38MBR

Outdoor Unit Single Zone Ductless System

Sizes 36 to 58

Service Manual
TABLE of CONTENTS These words are used with the safety-alert symbol. DANGER
identifies the most serious hazards which will result in severe personal
PAGE injury or death. WARNING signifies hazards which could result in
SAFETY CONSIDERATIONS ....................................................... 1 personal injury or death. CAUTION is used to identify unsafe
INTRODUCTION............................................................................ 1 practices which may result in minor personal injury or product and
property damage. NOTE is used to highlight suggestions which will
MODEL / SERIAL NUMBER NOMENCLATURES .................... 2 result in enhanced installation, reliability, or operation.
SPECIFICATIONS .......................................................................... 3
DIMENSIONS ................................................................................. 4
CLEARANCES................................................................................ 6
ELECTRICAL DATA ..................................................................... 7
WARNING
WIRING ........................................................................................... 7
ELECTRICAL SHOCK HAZARD
CONNECTION DIAGRAM............................................................ 7
Failure to follow this warning could result in personal injury or death.
WIRING DIAGRAMS..................................................................... 8 Before installing, modifying, or servicing system, main electrical
FAN AND MOTOR SPECIFICATIONS ........................................ 12 disconnect switch must be in the OFF position. There may be more than 1
disconnect switch.
REFRIGERATION CYCLE DIAGRAM........................................ 12
Lock out and tag switch with a suitable warning label.
REFRIGERANT LINES .................................................................. 13
SYSTEM EVACUATION AND CHARGING ............................... 14
SYSTEM VACUUM AND CHARGE ............................................ 14
ELECTRONIC FUNCTIONS ......................................................... 15
POINT CHECK FUNCTION .......................................................... 18
WARNING
TROUBLESHOOTING ................................................................... 20
DIAGNOSTIC GUIDES.................................................................. 21 EXPLOSION HAZARD
Failure to follow this warning could result in
DIAGNOSIS AND SOLUTION...................................................... 22 death, serious personal injury, and/or property
DISASSEMBLY INSTRUCTIONS SIZE 36.................................. 51 damage. Never use air or gases containing oxygen
DISASSEMBLY INSTRUCTIONS SIZE 48-58 ............................ 57 for leak testing or operating refrigerant
compressors. Pressurized mixtures of air or gases
containing oxygen can lead to an explosion.

SAFETY CONSIDERATIONS
Installing, starting up, and servicing air-conditioning equipment can
be hazardous due to system pressures, electrical components, and
CAUTION
equipment location (roofs, elevated structures, etc.).
Only trained, qualified installers and service mechanics should install, EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage or improper
start-up, and service this equipment.
operation.
Untrained personnel can perform basic maintenance functions such as Do not bury more than 36 in. (914 mm) of refrigerant pipe in the ground.
coil cleaning. All other operations should be performed by trained If any section of pipe is buried, there must be a 6 in. (152 mm) vertical rise
service personnel. to the valve connections on the outdoor units. If more than the
When working on the equipment, observe precautions in the literature recommended length is buried, refrigerant may migrate to the cooler
and on tags, stickers, and labels attached to the equipment. buried section during extended periods of system shutdown. This causes
Follow all safety codes. Wear safety glasses and work gloves. Keep a refrigerant slugging and could possibly damage the compressor at start-up.
quenching cloth and fire extinguisher nearby when brazing. Use care
in handling, rigging, and setting bulky equipment. INTRODUCTION
Read this manual thoroughly and follow all warnings or cautions
This service manual provides the necessary information to service,
included in the literature and attached to the unit. Consult local repair, and maintain the 38MBR family of heat pumps. Section 2 of
building codes and National Electrical Code (NEC) for special this manual has an appendix with data required to perform
requirements. Recognize safety information. This is the safety-alert troubleshooting. Use the “TABLE of CONTENTS” on page 1 to
symbol . When you see this symbol on the unit and in instructions locate a desired topic.
or manuals, be alert to the potential for personal injury. Understand
these signal words: DANGER, WARNING, and CAUTION.
MODEL / SERIAL NUMBER NOMENCLATURES
Table 1 —Unit Sizes
SYSTEM TONS kBTUh VOLTAGE-PHASE OUTDOOR MODEL
3.00 36,000 208/230-1 38MBRQ36A--3
4.00 48,000 208/230-1 38MBRQ48A--3
5.00 58,000 208/230-1 38MBRQ58A--3

OUTDOOR UNIT
38 MB R Q 36 A -- 3

38 = OUTDOOR UNIT

VOLTAGE
MB = MODEL 3 = 208/230-1-60

UNIT TYPE NOT USED

R = OUTDOOR UNIT

SYSTEM TYPE
Q = HEAT PUMP

NOMINAL CAPACITY
MAXIMUM NUMBER OF FAN COIL UNITS THAT
36 - 3 TONS
CAN BE CONNECTED TO THE OUTDOOR UNIT
48 - 4 TONS
A = 1:1
58 - 5 TONS

01 19 V 10001

Week of Manufacture Sequential Serial Number

Year of Manufacture V = ALL MODELS

Use of the AHRI Certified

TM Mark indicates a
manufacturer’s
participation in the
program For verification
of certification for individual
products, go to
www.ahridirectory.org.

2 Specifications subject to change without notice. 38MBR-03SM

SPECIFICATIONS
Table 2 — Specifications
HEAT PUMP
Size 36 48 58
SYSTEM
Outdoor Model 38MBRQ36A--3 38MBRQ48A--3 38MBRQ58A--3
Voltage, Phase, Cycle V/Ph/Hz 208/230-1-60 208/230-1-60 208/230-1-60
ELECTRICAL MCA A. 30 35 35
MOCP-Fuse Rating A. 50 50 50
OPERATING Cooling Outdoor DB Min - Max °F (°C) -13~122 (-25~50) -13~122 (-25~50) -13~122 (-25~50)
RANGE Heating Outdoor DB Min - Max °F (°C) -22~86 (-30~30) -22~86 (-30~30) -22~86 (-30~30)
Total Piping Length ft (m) 213 (65) 213 (65) 213 (65)
Piping Lift* ft (m) 98 (30) 98 (30) 98 (30)
PIPING
Pipe Connection Size - Liquid in (mm) 3/8 (9.52) 3/8 (9.52) 3/8 (9.52)
Pipe Connection Size - Suction in (mm) 5/8 (16) 5/8 (16) 3/4 (19)
Type R410A R410A R410A
REFRIGERANT Charge lbs (kg) 6.72 (3.05) 9.26 (4.2) 10.19 (4.62)
Metering Device EEV EEV EEV
Face Area Sq. Ft. 8.0 13.6 13.3
No. Rows 2 2 3
OUTDOOR COIL
Fins per inch 18 18 18
Circuits 4 8 14
Type Rotary Inverter Rotary Inverter Rotary Inverter
Model ATF310D43UMT ATQ420D1UMU ATQ420D1UMU
COMPRESSOR Oil Type ESTER OIL VG74 ESTER OIL VG74 ESTER OIL VG74
Oil Charge Fl. Oz. 28.2 39.5 39.5
Rated Circuit RLA 8.9 11.9 11.9
Unit Width in (mm) 37.24 (946) 37.48 (952) 37.48 (952)
Unit Height in (mm) 31.89 (810) 52.48 (1333) 52.48 (1333)
Unit Depth in (mm) 16.14 (410) 16.34 (415) 16.34 (415)
OUTDOOR
Net Weight lbs (kg) 148.59 (67.4) 217.4 (98.6) 225.09 (102.1)
Airflow CFM 2,130 4,500 4,415
Sound Pressure dB(A) 63.0 62.5 64.0
* Condensing unit above or below the indoor unit.

38MBR-03SM Specifications subject to change without notice. 3

DIMENSIONS

L1

L2
Fig. 1 — Size 36K

Table 3 — Dimensions
OPERATING
UNIT SIZE WIDTH in (mm) DEPTH in (mm) HEIGHT in (mm) L1 in (mm) L2 in (mm) WEIGHT
36K 37.24 (946) 16.14 (410) 31.89 (810) 26.50 (673) 15.87 (403) 136.47 (61.9)

4 Specifications subject to change without notice. 38MBR-03SM

DIMENSIONS (CONT)

Fig. 2 — Sizes 48K-58K

Table 4 — Dimensions
OPERATING
UNIT SIZE WIDTH in (mm) DEPTH in (mm) HEIGHT in (mm) L1 in (mm) L2 in (mm) WEIGHT
48K 37.22 (945) 15.58 (396) 52.48 (1333) 24.96 (634) 15.90 (404) 217.4 (98.6)
58K 37.22 (945) 15.58 (396) 52.48 (1333) 24.96 (634) 15.90 (404) 225.09 (102.1)

38MBR-03SM Specifications subject to change without notice. 5

CLEARANCES

A
Air-inlet

D B C

Air-outlet

Fig. 3 — Unit Clearance

Table 5 — Unit Clearance

MINIMUM VALUE
UNIT in. (mm)
A 24 (610)
B 24 (610)
C 24 (610)
D 4 (101)
E 4 (101)
NOTE: The outdoor unit must be mounted at least 2 in. (50mm) above the maximum anticipated snow depth.

19in (48cm) or more

on a multiple parallel
9.8 in (25cm) unit arrangement
or more for 4in (10cm) or more
proper airflow on a single parallel
24in(61cm) or unit arrangement
more
recommended
for service
118in (300cm)
9.8 in (25cm) or more
or more for
proper airflow
24in(61cm) or
more
recommended
for service

59in (150cm) 24in (60cm)

or more on a or more
multiple parallel
unit arrangement
24in (61cm) or more
on a single parallel
unit arrangement

Fig. 4 — Clearances for multiple units

6 Specifications subject to change without notice. 38MBR-03SM

ELECTRICAL DATA
Table 6 — Single Zone Outdoor Unit
OUTDOOR UNIT SIZE 36K 48K 58K
Volts-PH-Hz 208/230-1-60 208/230-1-60 208/230-1-60
Max – Min* Oper. Voltage 253-187 253-187 253-187
POWER SUPPLY
MCA 30 35 35
Max Fuse/CB AMP 50 50 50
Volts-PH-Hz 208/230-1-60 208/230-1-60 208/230-1-60
COMPRESSOR
RLA 8.85 11.86 11.86
*Permissible limits of the voltage range at which the unit will operate satisfactorily.
LEGEND
• FLA - Full Load Amps
• MCA - Minimum Circuit Amps
• RLA - Rated Load Amps

WIRING
All wires must be sized per NEC (National Electrical Code) or CEC
(Canadian Electrical Code) and local codes. Use Electrical Data table
CAUTION
MCA (minimum circuit amps) and MOCP (maximum over current
protection) to correctly size the wires and the disconnect fuse or
breakers respectively. EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
Sizes 36-58 Recommended Connection Method for Power
and Communication Wiring or improper operation.
Wires should be sized based on NEC and local codes.
Power and Communication Wiring:
The main power is supplied to the outdoor unit. The field supplied
power wiring from the outdoor unit to the indoor unit consists of three
(3) wires and provides the power for the indoor unit. Two wires are
CAUTION
high voltage AC power and one is a ground wire. To minimize voltage
drop, the factory recommended wire size is 14/2 stranded with a
ground. EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
Communication Wiring: or improper operation.
Be sure to comply with local codes while running wire from
A separate shielded stranded copper conductor only, with a 600 volt
rating and double insulated copper wire, must be used as the the indoor unit to the outdoor unit.
communication wire from the outdoor unit to the indoor unit. Please Every wire must be connected firmly. Loose wiring may
use a separate shielded 16GA stranded control wire. cause the terminal to overheat or result in unit malfunction. A
fire hazard may also exist. Ensure all wiring is tightly
connected.
No wire should touch the refrigerant tubing, compressor or
any moving parts.
Disconnecting means must be provided and shall be located
within sight and readily accessible from the air conditioner.
Connecting cable with conduit shall be routed through the
hole in the conduit panel.

