN4 Drive IC Power
CN6 Communication Power
CN3 PFC Interface
Fig 3 ZQ101 PCB Interface Diagram

L1_1 Inductance Brown Line
L1_2 Inductance White Line
L2_1 Inductance Yellow Line
Z81P L2_2 Inductance Blue Line
J8 Capacitance Positive
J7 Capacitance Cathode
J3 AC-L
J4 AC-N
X1 PFC Interface
Fig. 4 70 Unit PFC Interface Diagram

X3 Inductance Brown Line
X8 Inductance White Line
X7 Inductance Yellow Line
Z81PA X2 Inductance Blue Line
X5 Capacitance Positive
X6 Capacitance Negative
X4 AC-L
X2 AC-N
CN1 PFC Interface
Fig5 100～160PFC Interface Diagram and Chart

X1 DC-BUS(+)
X2 DC-BUS(-)
X3 Compressor Interface
ZQ201 CN1、CN2 Communication Interface
CN4 Drive IC Power
CN6 Communication Power
CN3 PFC Interface
Fig.6 ZQ201 PCB Interface Diagram

Communication
Interface AC contactor Power L N
Connect to
IPM P
LED
Connect to
Z814B PCB
CN8
IPM Interface Connect to

Z814B PCB
CN3
U phase V phase Radiator

Sensor Sensor Sensor
P To DC bus, for measuring the Vdc.
CN15 Power supply from switch power
U14 Quick connector of module
CN1 Power supply from switch power
485 communication, for communicating
WZ863
with main control board (Different
CN8,CN9,CN3
interface shall be selected if matched to
different main control boards)
CN11 Power 220V
CN2 AC contactor control interface
IU To U-phase current sensor
IV To V-phase current sensor
CN17 Radiator Temp. Sensor
Fig.7 Three-phase Inverter (ZB WZ863) Interface Diagram
Connect to
WZ863
PCB CN1
Power N
Power L Connect to
WZ863 PCB
CN15
X1 Live Wire
X2 Neutral Wire
Z814B CN8 To 14-cord Wire
CN3 To 3-cord Wire
Fig8 ZB Z814B Interface Diagram
用 FinePrint 打印 - 可在 www.fineprint.com.cn 订购
Power Out N L3 L2 L1
GND
Power IN N L3 L2 L1
AC_L1 Inlet L1
AC_L2 Inlet L2
AC_L3 Inlet L3
N Inlet N
L1_OUT Outlet L1
WZ814A
L2_OUT Outlet L2
L3_OUT Outlet L3
N_OUT Outlet N
Fig9 ZB WZ814A Interface Diagram
3 Installation and Debugging
3.1 Installation of Outdoor Unit

3.1.1 Selection and Requirements of Installing Location
Fig.3-1-1
The unit shall so installed that enough space shall be maintained around to ensure good
air return and heat radiation. To ensure proper operation of the unit, the selection of
installing position must be in strict accordance with the following principles:
◆The outdoor unit shall be installed at a position where the exhaust air will not flow back.
Around the machine, maintain enough space for repair work.
◆ The install position must be well ventilated so that the machine can suck and discharge
enough air. Ensure there is no obstruction at the air inlet and outlet of the machine. If any,
remove the obstructions blocking the air flow.
◆ The installing position shall be strong enough to support the weight of outdoor unit.
Sound insulation and shock absorption shall be provided. Make sure that the outlet air
and noise from the unit will not affect the neighbor.
◆ The outdoor unit must be lifted from the designated hoisting hole. During lift, take care
to protect the machine. To prevent rusting in the future, it is prohibited to damage the
plating parts.
◆Avoid direct sunshine.
◆The installing positions must be able to drain the rainwater and defrost water.
◆ The installing position shall ensure that the machine will not be buried under the snow
or affected by wastes or oil fog.
◆ To meet the noise and vibration requirements, install the outdoor unit with rubber
damping cushion or spring damper.
◆The installation size shall conform to the specification. The outdoor unit must be fixed at
the position where it is installed.
The installation shall be carried out by professional technicians.
3.1.2 Precautions on Installation of Outdoor Unit
1) Fix the outdoor unit with M10 bolts and nuts if it is installed on solid ground like
concrete. And ensure that the outdoor unit is vertically standing and well leveled.
2) Do not install the unit at the top of the construction.
3) If noise is heard from vibration, please add rubber cushion between outdoor unit and
installation base.
4) When operating under heating or defrosting mode, the outdoor unit shall be provided
with water drainage treatment.
5) To install the water drainage pipe, please insert the drainage connector to the
drainage hole on the chassis of outdoor unit and then connect a drainage hose to the
drainage connector. (If drainage connector is used, the installing height of outdoor
unit shall be 5cm at least).
3.1.3 Installation of Connection Pipe
Selection of connection pipe, as shown in Table 3-1
Table 3-1
Item Pipe Size (mm) Max. Max. Height Difference Additional Refrigerant
Pipe between Indoor and (Excessive Length of
Model Liquid Pipe
Gas Pipe Length (ｍ) Outdoor Unit (ｍ) Pipe)
管 (管长超标部分)
URS-09 1/4＂ 3/8＂ 20 15 15
URS-12
1/4＂ 1/2＂ 20 15 20
URS-18
URS-24 φ9.52 φ16 30 15 60g/m

型号
URS-36 URT-36 URS-36
GUHD36NK3AO
URS-45 GUHD36NK3AO
URT-45 φ12 φ19 50 30 120g/m
GUHD36NK3AO GUHD24NK3AO
URS-50 URT-50
URT-60 φ12 φ22 50 30 120g/m
The layout of connection pipes shall be based on site conditions in reference to the
following principles:
1. Shorten the length of connection pipe to minimum, best within 5m.
2. Reduce the height difference of indoor and outdoor units to minimum.
3. Reduce the elbows of connection pipe to minimum.
4. If the connection pipe is longer than 20m, it is needed to check if the lubricating oil of
the system is enough. Add if needed.
5. The refrigerant quantity inside this unit is suitable to connecting pipe 7m long. If the
length of connection pipe is increased, add appropriate quantity of refrigerant
accordingly. For each increase of the pipe length by 1m, the quantity of refrigerant to
be added is shown as below. The max. permissible pipe length is 30m.

6. If the air conditioner is installed when the height difference between indoor and
outdoor units is more than 10m, one oil return elbow shall be installed every 6 meters.
The height of indoor unit is different from that of outdoor unit, please arrange the pipes
according to the diagram below.
Liquid pipe (i.e. small pipe)
- - - - - - Gas pipe (i.e. large pipe)
Outdoor unit
Oil elbow of gas
pipeGas Pipegas
One oil elbow
Pipegas PipeGas Pipe
every 4~6m
Oil-kept bend of gas
pipe
Indoor unit
Outdoor unit higher than indoor unit
Fig. 3-1-2
1) Connection of Pipe
a) The connection pipe must meet the following requirements:

The three basic principles are to keep the pipe dry, clean and airtight.
Fig. 3-1-3
b) Align the flare of copper tube with the center of threaded connector and
adequately tighten the flaring nut with your hands.
c) Use torque wrench to tighten the flaring nut until a “KA TA” sound is heard, as
shown in Fig. 3-4. The torque for tightening of nut is shown in 3-1-5.
Gas 1-way
Liquid valve valveGa valve
s valve
Indoor pipe Flaring nut Pipe
Valve
cap
Valve
Inner hexagonal stem
Screwdriver
wrench
Wrench Torque wrench
Fig. 3-1-4 Fig. 3-1-5

Table 3-2
Pipe Dia. Tightening Torque
1/4＂ 15-30 (N·m)
3/8＂ 35-40 (N·m)
5/8＂ 60-65 (N·m)
1/2＂ 45-50 (N·m)
3/4＂ 70-75 (N·m)
d) The bend of pipe shall not be too small; otherwise the pipe might be cracked.
Please use pipe bender to bend the pipe.
e) The pipe shall be welded by facing the joint upward or horizontally. Avoid facing
the pipe opening downward during weld (The downward welding is easy to
cause defect and affect quality, or even cause leakage).
Fig. 3-1-6
f) Use sponge to wrap the connection pipe and connectors and tie with plastic
tapes.
2) Vacuum and Leakage Detection

a) Remove the cap on liquid valve and gas valve.
b) Align the center of pipe and adequately tighten the nuts of connection pipe with
your hands.
c) Tighten the nuts with wrench.
d) Remove the 1-way valve cap on gas valve.
e) Use inner hexagonal wrench to loosen the element of liquid valve by rotating it
for 1/4 turn. Meanwhile, use screwdriver to prop up the element of gas valve until
the air is discharged.
f) Discharge the air for 15 seconds until refrigerant occurs. Then, immediately
close the 1-way valve and tighten the valve cap.
g) Completely open the element of liquid valve and air valve, (as shown in Fig.
3-1-5).
h) Tighten the valve cap. Then use soap water or leakage detector to check if any
air leaks out from the indoor / outdoor unit or pipe connection.
i) If possible, it is best to discharge the air from the valve position by using vacuum
pump, as shown in Fig. 3-1-7.
压力计
Pressure gauge 压力计
Pressure gauge
"LO"旋钮
LO Knob "HI"旋钮
HI Knob
液阀
Liquid valve
Vacuum
真空泵pump
连接软管 hose
Connection
气阀valve
Gas
Fig. 3-1-7
3) Installation of Protective Sheath on Connection Pipe
a) To avoid condensing or leakage on connection pipe, the gas pipe and liquid pipe
must be insulated from the air by wrapping with hat insulation and adhesive
tapes.
b) The connector to indoor unit shall be wrapped by heat insulation materials to
ensure no clearance with the wall of indoor unit, as shown in Fig. 3-1-8.
No
无间隙clearance
Fig. 3-1-8 Fig. 3-1-9
c) Use adhesive tape to bundle the connection pipe and cable together. To avoid
outflow of condensate water from the drainage pipe, the drainage pipe shall be
separated from connection pipe and cable.
d) Wrap heat insulation tape from the bottom of outdoor unit until the upper end of
the pipe is deep into the wall. When wrapping the heat insulation tape, please
compress each circle to half of the previous circle, as shown in Fig. 3-1-9.
e) Use the pipe clamp to fix the wrapped pipe onto the wall.
Note: 1. After the pipe is properly protected, never bend the pipe to a very small angle;
otherwise the pipe might be cracked or broken.
2. Wrapping of the protective tape too tight may reduce the heat insulation
effect. Make sure that the condensate drainage pipe is separated from the
pipe bundle.
3. After completing the protection work and wrapping the pipe properly, use
sealing materials to seal the holes in the wall, thus to prevent rain from
invasion into the room.
3.2 Requirements for Installation of Duct Type Indoor Unit