CONNECTION DIAGRAM

Fig. 5 — Connection Diagram

NOTES:
1. Do not use thermostat wire for any connection between indoor and outdoor units.
2. All connections between indoor and outdoor units must be as shown. The connections are sensitive to polarity and will generate a fault code.

38MBR-03SM Specifications subject to change without notice. 7

WIRING DIAGRAMS
Size 36K

L-PRO

H-PRO
Applicable to the units
W BLACK

T4

T3

TP
COMP V RED adopting DC motor only
U
BLUE 3
FM1
Y/G
Y/G

CN43 CN41 CN9 CN8 CN33 EEV

CN19
DRIVER BOARD

5
U

4-WAY1 SV CN20 M
BLUE CN3 CN42
BLUE
P-1
CN55

7 CN22
BLUE BLUE
V

RED CN4 Y/G

OPTIONAL

BLACK CN40
MAIN BOARD
CN53

HEAT_Y RED CN10

W

CN44 CN2
BLACK
HEAT_D
CN51

CN52

CN54

7 CN7

CN5 CN1
BLACK

CN6 CN34
RED
BLUE

BLUE

RED

BLACK
BLACK
OPTIONAL

RED
YELLOW
YELLOW

YELLOW

GRAY

L
XT2 S1 S2 (1)L1 (2)L2 L1 L2 XT1

OPTIONAL

TO INDOOR COMM. BUS

NOTE Please use 2-core TO INDOOR UNIT MAIN POWER
shielded wire. POWER SUPPLY SUPPLY

Fig. 6 — Wiring Diagram Size 36K

Table 7 — Wiring Diagram Size 36K Codes

CODE PART NAME
CN1~CN2 Input: 230VAC High voltage
CN5~CN6 Output: 230VAC High voltage
P-1 Connection to the earth
CN10~CN44 Output: 230VAC High voltage Chassis Crankcase Heater
CN4~CN40 Output: 230VAC High voltage Compressor Crankcase Heat
CN3~CN22 Output: 230VAC High voltage
CN43 Output: Pin3~Pin2, Pin4~Pin2 (230 VAC High voltage) For AC FAN
CN41~CN42 Output To AC FAN Capacitor
CN34 Output:-24VDC-24VDC
CN33 Input: Pin 1 (0-5VDC),Pin 2 (5VDC) Discharge Temperature Sensor
CN8 Input: Pin3, Pin4 (5VDC),Pin2 (0VDC),Pin1,Pin5 (0-5VDC) T3 & T4
CN9 Input: Pin2, Pin4 (0VDC),Pin1,Pin3 (0-5VDC) H/L Pressure Switch
CN20 Output: Pin1-Pin4: Pulse waveform(0-12VDC),Pin5, Pin6 (12VDC)
CN7 Output: Pin1 (12VDC),Pin2 (5VDC),Pin3 (EARTH)

8 Specifications subject to change without notice. 38MBR-03SM

WIRING DIAGRAMS (CONT)
Size 36K

Table 8 — Wiring Diagram Size 36K Codes

OUTDOOR UNIT PFC & IPM BOARD
CODE PART NAME
CN53~CN54 Input: 230VAC High voltage
CN55 Output: Pin1 (12VDC),Pin2 (5VDC),Pin3 (EARTH)
CN19 Pin1~Pin3: Connect to FAN voltage among phases 0~200VAC
U~V~W Connect to compressor voltage among phases 0~200VAC
CN51~CN52 CN51~EARTH,CN52~EARTH Output: 224-380VDC High voltage

Table 9 — Wiring Diagram Sizes 09K, 12K, 18K (208-230V)

CODE PART NAME CODE PART NAME
COMP COMPRESSOR L PFC INDUCTOR
CAP1 FAN MOTOR CAPACITOR L-PRO LOW PRESSURE SWITCH
HEAT CRANKCASE HEATING H-PRO HIGH PRESSURE SWITCH
FM1 OUTDOOR DC FAN SV 4-WAY VALVE
FAN1 OUTDOOR AC FAN T3 CONDENSER TEMPERATURE SENSOR
EEV ELECTRONIC EXPANSION VALVE T4 OUTDOOR AMBIENT TEMPERATURE SENSOR

38MBR-03SM Specifications subject to change without notice. 9

WIRING DIAGRAMS (CONT)
Sizes 48K and 58K

Notes: WIRING DIAGRAM (OUTDOOR UNIT)

This symbol indicates the element
is optional, the actual shape prevails.
CH2

POWER SUPPLY
Ferrite bead D

XT1
RED BLACK

~
1
Ferrite bead
L P6 P5 Y/G

3 2
~ ~
CH2
YELLOW

CN4 BLACK

L1 L2
RED

L N
CN3

MAIN
BLACK

5
YELLOW

Ferrite bead CT1 CN1 WIHTE

/RED
CN2 XT2
Y/G

TO INDOOR UNIT
CN2 CN1 BLUE
MAIN BOARD /BLACK

(1)L1 (2)L2
(1)N (2)N
CN3 P7
CH1 CN6 U W P8 RED
BLUE V P9
RED OPTIONAL
BLACK CN22
Ferrite bead
V
U W CN20 OPTIONAL
COMP IPM & PFC BOARD BLACK HEAT_D
CN19 RED
FAN1 10 ORANGE
Y/G CN9 CN6 CN25
HEAT_Y
Ferrite bead

CH2 CN24
2 ORANGE OPTIONAL
Ferrite bead BLUE
CH2 3 CN18
4-WAY
CN17
CN1 CON1 BLUE SV
T3 T4
CN12 CN8 CN9
DC MOTOR
CN28
AMBIENT SENSOR

DRIVER BOARD 2

YELLOW
PIPE TEMP.SENSOR

TH PAIQI

GRAY
3 CN31
CN36
Y/G DCFAN2 3
DCFAN1 FAN1 FAN2
CN32 XT2 S1 S2
Y/G
CN27
A
CN15 CN10 CN34
Ferrite
bead
ELECTRONIC RED YELLOW
EXPANSIVE
VALVE A
H-PRO
L-PRO

TO INDOOR COMM. BUS

NOTE Please use 2-core
shielded wire.

Fig. 7 — Wiring Diagram Sizes 48K and 58K

Table 10 — Wiring Diagram Sizes 48K and 58K Codes

CODE PART NAME
CN1~CN3 Input: 230VAC High voltage
P7~P8 Output: 230VAC High voltage to IDU
P5,P6,P9 Connection to the earth
CN22 Output:-24VDC-24VDC for IDU Communication
CN17~CN18 Output: 230VAC High voltage 4 way valve
CN19~CN20 Output: 230VAC High voltage Chassis Crankcase Heater
CN24~CN25 Output: 230VAC High voltage Compressor Crankcase Heater
CN2~CN4 Output: 230VAC High voltage to AC CURRENT DETECTOR
CN12 Input: Pin1 (0-5VDC),Pin2 (5VDC) Heatsink Temperature Sensor
CN8 Input: Pin1 (0-5VDC),Pin2 (5VDC) Compressor Top Sensor (PAIQI)
CN9 Input: Pin3,Pin4 (5VDC),Pin2 (0VDC),Pin1,Pin5 (0-5VDC) the ambient sensor and pipe sensor
CN10 Input: Pin2, Pin4 (0VDC),Pin1,Pin3 (0-5VDC) for the H/L pressure switch
CN15 Output: Pin1-Pin4: Pulse waveform (0-12VDC),Pin5, Pin6 (12VDC) EEV
CN6 Output: Pin1-Pin6: Pulse waveform (0-5VDC), Pin7, Pin9 (0VDC) Pin8 (0-5VDC), Pin10 (5VDC)

10 Specifications subject to change without notice. 38MBR-03SM

WIRING DIAGRAMS (CONT)
Sizes 48K and 58K
Table 11 — Wiring Diagram Sizes 48K and 58K Codes
OUTDOOR UNIT PFC & IPM BOARD
CODE PART NAME
CN1~CN6 Output:224-380VDC High voltage to DIODE MODULE
CN2~CN3 Output:224-380VDC High voltage to PFC INDUCTOR
U~V~W Connection to compressor voltage among phases 0~200VAC
CN9 Input:Pin1-Pin6: Pulse waveform (0-5VDC),Pin7, Pin9 (0VDC) Pin8 (0-5VDC),Pin10 (5VDC)
FAN1 Output: Pin1~Pin2: High voltage (224-380VDC), Pin4 (0-15VDC) Pin5 (0-5.6VDC), Pin6:Pulse waveform (0-15VDC)

Table 12 — Wiring Diagram Sizes 48K and 58K Codes

OUTDOOR UNIT DC MOTOR DRIVER BOARD
CODE PART NAME
CON1 Output:Pin1~Pin2:High voltage (224-380VDC)
CN1 Input: Pin4: Pulse waveform (0-15VDC) ,Pin3 (0-6.5VDC) Pin2 (0VDC),Pin1 (15VDC)
FAN1 Pin1-Pin3: Connect to FAN voltage among phases 0~200VAC
FAN2 Pin1-Pin3: Connect to FAN voltage among phases 0~200VAC