3.2.1 Accessories for installation of duct type indoor unit, as shown below:
Name and Shape QTY Description
Operating and Installation Instructions 1
Heat insulation materials for air connector 1 For gas pipe connector of indoor unit
Heat insulation materials for liquid connector 1 For liquid pipe connector of indoor unit
Heat insulation materials for drainage pipe 2 For condensate water pipe and rubber plug
Nut M8 with washer 8 For fixing the hook
Nut M10 with washer 4

4 sets, for fixing the indoor unit to ceiling
Nut and spring gasket 4
Hook 4 For fixing the indoor unit to ceiling
String 4 or 8 pcs 4 pcs for 2hp unit and 8 pcs for others
Wired Controller 1
Remote controller 1
Battery 2
0 for 2hp unit, 2 pcs for 2.5－3hp unit and 4
Corrugated pipe 0, 2 pcs or 4 pcs
pcs for 4－5 hp unit
Power cable 1－2 pcs 2 pcs for 4－5 hp unit and 1 pc for others
Connection wires 2－3 pcs 3 pcs for 4－5hp unit and 2 pcs for others
3.2.2 Size of Installation Space
Nut with washer Spring washer for nut
Indoor Unit
Fig. 3-2-1
3.2.3 Installation of Indoor Unit
3.2.3.1 Select the location of installation
1) Ensure that the top hanger frame has enough strength to support the weight of
the unit.
2) The drainage pipe shall be easy to drain water.
3) There shall be no obstacle at the inlet and outlet so as to keep the air in good
circulation.
4) Ensure the space needed for installation, repair and maintenance works.
5) Select a place far from heat source, flammable gas or smoke.
6) The machine is ceiling mounted (Concealed installed in the ceiling).
7) The indoor unit, outdoor unit, power cord and connection cable shall be kept 1m
at least from the TV set or radio. This is to prevent image interference and noise
on above appliances.
3.2.3.2 Installation of Air Conditioner Body and Check of Indoor Unit Level
1) Install the expansion bolt
Drill four holes (Dia. 10mm approx.) on the ceiling. Refer to Fig. 3-2-2 for the spacing
between the holes. Insert M10 expansion bolt into the hole and then punch the iron nail
into the bolt as shown in Fig. 3-2-3.
吊装螺钉
Mounting screw 机组
Unit
挂钩
Hook
Fig. 3-2-2 Fig. 3-2-3
2) Install the hook to indoor unit. See Fig. 3-2-4

3) Install indoor unit to the ceiling. See Fig. 3-2-5
螺杆
Screw rod
挂钩
Hook
螺母
Nut
Air 送风口
outlet 螺母
Nut
Fig. 3-2-4
≤48mm
Fig. 3-2-5
4) Check of Indoor Unit Level

After completing the installation of the indoor unit, be sure to check the level of the
complete unit so as to make the front, back, left and right of the unit on the same level.
See 3-2-6.
Level Gauge
水平检测仪
Fig. 3-2-6
3.2.3.3 Installation of Duct
1) Install the rectangular duct. See Fig. 3-2-7
1 3 6
2
回风
Air Intake Air 回风
Intake Air 送风
Outlet
3
5 7
4
Fig. 3-2-7
S/N Description S/N Description
1 Hanger Bar 5 Filter
2 Intake Pipe 6 Main Outlet Pipe
3 Canvas Duct 7 Air Outlet
4 Air Intake
2) Install the round duct. See Fig.3-2-8
1
2
3
4 5 6 7 8 9
1 Hanger Bar 6 Transition Duct
2 Intake Pipe 7 Air Outlet Pipe
3 Canvas Duct 8 Diffuser
4 Intake Louver 9 Diffuser connector
5 Air Outlet
Fig. 3-2-8
Note: Shown above is the installation of rear air intake. Bottom air intake may be used
according to the needs of actual installation. The installation method is similar to that of
rear air intake. In all intake pipes, at least one shall be kept open. Round duct may also be
adopted and round heat insulation hose may be used to blow the air to each room. Heat
insulation shall be provided for both outlet pipe and intake pipe.
3.2.3.4 Installation of Fresh Air Pipe (Limited to extra residual pressure unit with a
cooling capacity over 6000W)
1) To connect the fresh air pipe, cut off the fresh air baffle firstly, as shown in Fig. 3-2-9
(a). If fresh air pipe is not required, use sponge to seal the seam on fresh air baffle.
2) Mount a round flange for connection of fresh air pipe. See Fig. 3-2-9 (b).
3) Both the duct and round flange need good sealing and heat insulation.
4) The fresh air shall be filtered air.
去除 Round Duct
Remove 圆形风管
新风挡板
Fresh air baffle
去除
Remove
(a) (b)
Fig. 3-2 -9
3.2.3.5 Installation of Intake Pipe
1) The square flange is factory mounted at the rear part, while the cover of air intake is
mounted at the bottom. See Fig. 3-2-10.

方形发兰
Square Flange
后部回风
Rear Air Intake
下部回风
Bottom Air Intake
回风盖板
Air Intake Cover Plate
Fig. 3-2-10
2) If bottom air intake is required, just change the position of square flange and air intake
cover.
3) Rivet the intake pipe to the air intake of indoor unit and another end to the intake
window. For free adjustment of the height, you may fabricate a section of canvas duct
and reinforce with 8# iron wires in folded form. The user may select the installation
method in unified consideration of the constructions and maintainability. See Fig.
3-2-11.
5 4 5 3
送风 2 送风
Air Outlet Air Outlet
4 6 1 回风
1 Air Intake
回风
Air Intake

１ Intake Window ４ Indoor Unit
２ (with filter)
Canvas Duct ５ Outlet Pipe
３ Intake Pipe 6 Test Grill
Fig. 3-2-11
3.2.3.6 Installation of Round Outlet Pipe

Fig. 3-2-12
3.3 Requirements for Installation of Ceiling-seated Indoor Unit
3.4 Requirements for Installation of Well Type Indoor Unit
Two heights available, i.e. 260mm and 340mm

The unit shall be so installed that the front panel must be tightly sealed to the body.
Roof
Hoisting stand
Within 300mm 1-1.5m below280mm
Drain hose
below500mm
Drain raising
.
hose
220mm
.
Ceiling Clamp(attachment)
Position and Requirements of Condensate Pipe

3.5 Other Accessories and Auxiliary Requirements
3.5.1 Installation of Condensate Pipe
1) The condensate pipe shall be kept an inclination 5~10°for easier drain of the
condensate water. To prevent condensed dew, the connector of condensate pipe
shall be heat insulated. (See Fig. 3-5-1)
2) One condensate outlet is provided on the left and right side of the indoor unit
respectively. After the condensate outlet is determined, please use rubber plug to
block the outlet on another side and fix with tie strap to prevent leakage. Wrap
properly with heat insulation materials.
3) The right condensate outlet is factory blocked by rubber plug.
Heat Insulation
冷凝水管 Layer of
保温层
Condensate Pipe
管盖
Pipe Cove
Fig. 3-5-1
3.5.2 Installation and Connection of Wired Controller

1) Firstly, select the installing location. According to the size of communication wire for
Wired Controller, reserve a groove or cable hole for embedding of communication
wire.
2) For open installation of the communication wire between Wired Controller (85 X 85
X16) and indoor unit, you may use 1# PVC pipe and set up an appropriate groove in
the wall (See Fig. 3-5-2(a)). For concealed installation, you may use 1＃PVC pipe
(See Fig. 3-5-2(b)).
3) Fig. 3-5-3 shall be followed no matter for open installation or for concealed installation.
Firstly, refer to the spacing of mounting holes (60mm) on the base panel of Wired
Controller and drill 2 holes (kept level) in the wall. Then, knock a wood plug into each
hole and fix the base panel of Wired Controller onto the wall. After that, insert the
communication wire into the control board. Finally, cover up the front panel of Wired
Controller.
Note:
When installing the base panel of Wired Controller, take special care on the direction of
base panel. The side with 2 notches must face downward; otherwise it will be impossible
to mount the Wired Controller panel correctly.
PVC管
PVC Pipe
1 2 3 4
(a) Open Installation of Cable (b) Concealed Installation of Cable

Fig. 3-5-2 Fig. 3-5-3 Installation Sketch
S/N Description
1 Wall
2 Base Panel of Wired Controller
3 Screw M4X10
4 Front Panel of Wired Controller
3.5.3 Connection of Electric Wire to Terminal Board See Fig. 3-5-4。