Table 13 — Wiring Diagram Sizes 48K and 58K Codes

CODE PART NAME
COMP COMPRESSOR
CAP1,CAP2 FAN MOTOR CAPACITOR
CT1 AC CURRENT DETECTOR
D DIODE MODULE
EEV ELECTRONIC EXPANSION VALVE
FM1,FM2 OUTDOOR DC FAN
FAN1,FAN2 OUTDOOR AC FAN
HEAT CRANKCASE HEATING
H-PRO HIGH PRESSURE SWITCH
L PFC INDUCTOR
L-PRO LOW PRESSURE SWITCH
KM AC CONTACTOR
SV 4-WAY VALVE
TP EXHAUST TEMPERATURE SENSOR
T3 CONDENSER TEMPERATURE SENSOR
T4 OUTDOOR AMBIENT TEMPERATURE SENSOR
TH HEATSINK TEMPERATURE SENSOR
PAIQI COMPRESSOR TOP SENSOR (GAS PIPE SENSOR)
CH 1
CH 2 FERRITE BEAD
CH 3

38MBR-03SM Specifications subject to change without notice. 11

FAN AND MOTOR SPECIFICATIONS
Table 14 — Fan and Motor Specifications
System Size 36K 48K 58K
Material -- AS AS AS
Type -- ZL-560*139*12-3KN ZL-554*148*12-3KFN ZL-554*148*12-3KFN
Outdoor Fan Propeller
Diameter in (mm) 22.05 (560) 21.81 (554) 21.81 (554)
Height in (mm) 5.47 (139) 5.83 (148) 5.83 (148)
Model -- WZDK120-38G-W ZKFN-85-8-22 ZKFN-85-8-22
Type -- DC DC DC
Phase -- 1 1 1
FLA A 1.21 1.17 1.17
Insulation Class -- E E E
Safe Class -- IPX0 IPX0 IPX0
Input W 150 126 126
Outdoor Fan Motor Output A 120 85 85
Range of current A 1.21±10% 1.17±10% 1.17±10%
Rated current A 1.21 1.17 1.17
Capacitor μF N/A N/A N/A
Rated HP HP 0.16 0.14 0.14
Speed rev/min 850/800/750 900/850/750 900/850/750
Rated RPM rev/min 1050 900 900
Max. input W 150 126 126

REFRIGERATION CYCLE DIAGRAM

INDOOR OUTDOOR

Electronic
LIQUID SIDE CAPILIARY TUBE expansion valve

2-WAY VALVE T3 Condenser

temp. sensor

HEAT
EXCHANGE
(EVAPORATOR)

HEAT
T2 Evaporator T1 Room temp. T4 Ambient EXCHANGE
temp. sensor sensor temp. sensor (CONDENSER)
middle

T2B Evaporator
temp. sensor
outlet
GAS SIDE
4-WAY VALVE

3-WAY VALVE

T5 Discharge
temp. sensor
COOLING
Compressor
HEATING

Fig. 8 — Refrigerant Cycle Diagram

12 Specifications subject to change without notice. 38MBR-03SM

REFRIGERANT LINES
General Refrigerant Line Sizing
1. The outdoor units are shipped with a full charge of R410A refrigerant. All charges, line sizing, and capacities are based on runs of 25ft. (7.6 m).
For runs over 25 ft. (7.6 m), consult the long-line applications section for the proper charge adjustments.
2. The minimum refrigerant line length between the indoor and outdoor units is 10 ft. (3 m).
3. Refrigerant lines should not be buried in the ground. If it is necessary to bury the lines, not more than 36in (914 mm) should be buried. Provide a
minimum 6in (152 mm) vertical rise to the service valves to prevent refrigerant migration.
4. Both lines must be insulated. Use a minimum of 1/2in. (12.7 mm) thick insulation. Closed-cell insulation is recommended in all long-line
applications.
5. Special consideration should be given to isolating interconnecting tubing from the building structure. Isolate the tubing so vibration or noise is not
transmitted into the structure.

IMPORTANT: Both refrigerant lines must be insulated separately.

Table 15 displays the following maximum lengths allowed.

Table 15 — Piping and Refrigerant

System Size 36K 48K 58K
Min. Piping Length ft (m) 10(3) 10(3) 10(3)
Standard Piping Length ft (m) 25(7.5) 25(7.5) 25(7.5)
Max. outdoor-indoor height difference (OU higher than IU) ft (m) 98(30) 98(30) 98(30)
Max. outdoor-indoor height difference (IU higher than OU) ft (m) 98(30) 98(30) 98(30)
Max. Piping length with no additional refrigerant charge ft (m) 26(8) 26(8) 26(8)
PIPING
Max. Piping Length ft (m) 213(65) 213(65) 213(65)
Additional refrigerant charge
(between Standard - Line Lengths Max piping length) Oz/ft(g/m) 0.43(40) 0.43(40) 0.32(30)
Gas Pipe (size-connection type) in (mm) 5/8(16) 5/8(16) 3/4(19)
Liquid Pipe (size-connection type) in (mm) 3/8(9.52) 3/8(9.52) 3/8(9.52)
Refrigerant Type -- R410A R410A R410A
REFRIGERANT
Charge Amount Lbs (kg) 6.72(3.05) 9.26(4.2) 10.19(4.62)

• The charge amount listed in Table 15 is for piping runs up to 25 ft. (7.6 m).

• For piping runs greater than 25 ft. (7.6 m), add refrigerant up to the allowable length as specified in Table 16.

Long Line Applications,:

1. No change in line sizing is required.
2. Add refrigerant per Table 16.
Table 16 — Additional Charge Table Per Zone
TOTAL LINE LENGTH FT. ADDITIONAL CHARGE OZ/FT. (M)
UNIT SIZE >10-25 >25-213
MIN. MAX. (3-8) (8-65)
36
48 10 213 None 0.43
58

38MBR-03SM Specifications subject to change without notice. 13

SYSTEM EVACUATION AND CHARGING
Deep Vacuum Method

CAUTION The deep vacuum method requires a vacuum pump capable of pulling a
vacuum of 500 microns and a vacuum gage capable of accurately mea-
suring this vacuum depth. The deep vacuum method is the most positive
UNIT DAMAGE HAZARD way of assuring a system is free of air and liquid water (see Fig. 11).
Failure to follow this caution may result in equipment damage
or improper operation.
5000
Never use the system compressor as a vacuum pump. 4500
4000
Refrigerant tubes and indoor coil should be evacuated using the 3500 LEAK IN

MICRONS
SYSTEM
recommended deep vacuum method of 500 microns. The alternate 3000
triple evacuation method may be used if the following procedure is
followed. Always break a vacuum with dry nitrogen. 2500
2000
VACUUM TIGHT
SYSTEM VACUUM AND CHARGE 1500
1000
TOO WET
TIGHT
Using Vacuum Pump 500 DRY SYSTEM

1. Completely tighten the flare nuts (A, B, C, D, E). Fully open all 0 1 2 3 4 5 6 7
circuits service valves. Connect the manifold gage charge hose to MINUTES
the charge port of the low side Master service valve to evacuate all
circuits at the same time (see Fig. 9). Fig. 11 — Deep Vacuum Graph
2. Connect charge hose to vacuum pump.
3. Fully open the low side of manifold gage (see Fig. 10). Triple Evacuation Method
4. Start vacuum pump
5. Evacuate using the triple evacuation method. The triple evacuation method should be used. Refer to Fig. 12 and
proceed as follows:
6. After evacuation is complete, fully close the low side of manifold
gage and stop operation of vacuum pump. 1. Pump system down to 500 MICRONS of mercury and allow pump to
7. The factory charge contained in the outdoor unit is good for up continue operating for an additional 15 minutes. Unit must maintain
to 25ft. (8 m) of line length. For refrigerant lines longer than 500 microns or less for 30 minutes or more to ensure a dry system.
25ft. (8 m), add refrigerant as specified in “Additional Charge 2. Close service valves and shut off vacuum pump.
Table Per Zone” on page 13.
3. Connect a nitrogen cylinder and regulator to system and open until
8. Disconnect charge hose from charge connection of the low side system pressure is 2 psig.
service valve.
4. Close service valve and allow system to stand for 10 minutes.
9. Securely tighten caps of service valves. During this time, dry nitrogen will be able to diffuse throughout the
system absorbing moisture.
5. Repeat this procedure as indicated in Fig. 12. System will then be
Outdoor Unit Refrigerant Indoor Unit free of any contaminants and water vapor.
A Low Side C
D EVACUATE
B High Side
BREAK VACUUM WITH DRY NITROGEN
Service Valve
WAIT
Fig. 9 — Service Valve EVACUATE

BREAK VACUUM WITH DRY NITROGEN

Manifold Gage
WAIT

500 microns EVACUATE

Low side valve High side valve CHECK FOR TIGHT, DRY SYSTEM
(IF IT HOLDS DEEP VACUUM)
Charge hose Charge hose
RELEASE CHARGE INTO SYSTEM
Vacuum pump
Fig. 12 — Triple Evacuation Method

Final Tubing Check

Low side valve
IMPORTANT: IMPORTANT: Check to be certain factory
Fig. 10 — Manifold tubing on both indoor and outdoor unit has not shifted
during shipment. Ensure tubes are not rubbing against each
other or any sheet metal. Pay close attention to feeder tubes,
making sure wire ties on feeder tubes are secure and tight.

14 Specifications subject to change without notice. 38MBR-03SM

ELECTRONIC FUNCTIONS
Abbreviation Condenser High Temperature T3 Protection:
• T1: Indoor room temperature • 131°F(55°C)<T3<140°F(60°C), the compressor frequency
decreases to the lower level until to F1 and then runs at F1. If
• T2: Coil temperature of indoor heat exchanger middle T3<129.2°F(54°C), the compressor keeps running at the current
• T2B: Coil temperature of indoor heat exchanger outlet frequency.
• T3: Coil temperature of condenser • T3<125.6°F(52°C), the compressor does not limit the frequency
• T4: Outdoor ambient temperature and resumes the former frequency.
• T5: Compressor discharge temperature • T3>140°F(60°C) for 5 seconds, the compressor stops until
T3<125.6°F(52°C).
• Td: Target temperature
Evaporator Low Temperature T2 Protection:
Main Protection • T2<32°F(0°C), the compressor stops and restarts when
T2=41°F(5°C).
Three Minute Delay for Compressor Restart • 32°F(0°C)≦T2<39.2°F(4°C), the compressor frequency is limited
Less than a 1 minute delay for the initial start-up and a 3 minute delay and decreases to the lower level
for subsequent starts. • 39.2°F(4°C)=T2<44.6°F(7°C), the compressor retains the current
frequency
Compressor Top Temperature Protection • T2>44.6°F(7°C), the compressor frequency is not limited.
The unit stops working when the compressor top temp. protector cuts
off, and restarts after the compressor top temp. protector restarts. Operation Modes and Functions
Compressor Discharge Temperature Protection FAN Mode
When the compressor discharge temp. increases, the running 1. Outdoor fan and compressor stop
frequency is limited per the following rules: 2. Temperature setting function is disabled and no setting temperature
• Compressor discharge temp. T5>239°F(115°C) for 5s, compressor appears.
stops and restarts up until T5<194°F (90°C) 3. Indoor fan can be set to high/med/low/auto
• 110<T5<239°F(115°C), decrease the frequency to the lower level 4. The louver operates same as in the COOLING mode.
every 2 minutes. 5. Auto fan
• 221°F(105°C)<T5<230°F(110°C), keep running at the current
frequency.
• T5<221°F(105°C), no limit for frequency. T1
°C H
Fan Speed is Out of Control
When the indoor fan speed remains low (lower than 300RPM) for 50s, 10.8°F (6.0°C)
the indoor fan shuts off and restarts 30s later. If the protection mode a (H-L)*0.75+L
engages 3 times when the fan motor restarts continuously, the unit 9°F (5.0°C)
stops and the LED displays the failure. b (H-L)*0.5+L
When the outdoor fan speed remains low (lower than 100RPM) or too 7.2°F (4.0°C)
high (higher than 1500RPM) for 60s, the unit stops and the LED c (H-L)*0.25+L
displays the failure. The malfunction clears 30s later. 6°F (3.0°C)
d L
Inverter Module Protection 1.8°F (1.0°C)
e
The inverter module has a protection function for current, voltage and
temperature. If any of these protections engage, the corresponding Fig. 13 — FAN Mode
code displays on the indoor unit and the unit stops working.