1) Before installing the electrical equipment, please take care on the following:
a) Check if the power supply is identical to the ratings on nameplate.
b) The power capacity shall be high enough and the section area of the cables in
the room shall be over 2.5mm2.
c) The cable must be installed by professional technicians.
d) The permanent circuit must be installed with leakage protection switch and air
switch with electrode contacts spaced over 3mm.
2) Connect the single wire
a) Use a wire stripper to remove the insulation layer for about 25mm at the end of
the single wire.
b) Remove the screws from the terminal board of air conditioner.
c) Use pliers to bend the end of single wire to a round ring conforming to the screw
size.
d) Insert the screw through the round ring of single wire and fix onto the terminal
board.
3) Connect the stranded wire
a) Use a wire stripper to remove the insulation layer for about 10mm at the end of
the stranded wire.
b) Remove the screws from the terminal board of air conditioner.
c) Use crimping pliers to clamp the end of stranded wire and make a terminal
conforming to the screw size.
d) Insert the screw through the terminal of stranded wire and fix onto the terminal
board.
A.单支线
Single-cord wire B.多股绞合线
Stranded wire
接线端子
Terminal
25
10
绝缘层Layer
Insulation
Fig. 3-5-4
Notes:
a) If the power cord or signal wire is damaged, be sure to replace with special cord.
b) Please identify the voltage indicated on the nameplate before starting cable
connection according to the wiring diagram.
c) The air conditioner shall be provided with special power cable and equipped with
leakage switch and air switch to respond to any overloading.
d) The air conditioner must be properly earthed to avoid the harm caused by
insulation failure.
e) All wires must be connected via press terminal or single wire. Direct connection
of stranded wire to the terminal board may cause spark.
f) All cables shall be correctly connected in accordance with the wiring diagram.
Wrong connection may cause malfunction or damage to the air conditioner.
g) Prevent the cables from contacting the refrigerant pipe, compressor, fan or other
moving parts.
h) Do not change the cable connection inside the air conditioner. The manufacturer
is not liable for any loss or abnormal operation thus arising.
3.5.4 Connection of Power Cable
1) For air conditioner using 1-phase supply:
a) Remove the front side plate of outdoor unit.
b) Open the cable-cross hole of outdoor unit and mount a rubber ring.
c) Insert the cable through rubber ring.
d) Connect the power cable to “L”, “N” terminals and earth screw.
e) Fix the cable with tie strap.
2) For air conditioner using 3-phase supply:
a) Remove the front side plate of outdoor unit.
b) Open the cable-cross hole of outdoor unit and mount a rubber ring.
c) Insert the cable through rubber ring.
d) Connect the power cable to “L1”, “L2”, “L3”, “N” terminals and earth screw.
e) Fix the cable securely with cable clamp.
Notes: For the air conditioner with auxiliary electric heater, the power cable shall also be
connected to “L1” , “L2”, “L3”, “N” terminals and earth screw in the electric box of indoor
unit.
3.5.5 Connection of Wired Controller Signal Wire
1) Open the electric box of indoor unit.
2) Insert the Wired Controller signal wire through the rubber ring.
3) Insert the Wired Controller signal wire into the 4-bit seat.
4) Fix the signal wire of Wired Controller tightly with tie strap.
Notes:
a) To prevent the air conditioner from malfunction due to electromagnetic
interference, be sure to take special care when performing the cable connection
below.
b) The signal wire of Wired Controller shall be separated from power cable and
indoor/outdoor connection cable.
c) If the air conditioner is installed at a place subject to electromagnetic interference,
it is best to use the shield wire and twisted pair as the signal wire of Wired
Controller.
3.5.6 Cable Connection
1) Remove the right side plate of outdoor unit and open the cable-cross hole. Install the
cable-cross loop.
2) Remove the cable clamp. Connect the power cable to the terminals and fix.
3) Use wire clamp to fix the power cable and signal control wire. Then, connect
correctly.
4) Check if the cable is properly fixed.
5) Reinstall the front side plate.
3.5.7 Drainage of Outdoor Condensate Water (No for cooling-only unit)
When the air conditioner is working under HEAT mode, the condensate water generated
by the outdoor unit and the defrosting water during defrosting mode operation will be
drained to a proper place via drainage pipe.
How to Install: Clamp the outdoor drainage connector to φ25 hole on the base, as shown
in Fig. 3-5-5. Then, connect the drainage pipe to drainage nozzle, so that the condensate
water and defrosting water can be drained to an appropriate place.
室外机底板
Outdoor Base Plate
室外机接头
Outdoor Connector
Fig. 3-5-5
3.5.8 Precautions on Installation
1. Follow the illustrated requirements to ensure there is enough space and good
ventilation for operation, repair and maintenance of the unit.
2. Drainage ditch shall be provided on the ground of outdoor unit.
3. To meet the restrictions of noise and vibration, the outdoor unit shall be installed with
rubber damping cushion, spring damper or rubber connector.
4. The beam and frame to lift the indoor unit shall be able to support 4 times the weight.
The bolts, caps and other fasteners shall be subjected to antirust treatment. Soft
connector shall be added at the connection of duct, thus to reduce the vibration.
5. The duct shall be designed in reference to data provided in the data sheet and the
computation method described in Part 1 of this manual. Heat insulation and sound
insulation shall be provided. It is recommended to use air flow regulation valve to
adjust the air flow at different positions of the air outlet system, making the unit run
under optimum state.
6. Be sure to lift the indoor and outdoor unit by using the designated lifting holes. During
lift, take care to protect the unit and avoid knocking the plates, thus to prevent possible
rusting in the future.
7. INVENTOR will not provide the copper tube, power cable and signal wire. Please
prepare according to technical parameters, and connect the pipe, power supply and
circuits correctly.
8. The unit must be tested by professional technicians or the user’s people with air
conditioner knowledge under the instructions of INVENTOR’s professional
technicians.
9. Before installing the indoor and outdoor connecting pipe, do not remove the plug
sealing the pipe.
10. To prevent dust or moisture entering into the system, connect the pipe quickly after
removing the seal plug.
11. The pipe must be installed in a wall-cross tube when passing the wall.
12. The shorter the connecting pipe is, the better. The smaller the height difference
between indoor unit and outdoor unit is, the better. The fewer the pipe bends, the
better. The bending radius shall be as large as possible.
13. When laying the pipes along the designated route, do not flatten the pipe. The
bending radius must be over 200MM. The connecting pipe shall not frequently bent or
stretched; otherwise it will become hardened. One pipe shall not be bent at the same
position over 3 times the maximum.
3.5.9 Precautions on Installation of Indoor Condensate Pipe
It is usually found that the condensate water of duct type air conditioner cannot be drained
out. Through our investigation and analysis, it is because the relative high-speed air flow
generated under negative pressure inside the unit that disturbs the normal drain of
condensate water. Therefore, we need to install a section of water seal at the drainage
outlet.
As shown in Fig. 3-5-6, the height of water seal depends on the pressure inside the
section where the condensate pipe is located.
P
When the section of condensate pipe is under negative pressure, h=x≥ 10 +20(mm)
When the section of condensate pipe is under positive pressure, x ≥ 30mm ， h ≥