Indoor Fan Delayed Open Function

When the unit starts up, the louver is active immediately and the
indoor fan opens 10s later. If the unit is running in the HEATING
mode, the indoor fan is controlled also by the anti-cold wind function.

Compressor Preheating Functions

Preheating Permitting Condition:
If T4<37.4°F(3°C) and the machine connects to power supply newly
within 5 seconds or if T4<37.4°F(3°C) and the compressor has
stopped for over 3 hours, the compressor heating cable will work.
Preheating Mode:
A weak current flow through the compressor coil from the compressor
wiring terminal, then the compressor is heated without operation.
Preheating Release Condition:
If T4=41°F(5°C) or the compressor starts running, the preheating
function stops.

38MBR-03SM Specifications subject to change without notice. 15

COOLING Mode HEATING Mode
Outdoor Fan Running Rules Outdoor Fan Running Rules

T4
A DC_FAN_HI_SPD_ADD
ADD
D
DD
28 (82.4°F) E DC_FAN_SSLOW_SPD_ADD
69.8°F(21°C)
26 (78.8°F)
66.2°F(19°C)
B DC_FAN_MID_SPD_ADD
_A
ADD
25 (77°F) D DC_FAN_SLOW_SPD_ADD
64.4°F(18°C)

23 (73.4°F) 60.8°F(16°C)
C DC_FAN_MIN_SPD_ADD
_ADD
DD
D C DC_FAN_MIN_SPD_ADD
22 (71.6°F) 59°F(15°C)

20 (69°F) 55.4°F(13°C)
D DC_FAN_SLOW_SPD_ADD
PD_A
ADD B DC_FAN_MID_SPD_ADD
19 (66.2°F) 53.6°F(12°C)

17 (62.6°F) 50°F(10°C)
E DC_FAN_SSLOW_SPD_ADD
SPD_A
ADD A DC_FAN_HI_SPD_ADD

Fig. 14 — Outdoor Fan Running Rules Fig. 17 — Outdoor Fan Running Rules
In the COOLING mode, the indoor fan runs all the time and the Indoor Fan Running Rules
speed can be selected as high, medium, low and auto. The indoor fan
is controlled as shown in Fig. 15. When the compressor is on, the indoor fan can be set to high/med/low/
auto. And the anti-cold wind function has the priority. The indoor fan
is controlled as shown in Fig. 18.
Setting Actual
T1-Td °F (°C)
Fan Speed Fan Speed
Setting Fan Actual Fan
4.5(40.1) H+(H+=H+G) Speed
T1-Td+34.7°F(1.5°C)
Speed
A H（=H）
H 3.0(37.4) -3°F(-1.5°C) H-（H-=H-G)
B
1.5(34.7) H-（H-=H-G) H -6°F(-3.0°C)
C -10°F(-4.5°C)
H（=H）
H+(H+=H+G)
M+(M+=M+Z)
4.5(40.1)
D M(M=M) -3°F(-1.5°C) M-(M-=M-Z)
M 3.0(37.4) M
E -6°F(-3.0°C)
M(M=M)
1.5(34.7) M-(M-=M-Z) -10°F(-4.5°C)
F M+(M+=M+Z)
L+(L+=L+D) -3°F(-1.5°C)
4.5(40.1) L-(L-=L-D)
G L(L=L) L -6°F(-3.0°C)
L 3.0(37.4) L(L=L)
H -10°F(-4.5°C)
1.5(34.7) L-(L-=L-D) L+(L+=L+D)
I

Fig. 18 — Indoor Fan Running Rules

Fig. 15 — Indoor Fan Table
The AUTO Fan function under the COOLING mode acts (see Fig. 16). AUTO Fan action in HEATING mode

T1-Td
T1-Td+3°F(1.5°C)

6.0°C(13°F) H 0°F(0.0°C) L
5.0°C(11.0°F) a (H-L)*0.75+L -2°F(-1°C) (H+-L)*0.2+L

4.0°C(8°F) b (H-L)*0.5+L -4°F(-2°C) (H+-L)*0.4+L

c (H-L)*0.25+L -6°F(-3°C) (H+-L)*0.6+L
2.5°C(5°F)
d L -8°F(-4°C)
1.0°C(2°F)
e -11.0°F(-5°C) (H+-L)*0.8+L
-13°F(-6°C)
-15°F(-6.5°C) H+
Fig. 16 —AUTO Fan function under the COOLING Mode

Fig. 19 — AUTO Fan action in HEATING mode

16 Specifications subject to change without notice. 38MBR-03SM

Defrosting Mode
If any one of the following conditions are met, AC enters the DEFROSTING mode. After the compressor starts and continues to run, mark the
minimum value of T3 from the 10th minute to 15th minute as T30.

Fig. 20 — Defrosting Chart

38MBR-03SM Specifications subject to change without notice. 17

Evaporator Coil Temperature Protection POINT CHECK FUNCTION
Press the remote controller LED DISPLAY or LED or MUTE three
times, and then press AIR DIRECTION or SWING three times in
T2 ten seconds (the buzzer rings for two seconds). The air conditioner
enters the information enquiry status.
The user can press the LED DISPLAY or AIR DIRECTION to
Off check the next or front item's information. When the air conditioner
TEstop enters the enquiry information status, it displays the code name in 2
Decrease seconds. Refer to Table 17 for details.
TEdown Table 17 — Enquiry Information
Hold ENQUIRY
TEH2 DISPLAYING CODE MEANING
INFORMATION
Resume
T1 T1 T1 temp.
T2 T2 T2 temp.
Fig. 21 — Evaporator Coil Temperature Protection T3 T3 T3 temp.

Off: Compressor stops T4 T4 T4 temp.

Decrease: Decrease the running frequency to the lower level T2B Tb T2B temp.
Hold: Keep the current frequency TP TP TP (T5) temp.
Resume: No limitation for frequency
TH TH TH temp.
Auto Mode Targeted Frequency FT Targeted Frequency
This mode can be chosen with remote controller and the setting
Actual Frequency Fr Actual Frequency
temperature can be changed between 62.6~86F(17~30C).
In AUTO mode, the machine either selects COOLING, HEATING
or FAN-Only mode according to T (T=T1-Ts). Indoor Fan Speed IF Indoor Fan Speed

Outdoor Fan Speed OF Outdoor Fan Speed

ΔT=T1-Ts Running Mode
ΔT≥2F(1℃) Cooling Mode EXV Opening Angle LA EXV Opening Angle
-2°F(-1 ℃ )<ΔT<3(2°F1 ℃ ) Fan-only Mode
Compressor Compressor
ΔT≤-1℃(-2°F) Heating Mode Continuous CT Continuous
Running Time Running Time
The indoor fan runs in the AUTO Fan mode of the relevant mode. Compressor Compressor
ST
Stop Issues Stop Issues
The louver operates same as in relevant mode. If the machine switches
mode between heating and cooling, the compressor will continue to When the air conditioner enters the information enquiry status, the
stop for 15 minutes and then choose a mode according to T1-Ts. If the LED displays the code value within 25 seconds (see Table 18 on
setting temperature is modified, the machine selects a running page 19).
function once again.

DRYING Mode
DRYING mode works the same as COOLING mode in BREEZE
speed. All protections are active and the same as that in the
COOLING mode.

Auto-Restart Function
The indoor unit is equipped with an auto-restart function, which is
carried out through an auto-restart module. In case of a sudden power
failure, the module memorizes the setting conditions before the power
failure. The unit resumes the previous operation setting (not including
sleep function) automatically after 3 minutes when power returns.

18 Specifications subject to change without notice. 38MBR-03SM

Enquiry Information
Table 18 — Enquiry Information
ENQUIRY INFORMATION DISPLAY VALUE MEANING REMARK
- 1F,- 1E,- 1d,- 1c,- 1 - 25,- 24,- 23,- 22,- 21,- 20 1. All the displaying
b,- 1A temperature is actual value.
- 19—99 - 19—99 2. Temperature is _C no
A0,A1,A9 100,101,109 matter the remote.
3. T1,T2,T3,T4,T2B display
T1,T2,T3,T4, T2B,TP,TH, b0,b1,b9 110,111,119 range:- 25~ 70,
Targeted Frequency,
Actual Frequency c0,c1,c9 120,121,129 4. TP display range:- 20~ 130.
d0,d1,d9 130,131,139 5. Frequency display range:
0~159HZ.
E0,E1,E9 140,141,149 6. If the range, it displays the
F0,F1,F9 150,151,159 maximum value or minimum
value.
0 OFF
Low speed, Medium speed, High
1,2,3,4 For some big capacity motors
speed, Turbo
Indoor fan speed/ For some small capacity motors
Outdoor fan speed Actual fan speed = Display value the display value is 14- FF
14- FF turns to decimal value and then (hexadecimal), the corresponding
multiply 10. The unit is RPM. fan speed range is from 200- 2550
RPM.
Actual EXV opening value =
EXV opening angle 0- FF Display value turns to decimal
value and then multiply 2.
If the actual value exceeds the
Compressor continuous 0- FF 0- 255 minutes range, it displays the maximum
running time value or minimum value.
For a detailed meaning, please
Compressor stop causes 0- 99 Decimal display
consult with an engineer
Reserve 0- FF