P
10 +20(mm)
In which: P – Absolute pressure of this section inside the equipment, Pa。
Unit
To condensate pipe
Fig. 3-5-6 Indoor Water Seal Sketch
Note: 1. “h” shall be less than 50mm the minimum.
2. The condensate pipe shall be heat insulated.
3. The condensate pipe shall be kept an inclination 5～10° for easier drain of
the condensate water. To avoid condensing dew, the connector of
condensate pipe shall be heat insulated.

4. Please test the drainage system after completing the installation works.
During test, check if the water flows through the pipe correctly. Check the
connecting point with care to ensure there is no leakage. If the unit is
installed in a new house, it is recommended to test before starting decoration
of the ceiling.
3.5.10 Trial Run and Checks after Installation
Trial Run
1) Preparations for Trial Run
a) Do not connect to the power supply unless all installation works has been
completed.
b) The control circuit is correctly connected and all cables are fixed securely.
c) The valve of gas pipe and liquid pipe shall be open.
d) All scattered articles, especially the metal scraps and threads, shall be removed
from the unit.
2) Method of Trial Run
a) Switch on the power and press the ON/OFF button on the remote controller to
start the test run.
b) Press MODE button and select COOL, HEAT and FAN mode to check if the run
is normal.
c) Emergency run.
Checks after Installation See Table 3-4
Table 3-4
Possible Result in Case of Improper

Items to be Checked
Installation
If the installation is secure? The unit may fall, vibrate or give out noise
Possibly causing low cooling capacity (heating

If the leakage detection is done?
capacity).
If the unit is heat insulated satisfactorily? Possible dew or drips of water
If the water drainage is smooth? Possible dew or drips of water

The machine may be incurred to failure or the parts
If the power voltage is identical to the ratings on nameplate?
may be burnt
If the cables and pipes are connected correctly?
may be burnt
If the unit is safely earthed? Risk of electric leakage
If the cable type conforms to the specification?
may be burnt
Possibly causing low cooling capacity (heating
If there is obstacles at the air inlet and outlet of indoor and outdoor unit?
capacity).
If the refrigerant pipe length and refrigerant fill are recorded? Unable to control the quantity of refrigerant filled
3.6 Electric Installation
Working environment of electrical devices:
☆Be sure the electric supply that user applies is beyond the bounds of tolerances
(+/-10%, +/-1Hz).
☆The ambient temperature should be at 5-40°C ,and the humidity be at 30-95% .
☆Transport/storage temperature should be at -25-55°C and for short period not
exceeding 24h at up to +70°C.
☆ The installation altitude beyond the hight of 1000m.
Cautions on Electric Installation:
Caution: Before installing the electrical equipment, please pay attention to the
following matters which have been specially pointed out by our
designers:
（1） Check to see if the power supply used conforms to the rated power supply
specified on the nameplate.
（2） The capacity of the power supply must be large enough. The section area of
fitting line in the room shall be larger than 2.5mm2.
（3） The lines must be installed by professional personnel.
An electricity leakage protection switch and an air switch with gap between electrode
heads larger than 3 mm shall be installed in the fixed line.
1. Connection of single wire
（2） Use wire stripper to strip the insulation layer (25mm long) from the end of the
single wire.
（3） Remove the screw at the terminal board of the air-conditioning unit.
（4） User pliers to bend the end of the single wire so that a loop matching the
screw size is formed.
（5） Put the screw through the loop of the single wire and fix the loop at the
terminal board.
2.Connection of multiple twisted wires
（1） Use wire stripper to strip the insulation layer (10mm long) from the end of the
multiple twisted wires.
（2） Remove the screw at the terminal board of the air-conditioning unit.
（3） Use crimping pliers to connect a terminal (matching the size of the screw) at
the end of the multiple twisted wires.
（4） Put the screw through the terminal of the multiple twisted wires and fix the
terminal at the terminal board.
Warning:
If the power supply flexible line or the signal line of the equipment is damaged, only
use special flexible line to replace it.
1. Before connecting lines, read the voltages of the relevant parts on the
nameplate. Then carry out line connection according to the schematic
diagram.
2. The air-conditioning unit shall have special power supply line which
shall be equipped with electricity leakage switch and air switch, so as to
deal with overload conditions.
3. The air-conditioning unit must have grounding to avoid hazard owing to
insulation failure.
4. All fitting lines must use crimp terminals or single wire. If multiple
twisted wires are connected to terminal board, arc may arise.
5. All line connections must conform to the schematic diagram of lines.
Wrong connection may cause abnormal operation or damage of the
air-conditioning unit.
6. Do not let any cable contact the refrigerant pipe, the compressor and
moving parts such as fan.
Do not change the internal line connections inside the air-conditioning
unit. The manufacturer shall not be liable for any loss or abnormal
operation arising from wrong line connections.
7. shall not be liable for any loss or abnormal operation arising from wrong
line connections.
H.Power Cord Connection Caution:
For air-conditioner with auxiliary
1. Air-conditioning unit with single-phase power supply heater, it is required to connect the
power cable to the “L1, L2 L3
(1) Remove the front-side panel of the outdoor unit.
“ terminals and the grounding screw.
(2) Pass the cable though rubber ring.
(3) Connect the power supply cable to the “L, N” terminals and
the grounding screw.
(4) Use cable fastener to bundle and fix the cable.

Caution:
2. Air-conditioning unit with 3-phase power supply Take great care when carrying out the
following connections, so as to avoid
(1) Remove the front-side panel of the outdoor unit.
malfunction of the air-conditioning unit
(2) Attach rubber ring to the cable-cross hole of the because of electromagnetic interference.
(1) The signal line of the wire controller must
outdoor unit. be separated from the power line and the
(3) Pass the cable though rubber ring. connecting line between the indoor unit and
the outdoor unit.
(4) Connect the power cable to the terminal and earthing
(2) In case the unit is installed in a place
screws marked “L1, L2, L3 & N”. vulnerable by electromagnetic interference, it
is better to use shielded cable or
(5) Use cable fastener to bundle and fix the cable.
double-twisted cable as the signal line of the
I.Connection of Signal Line of Wire Controller wire controller.
1. Open the cover of the electric box of the indoor unit.
2. Pull the signal cable of the wire controller through the rubber ring.
3. Plug the signal line of the wire controller onto the 4-bit pin socket at the circuit board
of the indoor unit.
4. Use cable fastener to bundle and fix the signal cable of the wire controller.
● Products Electric Installation
Wiring layout
☆Installation should be conducted by National Wiring Regulation.
☆The rated voltage and exclusive power supply must be adopted for the air conditioners.
☆ The power cable should be reliable and fixed, in order to avoid the wiring terminal be
suffered from force. And do not drag the power cable forcibly.
☆ The wire diameter of power cable should be large enough, if power cable and
connection wire
be damaged, it should be replaced by the exclusive cable.
☆All electric installation must be done by professional personnel according to local law,
regulation and this manual.
☆It should be reliably earthed, and it should be connected to the special earth device, the
installation work should be operated by the professional.
☆The creepage protect switch and air switch must be installed.
Air switch should have the thermal dropout and magnetic dropout function, in order to
avoid the short circuit and overload.
☆ The on spot connection should refer to the circuit diagram, which is stuck on the unit
body.
Below is the recommended air switch capacity for related power cable diameters (For the
diameter of power cables for each unit, please see the attached instruction manual).
Dia. Of
Dia. Of Power Air Switch Capacity Air Switch Capacity
Power
Cable (A) (A)
Cable
2.5mm2 16A 4 mm2 20A
2 2
6 mm 25A;32A 10 mm 40A
2 2
16 mm 50A 25mm 63A
Condition for model selection above: The specification of power cable refers to the
specification of the BV single-cord cable (2 – 4 pcs) is paved in plastic pipe and used
under an ambient temperature of 40℃. The air switch is used under 40℃ and the type
of air switch is “D”. In case of any change in the actual installation conditions on site,
please follow the specifications of power cables and air switch provided by the
manufacturer and use for reduced capacity.
● Requirement for ground
☆ Air conditioner is the I class electric appliance, thus please do conduct reliable
grounding measure.
☆ The yellow-green two-color wiring of air conditioner is grounding wire and can not be
used for other purposes. It cannot be cut off and be fixed by screw, otherwise it would
cause electric shock.
☆ The user must offer the reliable grounding terminal. Please don’t connect the
grounding wire
to the following places:
① Water pipe；
② Gas pipe；
③ Blowing pipe；
④ Other places that professional personnel consider them unreliable.
Power Supply to Indoor and Outdoor Unit:
The power cable, communication wire connection between indoor and
outdoor
The power distribution for complete unit is as follows. The actual connection of earthing
wires shall be based on the circuit diagram attached on each unit.
Single-phase Outdoor Unit:
Three-phase Outdoor Unit: 5
Circuit Diagram:
Outdoor Unit:
URS-09¬ (Compatible with 09-18 Ceiling-seated and Duct Type Unit and 18 Well Type Unit):
URS-24 (Compatible with 24 Ceiling-seated and Duct Type Unit and Well Type Unit):
URS-36~50 (Compatible with 36-48 Ceiling-seated and Duct Type Unit and Well Type Unit):
URT-36~60 (Compatible with 36-60 Ceiling-seated and Duct Type Unit and Well Type Unit):
Indoor Unit:
Duct Type Indoor Unit:
VDI-09～60 (Except 18):
VDI-18
Well Type Indoor Unit:

URS-18 ～URT-60 ：
Ceiling-seated Indoor Unit:
VKI-09～60
4 Power Distribution of Unit

Using the unit with the most complete function as the example, the power distribution is as
follows:
Note: The bold line indicates the main circuit and the fine line indicates the control circuit.
The element on actual model shall be based on the actual circuit diagram.

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AI

3.1 Microcomputer Control System SeeTable 1-1

Control Function Protection Function Display Functions

over indoor temperature.)

switch in any sub-room.)

been stopped for a period of time.)

★ Weekly Timer and Centralized Control Function

Loc. No Loc. No Loc. No Loc. No

Display board Display board

Tel line base Tel line base Tel line base

4.1 Nominal Condition and Working Temp Range Table 4-1

4.2 Specifications and Technical Parameters Table

URS-09 URS-12 URS-18 URS-24

Cooling running: There is the same condition indoors and outdoors.

pressure (absolute value) (bar)

(a) Cooling operation (b) Heating operation

Indoor Relative Humidity (50%)

Indoor Wet Bulb (℃)

Indoor Wet Bulb (℃)

(a) Cooling Characteristics (b) Heating Characteristics

Liquid pipe diameter (mm)

Refrigerant charge volume (x150g)

5.4 Relationship between Air Flow and Static Pressure

(a) URS-24 and VDI-24 URS-24 and VDI-24

-20 0 20 40 60 80 100 120 140 160 180 200

6.1 Sketch of Structure of Unit

(a) 09～18kBtu indoor unit (b) 24～60kBtu indoor unit

Fig. 4-2 Outdoor Unit

Note: 5——Air inlet 6——Air outlet

(a) VDI-09 and VDI-12

788 ф12 ф22

Fig. 5-1 Outline and Dimesion of Indoor Unit

the help of fan motor.

Working Principle of the Unit:

Flow direction during cooling

Flow direction during heating

Indoor Unit Outdoor Unit

(a) Working principle of cooling only unit

Flow direction during heating

3-way Valve (gas valve)

Connection pipe One-way Valve

(b) Working principle of heat pump unit

3.1 User Guideline for Wired Controller

Component of Wired Controller

1 TIMER display 10 SLEEP mode display

 With each press of FAN button, the fan speed will

 Under DRY mode, the fan speed will be

▼:For decreasing temperature setting

 Under “COOL” mode, the COOL display will be

6) Timer Setting (Fig. 7)

8) Energy-saving Setting (Fig. 9)

and auto mode will be shielded.

10 seconds after display of outdoor environment

10) Memory Function Setting (Fig. 11)

11) Debugging Function (Fig. 12)

a）Setting of environment temp. sensor

Use “▲” or “▼” to adjust the display. When the first

13) Fault Display (Fig. 15)

Fig. 14 Remote Controller