38MBR-03SM Specifications subject to change without notice. 19

TROUBLESHOOTING
This section provides the required flow charts to troubleshoot For problems requiring measurements at the control boards, note the
problems that may arise. following:
NOTE: Information required in the diagnoses can be found
1. Always disconnect the main power.
either on the wiring diagrams or in the appendix.
2. When possible check the outdoor board first.
Required Tools: 3. Start by removing the outdoor unit top cover.
4. Reconnect the main power
The following tools are needed when diagnosing the units: 5. Probe the outdoor board inputs and outputs with a digital multi-
• Digital multimeter meter referring to the wiring diagrams.
• Screw drivers (Phillips and straight head) 6. Connect the red probe to hot signal and the black probe to the
ground or negative.
• Needle-nose pliers
7. Note that some of the DC voltage signals are pulsating voltages for
• Refrigeration gauges signal. this pulse should be rapidly moving at all times when there
is a signal present.
Recommended Steps 8. If it is necessary to check the indoor unit board you must start by
disconnecting the main power.
1. Refer to the diagnostic hierarchy charts below and determine the 9. Next remove the front cover of the unit and then control box cover.
problem at hand.
10. Carefully remove the indoor board from the control box, place it
2. Go to the chart listed in the diagnostic hierarchy and follow the face up on a plastic surface (not metal).
steps in the chart for the selected problem.
11. Reconnect the main power and repeat steps 5, 6, and 7.
For the ease of service, the systems are equipped with diagnostic code 12. Disconnect main power before reinstalling board to avoid shock
display LED's on both the indoor and outdoor units. The outdoor hazard and board damage.
diagnostic display is on the outdoor unit board and is limited to very
few errors. The indoor diagnostic display is a combination of flashing
LED's on the display panel on the front of the unit. If possible always
check the diagnostic codes displayed on the indoor unit first.
The diagnostic codes for the indoor and outdoor units are listed in the
following pages.
Problems may occur that are not covered by a diagnostic code, but are
covered by the diagnostic flow charts. These problems are typical air
conditioning mechanical or electrical issues that can be corrected
using standard air conditioning repair techniques.

20 Specifications subject to change without notice. 38MBR-03SM

DIAGNOSTIC GUIDES
Table 19 — Indoor Unit Error Display
OPERATION LAMP TIMER LAMP DISPLAY LED STATUS SOLUTION
☆ 1 time X E0 Indoor unit EEPROM parameter error Page 24
☆ 2 times X E1 Communication malfunction between indoor and outdoor units Page 26
☆ 4 times X E3 Fan speed is operating outside of the Normal Range Page 29
☆ 5 times X E4 Indoor room temperature sensor (T1) malfunction Page 30
☆ 6 times X E5 Evaporator coil temperature sensor (T2) malfunction Page 30
☆ 7 times X EC Refrigerant leakage detection Page 31
☆ 8 times X EE Refer to Indoor Unit
Water-level alarm malfunction Service Manual
☆ 1 time O F0 Current overload protection Page 25
☆ 2 times O F1 Outdoor ambient temperature sensor (T4) malfunction Page 30
☆ 3 times O F2 Condenser coil temperature sensor (T3) malfunction Page 30
☆ 4 times O F3 Compressor discharge temperature sensor (T5) malfunction Page 30
☆ 5 times O F4 Outdoor unit EEPROM parameter error Page 24
☆ 6 times O F5 Outdoor fan speed malfunction Page 29
☆ 7 times O F6 Refer to Indoor Unit
Indoor coil outlet pipe sensor (Located on outdoor unit low pressure valve) Service Manual
☆ 8 times O F7 Refer to Indoor Unit
Communication malfunction between the cassette optional lift panel and the unit Service Manual
☆ 9 times O F8 Refer to Indoor Unit
Cassette optional lift panel malfunction Service Manual
☆ 10 times O F9 Refer to Indoor Unit
Cassette optional lift panel not closed Service Manual
☆ 1 time ☆ P0 Inverter module (IPM) malfunction Page 32
☆ 2 times ☆ P1 Over-voltage or under-voltage protection Page 35
☆ 3 times ☆ P2 Compressor top high temperature protection (OLP) Page 36
☆ 4 times ☆ P3 Refer to Indoor Unit
Low ambient temperature cut off in HEATING mode Service Manual
☆ 5 times ☆ P4 Compressor drive malfunction Page 37
☆ 6 times ☆ P5 Refer to Indoor Unit
Indoor units mode conflict Service Manual
☆ 7 times ☆ P6 Refer to Indoor Unit
Low pressure protection Service Manual
☆ 8 times ☆ P7 Outdoor IPM temperature sensor error Page 38

O (light) X (off) ☆(flash)

Table 20 — Error Display on Two Way Communication Wired Controller

DISPLAY LED STATUS SOLUTION
F0 Communication error between wired controller and indoor unit Page 25
F1 The cassette faceplate is abnormal Page 30
E1 Communication malfunction between indoor and outdoor units Page 26
E2 Indoor room temperature sensor (T1) malfunction Refer to Indoor Unit Service Manual
E3 Evaporator coil temperature sensor (T2) malfunction Refer to Indoor Unit Service Manual
E5 Outdoor ambient temperature sensor (T4) malfunction Page 30
E5 Condenser coil temperature sensor (T3) malfunction Page 30
E5 Compressor discharge temperature sensor (T5) malfunction Page 30
E7 Indoor unit EEPROM parameter error Refer to Indoor Unit Service Manual
E8 Indoor fan speed malfunction Refer to Indoor Unit Service Manual
EF Refrigerant leak detection Refer to Indoor Unit Service Manual
EE Water-level alarm malfunction Refer to Indoor Unit Service Manual
ED Outdoor unit EEPROM parameter error Refer to Indoor Unit Service Manual
ED Outdoor fan speed malfunction Refer to Indoor Unit Service Manual
EB Inverter module (IPM) malfunction Refer to Indoor Unit Service Manual
EF Other malfunction

38MBR-03SM Specifications subject to change without notice. 21

DIAGNOSIS AND SOLUTION
Outdoor Unit Error Display
Table 21 — Diagnostic Guide for Outdoor Units
NO. PROBLEMS ERROR CODE SOLUTION

1 Communication malfunction between indoor and outdoor units E1 Page 26

2 Current overload protection F0 Page 25
3 Outdoor ambient temperature sensor (T4) malfunction F1 Page 30
4 Condenser coil temperature sensor (T3) malfunction F2 Page 30
5 Compressor discharge temperature sensor (T5) malfunction F3 Page 30
6 Outdoor unit EEPROM parameter error F4 Page 24
7 Outdoor fan speed malfunction F5 Page 29
8 Inverter module (IPM) malfunction P0 Page 31
9 Over-voltage or under-voltage protection P1 Page 35
10 Compressor top high temperature protection (OLP) P2 Page 36
11 Low ambient temperature cut off in HEATING mode P3 Refer to Indoor Unit Service Manual

12 Compressor drive malfunction P4 Page 37

13 High temperature protection of indoor coil in HEATING mode J0 Page 39
14 Outdoor temperature protection of outdoor coil in COOLING J1 Page 40
15 Temperature protection of compressor discharge J2 Page 41
16 PFC module protection J3 Page 42
17 Communication malfunction between control board and IPM board J4 Page 43
18 High pressure protection J5 Page 44
19 Low pressure protection J6 Page 45
20 Outdoor IPM module temperature sensor malfunction P7 Page 38
21 AC voltage protection J8 Page 46

22 Specifications subject to change without notice. 38MBR-03SM

 Table 22 — Outdoor Check Function
N DISPLAY REMARK
00 Normal display Display running frequency, running state or malfunction code
Actual data*HP*10
If the capacity demand code is higher than 99, the digital display tube displays a single digit and a ten digit. (For
01 Indoor unit capacity demand code example, the digital display tube displays “5.0” it means the capacity demand is 15. The digital display tube displays “60”
it means the capacity demand is 6.0).
02 Amendatory capacity demand code

03 The frequency after the capacity

requirement transfer
04 The frequency after the frequency limit
05 The frequency of sending to 341 chip
If the temp. is lower than 0 degree, the digital display tube displays “0”. If the temp. is higher than 70 degree, the digital
06 Indoor unit evaporator outlet temp.
(HEATING T2，COOLING T2B) display tube displays “70”.
07 Condenser pipe temp.(T3) If the temp. is lower than -9 degree, the digital display tube displays “-9”.If the temp. is higher than 70 degree, the digital
08 Outdoor ambient temp.(T4) display tube displays “70”. If the indoor unit is not connected, the digital display tube displays: “--”

The display value is between 13~129 degree. If the temp. is lower than 13 degrees, the digital display tube displays “13”.
If the temp. is higher than 99 degrees, the digital display tube displays a single digit and a ten digit. (For example, if the
09 Compressor discharge temp.(T5) digital display tube displays “0.5”, it means the compressor discharge temp. is 105 degrees. If the digital display tube
displays “1.6”, it means the compressor discharge temp. is 116 degrees).
10 AD value of current
The display value is a hex number.
11 AD value of voltage
12 Indoor unit running mode code Off:0, Fan only 1,Cooling:2, Heating:3
13 Outdoor unit running mode code Off:0, Fan only 1,Cooling:2, Heating:3, Forced cooling:4
Actual data/4.
14 EXV open angle If the value is higher than 99, the digital display tube displays a single digit and a ten digit.
For example, if the digital display tube displays “2.0”,it means the EXV open angle is 120×4=480p.).
Bit7 Frequency limit caused by IGBT radiator
Bit6 Frequency limit caused by PFC
Bit5 Frequency limit caused by T4
The display value is a hex number. For ex., the
Bit4 Frequency limit caused by T2 digital display tube displays 2A, then Bit5=1,
15 Frequency limit symbol Bit3=1, Bit1=1.
Bit3 Frequency limit caused by T3 It represents the frequency limit caused by T4,
T3 and current.
Bit2 Frequency limit caused by T5
Bit1 Frequency limit caused by current
Bit0 Frequency limit caused by voltage
16 DC fan motor speed
The display value is between 30~120 degrees. If the temp. is lower than 30 degrees, the digital display tube displays
“30”. If the temp. is higher than 99 degrees, the digital display tube displays a single digit and a ten digit. (For example, if
17 IGBT radiator temp. the digital display tube displays “0.5”, it means the IGBT radiator temp. is 105 degrees. If the digital display tube displays
“1.6”, it means the IGBT radiator temp. is 116 degrees).
18 Indoor unit number The indoor unit can communicate well with the outdoor unit. General:1, Twins:2
If the temp. is lower than 0 degree, the digital display tube displays “0”.If the temp. is higher than 70 degrees, the digital
19 Evaporator pipe temp. T2 of1# indoor unit display tube displays “70”. If the indoor unit is not connected, the digital display tube displays: “--”.
20 Evaporator pipe temp. T2 of 2# indoor unit
21 Evaporator pipe temp. T2 of 3# indoor unit
Actual data*HP*10
If the capacity demand code is higher than 99, the digital display tube displays a single digit and a tens digit. (For
22 1# Indoor unit capacity demand code example, the digital display tube displays “5.0”,it means the capacity demand is 15. If the digital display tube displays
“60”,it means the capacity demand is 6.0). If the indoor unit is not connected, the digital display tube displays: “--”.
23 2# Indoor unit capacity demand code
24 3# Indoor unit capacity demand code
25 Room temp. T1 of 1# indoor unit
If the temp. is lower than 0 degree, the digital display tube displays “0”.If the temp. is higher than 70 degrees, the digital
26 Room temp. T1 of 2# indoor unit display tube displays “70”. If the indoor unit is not connected, the digital display tube displays: “--”.
27 Average room temp. T1
28 Reason of stop
29 Evaporator pipe temp. T2B of 1# indoor unit If the temp. is lower than 0 degree, the digital display tube displays “0”.If the temp. is higher than 70 degrees, the digital
30 Evaporator pipe temp. T2B of 2# indoor unit display tube displays “70”. If the indoor unit is not connected, the digital display tube displays: “--”.

38MBR-03SM Specifications subject to change without notice. 23

EEPROM Parameter Error - Diagnosis and Solution (E0/F4)
Error Code E0/F4
Malfunction decision conditions Indoor or outdoor PCB main chip does not receive feedback from EEPROM chip.
• Installation mistake
Supposed Causes
• PCB faulty

Troubleshooting

Power OFF.
Wait 2 minutes then power ON the unit.

Yes

Replace the indoor /outdoor main

. PCB.

EEPROM: A read-only memory whose contents can be erased and reprogrammed using a pulsed voltage. For the location of the EEPROM
chip, refer to the Fig. 22.

Fig. 22 — Outdoor PCB

Figure 22 is for illustration purposes only and may differ from your actual unit.

24 Specifications subject to change without notice. 38MBR-03SM

Overload Current Protection Diagnosis and Solution (F0)
Error Code F0
Malfunction decision conditions An abnormal current rise is detected by checking the specified current detection circuit.
• Power supply problems
• System blockage
Supposed Causes • PCB faulty
• Wiring mistake
• Compressor malfunction

Troubleshooting

Check the power supply No Stop the unit

Yes

Check what is blocking the system No Clear the blockage.

Yes

Check the compressor resistance

No Replace the compressor.
values

Yes

Check the connecƟons and wires No Correct the connecƟons or replace the wires.

Yes

Check the reactor No Replace the outdoor main PCB.

38MBR-03SM Specifications subject to change without notice. 25

Indoor / Outdoor Unit's Communication Error - Diagnosis and Solution (E1)
Error Code E1
Indoor unit does not receive feedback from outdoor unit for 60 seconds, or the outdoor unit does not
Malfunction decision conditions receive feedback from indoor unit for 120 seconds.
• Wiring mistake
Supposed Causes
• Faulty indoor or outdoor PCB

Troubleshooting

E1 displayed

ŽŵŵƵŶŝĐĂƟŽŶŵĂůĨƵŶĐƟŽŶďĞƚǁĞĞŶƚŚĞ
indoor and outdoor units

Power OFF.
Wait 2 minutes then restart the unit.
ŽĞƐƚŚĞƉƌŽďůĞŵƐƟůůĞdžŝƐƚ͍
Yes

Is there any interference such as

too many lamps or powertransformers? Yes Remove the interference or add
Or is the signal wire too long? a magnet ring on the power wire.

No

/ƐƚŚĞƐŝŐŶĂůǁŝƌĞĂƐŚŝĞůĚĐĂďůĞ
ĂŶĚŝƐƚŚĞƐŚŝĞůĚĐĂďůĞĂĞĂƌƚŚŝŶŐ͍ No ĚŽƉƚĂƐŚŝĞůĚĐĂďůĞͬƐŚŝĞůĚĐĂďůĞĞĂƌƚŚŝŶŐ͘

Yes

/ƐƚŚĞƐŝŐŶĂůǁŝƌĞďƌŽŬĞ͍ Yes Replace the signal wire.

No

Are the signal wires

properly inserted on the PCB? No Pull out and re-insert.

Yes

Replace the indoor main PCB.

Is the error resolved?

No

Replace the outdoor main PCB.

26 Specifications subject to change without notice. 38MBR-03SM

 Fig. 23 — DC Voltage Test
Remark
Use a multimeter to test the DC voltage between the outdoor unit’s L2 port and S ports (Fig. 23). The red pin of the multimeter connects with
the L2 port while the black pin is for the S port. When the AC is running normally, the voltage moves alternatively between -50V to 50V.
If the outdoor unit has a malfunction, the voltage moves alternatively with a positive value. If the indoor unit has a malfunction, the voltage
has a certain value.
Example: 10-13VDC small fluctuating amounts indicates indoor unit malfunction.

Fig. 24 — Reactor Resistance Test

Remark
Use a multimeter to test the reactor resistance that does not connect with the capacitor (Fig. 24). The normal values should be around zero
ohm. Otherwise, the reactor has malfunctioned and needs to be replaced.

38MBR-03SM Specifications subject to change without notice. 27

Index 1
Indoor or Outdoor DC Fan Motor (control chip is in the fan motor). Power on and when the unit is in standby, measure the voltage of pin-1
- pin3, pin4 -pin3 in the fan motor connector. If the value of the voltage is not in the range showing in the table below, the PCB has an issue
and needs to be replaced.

Fig. 25 — Control Chip

Table 23 — DC motor voltage input and output

NO. COLOR SIGNAL VOLTAGE
1 Red Vs/Vm 200~380V
2 --- --- ---
3 Black GND OV
4 White Vcc 13.5~16.5V
5 Yellow Vsp 0~6.5V
6 Blue FG 13.5~16.5V

28 Specifications subject to change without notice. 38MBR-03SM

Fan speed is operating outside of the Normal Range (E3/F5)
Error Code E3/F5
When the indoor fan speed maintains a low speed (ex. 300RPM) or a speed that's too high
(ex.1500RPM) for a certain time, the unit stops and the LED displays the failure (E3). When the outdoor
Description fan speed registers below 200RPM or over 1500RPM for an extended period of time, the unit stops and
the LED displays the failure (F5).
• Wiring mistake
• Faulty fan assembly
Supposed Causes
• Faulty fan motor
• Faulty PCB

Troubleshooting

Power OFF. Wait 2 minutes then restart unit.

Does the problem NO The unit is operating normally.

still exist?

YES

Shut OFF the power supply.

Rotate the fan by hand.

Does it turn easily? NO Find the cause of the problem and resolve.

YES

Check the fan motor wiring.

Is it wired properly? Ensure proper connections.

YES

Measure the voltage for

the fan from the PCB.

It is within
normal parameters? NO Replace the indoor/outdoor PCB

YES

Replace the fan motor.

38MBR-03SM Specifications subject to change without notice. 29

Open Circuit or Short Circuit of Temperature Sensor Diagnosis and Solution (E4/E5/F1/F2/F3)
Error Code E4/E5/F1/F2/F3
Malfunction decision conditions If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays the failure.
• Wiring mistake
Supposed Causes
• Sensor faulty

Troubleshooting

Check if the connecƟon between

No ŶƐƵƌĞĂƉƌŽƉĞƌĐŽŶŶĞĐƟŽŶ͘
the temperature sensor and PCB.
Is it wired properly?

Yes

Measure the resistance value of the sensor.

No Replace the sensor.
It is within acceptable parameters?

Yes

Replace the indoor or outdoor main PCB.

Fig. 26 — Test

30 Specifications subject to change without notice. 38MBR-03SM

Refrigerant Leakage Detection Diagnosis and Solution (EC)
Error Code EC
Define the evaporator coil temp.T2 of the compressor just starts running as Tcool. In the beginning 5
Malfunction decision conditions minutes after the compressor starts up, if T2 <Tcool-35.6°F(Tcool-2°C) does not keep continuous 4
seconds and this situation happens 3 times, the display area shows “EC” and AC turns off.
• T2 sensor faulty
Supposed Causes • Indoor PCB faulty
• System problems, such as leakage or blocking

Troubleshooting

Power OFF.
Wait 2 minutes then restart the unit.
ŽĞƐƚŚĞƉƌŽďůĞŵƐƟůůĞdžŝƐƚ͍
Yes

Check the T2
sensor.
Is cool air blowing from the indoor air outlet? Yes
Is it securely
ĂƩĂĐŚĞĚ͍

No Yes

Check the system for leaks.

Are any leaks present? Replace the indoor PCB.

No Yes
Repair the leak and recharge the refrigerant.
Check the system for blockages and
ŝĨĂŶLJĞdžŝƐƚ͕ĐůĞĂƌƚŚĞŵ͘

38MBR-03SM Specifications subject to change without notice. 31

IPM Malfunction or IGBT Over-strong Current Protection Diagnosis and Solution (PO)
Error Code PO
When the voltage signal that IPM sends to the compressor drive chip is abnormal, the LED displays
Malfunction decision conditions “PO” and the AC turns off.
• Wiring mistake
• IPM malfunction
Supposed Causes • Outdoor fan assembly faulty
• Compressor malfunction
• Outdoor PCB faulty

Troubleshooting

Check the wiring between

the main PCB and the compressor. Yes ŶƐƵƌĞĂƉƌŽƉĞƌĐŽŶŶĞĐƟŽŶŽƌ
Is there an error? ƌĞƉůĂĐĞƚŚĞǁŝƌĞƐĂŶĚĐŽŶŶĞĐƚŽƌƐ͘

No

Check the IPM.

Is it in working order? No ZĞƉůĂĐĞƚŚĞ/WDďŽĂƌĚŽƌƌĞƉůĂĐĞƚŚĞŵĂŝŶW͘

Yes

Check the outdoor fan and WůĞĂƐĞƌĞĨĞƌƚŽƚŚĞ

ƚŚĞŽƵƚĚŽŽƌƵŶŝƚǀĞŶƟůĂƟŽŶ͘ No ͞&ĂŶ^ƉĞĞĚŝƐŽƵƚŽĨĐŽŶƚƌŽůŵĂůĨƵŶĐƟŽŶ͟
Are they in working order? ƐŽůƵƟŽŶ͘

Yes

ŚĞĐŬƚŚĞĐŽŵƉƌĞƐƐŽƌƌĞƐŝƐƚĂŶĐĞǀĂůƵĞƐ͘ ZĞƉůĂĐĞƚŚĞĐŽŵƉƌĞƐƐŽƌ͘
No
ƌĞƚŚĞLJǁŝƚŚŝŶĂĐĐĞƉƚĂďůĞƉĂƌĂŵĞƚĞƌƐ͍

Yes

ZĞƉůĂĐĞƚŚĞŽƵƚĚŽŽƌŵĂŝŶW͘

NOTE: In figures 27-28 the following is observed:

• U,V,W references the compressor connection point
• P references input voltage
• N references output voltage

32 Specifications subject to change without notice. 38MBR-03SM

 Fig. 27 — P-U

Fig. 28 — P-V

38MBR-03SM Specifications subject to change without notice. 33

 Fig. 29 — P-W

Fig. 30 — P-N

34 Specifications subject to change without notice. 38MBR-03SM

Over Voltage or Too Low Voltage Protection Diagnosis and Solution (P1)
Error Code P1
Malfunction decision conditions An abnormal current rise is detected by checking the specified current detection circuit.
• Power supply problems
Supposed Causes • System leakage or blockage
• PCB faulty

Troubleshooting

ŚĞĐŬƚŚĞƉŽǁĞƌƐƵƉƉůLJ͘
/ƐŝƚŝŶǁŽƌŬŝŶŐŽƌĚĞƌ͍ EŽ dƵƌŶŽīƚŚĞƵŶŝƚ͘

zĞƐ

ŚĞĐŬƚŚĞĐŽŶŶĞĐƟŽŶƐĂŶĚǁŝƌĞƐ͘
ƌĞƚŚĞLJŝŶǁŽƌŬŝŶŐŽƌĚĞƌ͍ EŽ ŶƐƵƌĞƚŚĞƉƌŽƉĞƌĐŽŶŶĞĐƟŽŶƐ
ŽƌƌĞƉůĂĐĞƚŚĞǁŝƌĞƐ͘

YeƐ

dƵƌŶƉŽǁĞƌŽŶĂŶĚǁŚŝůĞƚŚĞ
ƵŶŝƚŝƐŝŶƐƚĂŶĚďLJ͕ĐŚĞĐŬŝĨƚŚĞǀŽůƚĂŐĞŝƐ
ďĞƚǁĞĞŶWĂŶĚEŝƐĂƚϯϭϬs͕ϯϰϬsŽƌϯϴϬs͍ ZĞƉůĂĐĞƚŚĞ/WDďŽĂƌĚ͘
EŽ
EĞdžƚ͕ƐƚĂƌƚƚŚĞƵŶŝƚĂŶĚŵĞĂƐƵƌĞƚŚĞ
ǀŽůƚĂŐĞďĞƚǁĞĞŶWĂŶĚE͘
/ƐŝƚďĞƚǁĞĞŶϮϮϬsΕϰϬϬs͍

zĞƐ

ŚĞĐŬƚŚĞƌĞĂĐƚŽƌ͘ ZĞƉůĂĐĞƚŚĞŽƵƚĚŽŽƌŵĂŝŶW͘
EŽ
/ƐŝƚŝŶǁŽƌŬŝŶŐŽƌĚĞƌ͍

zĞƐ

ZĞƉůĂĐĞƚŚĞƌĞĂĐƚŽƌ͘

Fig. 31 — Test

38MBR-03SM Specifications subject to change without notice. 35

High Temperature Protection of Compressor Top Diagnosis and Solution (P2)
Error Code P2
Malfunction decision conditions If the sampling voltage is not 5V, the LED displays the failure.
• Power supply problems
Supposed Causes • System leakage or block
• PCB faulty

Troubleshooting

Check the indoor and outdoor unit’s Clear up the air inlet and outlet or the heat
Yes
ĂŝƌŇŽǁƐLJƐƚĞŵƐ͘ exchanger of the indoor and outdoor units.
Does a problem exist?

No

Power OFF.
Wait 10 minutes and re-start the unit.

Yes

Check the compressor temperature. Check the overload protector.

No No ŶƐƵƌĞĂƉƌŽƉĞƌĐŽŶŶĞĐƟŽŶ͘
Is it within acceptable parameters? Is it properly wired?

Yes Yes

Check the refrigerant system. Measure the resistance between the

/ƐŝƚĨƵŶĐƟŽŶŝŶŐƉƌŽƉĞƌůLJ͍ two OLP ports.
No Replace the OLP.
Is it zero?

Yes

Yes Replace the outdoor control PCB.

36 Specifications subject to change without notice. 38MBR-03SM

Inverter Compressor Drive Error Diagnosis and Solution (P4)
Error Code P4
An abnormal inverter compressor drive is detected by a special detection circuit, including
Malfunction decision conditions communication signal detection, voltage detection, compressor rotation speed signal detection and so
on.
• Wiring mistake
• IPM malfunction
Supposed Causes • Outdoor fan assembly fault
• Compressor malfunction
• Outdoor PCB faulty

Troubleshooting

Check the wiring between the ŶƐƵƌĞƉƌŽƉĞƌĐŽŶŶĞĐƟŽŶŽƌ

Yes
main PCB and compressor. replace the wires and connectors.
Is it improperly wired?

No

Check the IPM.

/ƐŝƚĨƵŶĐƟŽŶŝŶŐƉƌŽƉĞƌůLJ͍ No Replace the IPM board
or replace the main PCB.

Yes

Check the outdoor fan and the

Please refer to
ŽƵƚĚŽŽƌƵŶŝƚǀĞŶƟůĂƟŽŶ͘ No
͞&ĂŶ^ƉĞĞĚDĂůĨƵŶĐƟŽŶ͟ƐĞĐƟŽŶ͘
/ƐŝƚĨƵŶĐƟŽŶŝŶŐƉƌŽƉĞƌůLJ͍

Yes

Check the compressor resistance values. No Replace the compressor.

Are they within acceptable parameters?

Yes

Replace the
outdoor main PCB.

37 Specifications subject to change without notice. 38MBR-03SM

Outdoor IPM Module Temperature Sensor Malfunction Diagnosis and Solution (P7)
Error Code P7
Malfunction decision conditions If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays a failure.
• Faulty wiring
Supposed Causes
• Faulty sensor

Troubleshooting

ŚĞĐŬƚŚĞĐŽŶŶĞĐƟŽŶďĞƚǁĞĞŶƚŚĞ
temperature sensor and the PCB. No ŶƐƵƌĞĂƉƌŽƉĞƌĐŽŶŶĞĐƟŽŶ͘
/ƐŝƚƉƌŽƉĞƌůLJǁŝƌĞĚ͍

Yes

Measure the sensor’s resistance value.

No Replace the sensor.
/ƐŝƚǁŝƚŚŝŶĂĐĐĞƉƚĂďůĞƉĂƌĂŵĞƚĞƌƐ͍

Yes

Replace the outdoor main PCB.

38 Specifications subject to change without notice. 38MBR-03SM

J0 Malfunction
Error Code J0
When the evaporator coil is more than 140°F(60°C), the unit stops. It starts up again only when the
Malfunction decision conditions evaporator coil is less than 129°F(54°C).
• Faulty evaporator coil temperature sensor
• Dirty heat exchanger
Supposed Causes
• Faulty fan
• Faulty PCB

Troubleshooting

J0 displayed

Evaporator high
temperature protecƟon

Is the connecƟon
between T2 and the
Is the compressor PCB in working
No No Correct the connecƟon.
operaƟng? order?
Has T2 and T2B been
Yes
reversed?

Is the outdoor
Yes
ambient temp. higher Yes Stop the unit.
than 86°F (30°C)?

No
Is the resistance of
Replace the
T2 normal according No
Is the air outlet temp. sensor.
Yes Clean the air outlet. to Appendix 1?
blocked?

No
Refer to the Fan Speed
Out of Control
Is the indoor fan
No malfuncƟon soluƟon.
running normally?
Find the cause and
resolve the problem.
Yes

Are the heat exchanger Clean the heat

Yes
and Įůter dirty? exchanger and Įůter.

No

Replace the
Yes
indoor main PCB.

39 Specifications subject to change without notice. 38MBR-03SM

J1 Malfunction
Error Code J1
When the outdoor pipe temperature is more than 149°F(65°C), the unit stops. It starts up again only
Malfunction decision conditions when the outdoor pipe temperature is less than 126°F(52°C).
• Faulty condenser temperature sensor
Supposed Causes • Dirty heat exchanger
• System leakage or blockage

Troubleshooting

J1 displayed

High temperature
condenser protecƟon

Is the connecƟon
Is the compressor between the
temperature higher No temperature sensor No Correct the connecƟon.
than 149°F (65°C)? and the PCB in
working order?
Yes

Is the outdoor
Yes
ambient temp. higher Yes Stop the unit.
than 122°F (50°C)?

No Is the resistance of
the condenser temp.
Replace the
Is the outdoor unit Ensure the outdoor sensor normal No
temp. sensor.
venƟůaƟon funcƟoning No unit vent is according to
properly? funcƟoning properly? Appendix 1?

Yes
Refer to the Fan Speed
Out of Control
Is the outdoor fan
No malfuncƟon soluƟon.
running normally?
Find the cause and
resolve the problem.
Yes

Is the heat Clean the

Yes
exchanger dirty? heat exchanger.

No

Replace the
outdoor main board.
Yes
Has the problem
been solved?

No

If the refrigerant level is

not suĸcient, does the
system work aŌer the
refrigerant is added?

No

Check whether the

refrigerant system is
funcƟoning normally.

40 Specifications subject to change without notice. 38MBR-03SM

J2 Malfunction
Error Code J2
When the compressor discharge temperature (T5) is more than 115°C for 10 seconds, the compressor
Malfunction decision conditions will stop and not restart until T5 is less than 90°C.
• Refrigerant leakage
• Faulty wiring
Supposed Causes
• Faulty discharge temperature sensor
• Faulty outdoor PCB

Troubleshooting

J2 displayed

Temperature protecƟon
of condenser discharge

Is the compressor
Is the refrigerant Stop the leak and
temperature higher Yes Yes
leaking? add refrigerant.
than 239° F (115° C)?

No No

Are the compressor

discharge temp. sensor
Fix the wiring
and PCB connected No
connecƟon.
properly according to
the wiring diagrams?

Yes

Measure the
compressor discharge
temp. sensor’s resistance value.
Replace the compressor
Is the value abnormal? No
discharge temp. sensor.
Refer to Appendix 2.
Does the problem
sƟůů exist?

Yes

Replace the
outdoor main PCB.
Does the problem sƟůů
exist?

No

Replace the
high pressure valve assembly.

38MBR-03SM Specifications subject to change without notice. 41

J3 Malfunction
Error Code J3
When the voltage signal that the IPM sends to the compressor is abnormal, the display LED shows “J3”
Malfunction decision conditions and the unit turns off.
• Faulty wiring
• Faulty IPM board
Supposed Causes • Faulty outdoor fan assembly
• Compressor malfunction
• Faulty outdoor PCB

Troubleshooting

J3 displayed

PFC module protecƟon

Check whether the

connecƟng line
between the main Tighten the
No
board and the PFC connecƟon.
module is connected
lightly.

Yes No

Measure whether the

voltage between Replace the outdoor
Yes
P and N is normal. main board.
Refer to Appendix 3.

Yes
No

Check whether the

PFC module’s inductance is good.
No Replace the inductance.
If it is, the resistance of the
two ports is 0.

Yes

Replace the PFC module. Problem solved.

42 Specifications subject to change without notice. 38MBR-03SM

J4 Malfunction
Error Code J4
When the signal from the IPM to the Main Control Board and IPM Board is abnormal, the display LED
Malfunction decision conditions shows “J4” and the unit turns off.
• Faulty wiring
• Faulty IPM Outdoor board
Supposed Causes
• Faulty Main Outdoor board
• Faulty rectifier

Troubleshooting

J4 displayed

CommunicaƟon error
between the outdoor
main chip and the
compressor drive board.

Is there at least one LED

in the compressor
drive board light?

No

Check the signal wire

between the
compressor drive board Yes
and the main board, it is
connected properly?

No
Yes

Reconnect and retry.

Does the error
sƟůů exist?

Yes

No
Replace the
compressor drive board..
Yes
Is the system running
normally?

No

Replace the outdoor

main board.
Yes
Is the system running
normally?

No

Replace the electric

Problem solved.
control box.

38MBR-03SM Specifications subject to change without notice. 43

J5 Malfunction
Error Code J5
Malfunction decision conditions The sampling voltage is not 5V, the LED displays a failure code.
• Faulty wiring
• Faulty overload protector
Supposed Causes
• System blockage
• Faulty outdoor PCB

Troubleshooting

J5 displayed

High pressure protecƟon

Are the high pressure

Connect the high pressure
switch and main control No
switch and main control board.
board wired correctly?

Yes

Is the high pressure

protector broken?

Method: Disconnect the plug.

Measure the high pressure
Replace the high pressure
protector resistance. If the No
protector.
protector is normal, the value is
0. Does the problem sƟůů exist?

Yes

Is the outdoor ambient

temperature higher Yes Stop the unit.
than 122 F (50 C)

No

Check if the outdoor Ensure the outdoor unit venƟůaƟon

No
unit venƟlaƟon is good. is funcƟoning properly.

Yes

Refer to the Fan Speed Out of

Is the outdoor fan
No Control MalfuncƟon soluƟon.
running properly?
IdenƟfy then cause and resolve it.

Yes

Is the
Yes Clean the heat exchanger.
heat exchanger dirty?

No

Replace the
outdoor main
board.
Is the problem
resolved?
No

Check whether the refrigerant

system is funcƟoning properly.

44 Specifications subject to change without notice. 38MBR-03SM

J6 Malfunction
Error Code J6/P6
Malfunction decision conditions If the sampling voltage is not 5V, the LED displays a failure code.
• Faulty wiring
• Faulty overload protector
Supposed Causes
• System blockage
• Faulty outdoor PCB

Troubleshooting

J6 displayed

Low pressure protecƟon

Are the low pressure Connect the low pressure

switch and main control No protector and main control
board wired correctly? board.

Yes

Is the low pressure

protector broken?

Method: Disconnect the plug.

Measure the low pressure
Replace the high pressure
protector resistance. If the No
protector.
protector is normal, the value is
0. Does the problem sƟůů exist?

Yes

Is the outdoor ambient

Yes Stop the unit.
temperature too low?

No

Is the core value of the

Open the valve core of the
high pressure valve No
high pressure valve.
opened fully?

Yes

Is the indoor fan Refer to the Fan Speed Out of

running properly in the No Control MalfuncƟon soluƟon.
COOLING mode? IdenƟfy the cause and resolve.

Yes

Replace the
outdoor main
board.
Is the problem
resolved?

No

When the refrigerant level is not

suĸcient, does the system
funcƟon properly aŌer more
refrigerant is added?
No

Check whether the refrigerant

system is funcƟoning properly.

38MBR-03SM Specifications subject to change without notice. 45

J8 Malfunction
Error Code J8
Malfunction decision conditions An abnormal voltage rise or drop is detected by checking the specified voltage detection circuit.
• Faulty or wrong power supply
• Faulty wiring
Supposed Causes
• Faulty bridge rectifier
• Faulty IPM board

Troubleshooting

J8 displayed

AC power input voltage protecƟon

Check whether the

Restart the unit when the
power voltage is No
power supply is normal.
normal.

Yes

Measure whether
Verify the wires are well Reconnect
the outdoor terminal No
connected. well.
voltage is normal.

Yes

Measure whether
Ensure L and N wiring is Reconnect
the voltage between L No
correct. well.
and N is normal.

Yes

Is the bridge recƟĮer’s Ensure the bridge recƟĮer Reconnect

No
input voltage normal? wiring is correct. well.

Yes

Measure is the voltage

Check whether Replace
between P and N is
No the bridge recƟĮer is No the bridge
normal.
normal. recƟĮer.
Refer to Appendix 3.

Yes

Replace the PFC module (if available)

No

Yes
Check the reactor Reconnect
or inductance wiring . No
the wiring.

Yes

Replace the IPB board.

If the IPM and main Ensure the Replace the
boards are in a board, Yes reactor or inductance No reactor or
replace the outdoor is normal. inductance.
main board.

46 Specifications subject to change without notice. 38MBR-03SM

Main Parts Check
Temperature sensor checking
Disconnect the temperature sensor from PCB, measure the resistance value with a tester.

Temperature sensors:
• Room temp. (T1) sensor,
• Indoor coil temp. (T2) sensor,
• Outdoor coil temp. (T3) sensor,
• Outdoor ambient temp. (T4) sensor,
• Compressor discharge temp. (T5) sensor.
Measure the resistance value of each winding by using the multi-meter.

38MBR-03SM Specifications subject to change without notice. 47

Compressor Checking
Measure the resistance value of each winding by using the tester.

NOMINAL RESISTANCE VALUE

POSITION
ATF310D43UMT ATQ420D1UMU

Blue - Red
Blue - Black 0.65Ω 0.38Ω
Red - Blue

IPM Continuity Check

Turn off the power, let the large capacity electrolytic capacitors discharge completely, and dismount the IPM. Use a digital tester to measure the
resistance between P and UVWN; UVW and N.

NORMAL
DIGITAL TESTER RESISTANCE DIGITAL TESTER NORMAL RESISTANCE VALUE
VALUE
(+)Red (-)Black (+)Red (-)Black
N U
∞ ∞
U V
P (Several MΩ) N (Several MΩ)
V W
W (+)Red

48 Specifications subject to change without notice. 38MBR-03SM

Pressure on Service Port
Cooling Charts (Cooling Mode)

INDOOR OUTDOOR TEMP.

F C TEMP 75 (23.89) 85 (29.44) 95 (35) 105 (40.56) 115 (46.11)
BAR 70 8.2 7.8 8.1 8.6 10.1
BAR 75 8.6 8.3 8.7 9.1 10.7
BAR 80 9.3 8.9 9.1 9.6 11.2

PSI 70 119 113 117 125 147

PSI 75 124 120 126 132 155
PSI 80 135 129 132 140 162

MPA 70 0.82 0.78 0.81 0.86 1.01

MPA 75 0.86 0.83 0.87 0.91 1.07
MPA 80 0.93 0.89 0.91 0.96 1.12

Pressure (bar)
12.0

10.0

8.0

6.0 70
75

4.0 80

2.0

0.0
Outdoor temp.
75 （23.89） 85 （29.44） 95 105 115
（35） （40.56） （46.11）

38MBR-03SM Specifications subject to change without notice. 49

Pressure on Service Port (cont.)
Heating Charts (Heating Mode)

INDOOR OUTDOOR TEMP.

F C TEMP. 57 (13.89) 47 (8.33) 37 (2.78) 27 (-2.78) 17 (-8.33)
BAR 55 30.3 28.5 25.3 22.8 20.8
BAR 65 32.5 30.0 26.6 25.4 23.3
BAR 75 33.8 31.5 27.8 26.3 24.9

PSI 55 439 413 367 330 302

PSI 65 471 435 386 368 339
PSI 75 489 457 403 381 362

MPA 55 3.03 2.85 2.53 2.28 2.08

MPA 65 3.25 3.00 2.66 2.54 2.33
MPA 75 3.38 3.15 2.78 2.63 2.49

Pressure (bar)

40.0

35.0

30.0

25.0
55
20.0
65
15.0
75
10.0

5.0

0.0 Outdoor temp.

57 (13.89) 47 (8.33) 37 (2.78) 27 17
(-2.78) (-8.33)

50 Specifications subject to change without notice. 38MBR-03SM

DISASSEMBLY INSTRUCTIONS SIZE 36

No. Part name Procedures Remarks

1 Panel plate Remove the panel plate
Big handle (4 screws)

Screws of top panel (3screws, 1screws is under the big handle)

1) Stop the air conditioner

and turn off the power
breaker.

Screws of big
handle
\ (3 screws)

2) Remove the big handle

first, then remove the top Front panel screws (11)
cover (7 screws).

4
3) Remove the front panel
screws (11 screws).

(4) Remove the right side 3

panel screws (13).

38MBR-03SM Specifications subject to change without notice. 51

DISASSEMBLY INSTRUCTIONS SIZE 36 (CONT)

2 Fan Assembly Remove the fan assembly

Fan Electronic control box

1) Use procedure 1 to
remove the panel plate.

compressor

2) Remove the nut securing

the fan, then remove the
fan.

3) Unfix the hooks and

remove the screws.
Next, open the electronic
control box cover.

52 Specifications subject to change without notice. 38MBR-03SM

DISASSEMBLY INSTRUCTIONS SIZE 36 (CONT)

T3,T4,T5,sensor Pressure switch Compressor wire

4) Disconnect the fan motor

connector from the
electronic control board.
Electronic expansion 4 way valve Motor wire
4

5) Remove the fan motor’s

four screws (4) then
remove the motor.

38MBR-03SM Specifications subject to change without notice. 53

DISASSEMBLY INSTRUCTIONS SIZE 36 (CONT)

3 Electrical Remove the electrical parts

parts 1

1) After completing steps

in sections 1 and 2,
remove the compressor
connector.

2) Pull out the two blue

wires connected with
the 4-way valve.

3) Pull out the condenser

coil temp. sensor (T3)
connectors, outdoor
ambient temp. sensor
(T4), and the discharge
temp. sensor (T5).

54 Specifications subject to change without notice. 38MBR-03SM

DISASSEMBLY INSTRUCTIONS SIZE 36 (CONT)

4) Disconnect the pressure

switch connector.

5) Disconnect the electronic

expansion valve from
the control board.

6
7

6) Remove the ground

wires.

7) Remove the wires (1,2,3

or L1,L2, S). Next,
remove the electronic
control box.

38MBR-03SM Specifications subject to change without notice. 55

DISASSEMBLY INSTRUCTIONS SIZE 36 (CONT)

4 4-Way Valve Remove the 4-way valve

The picture of the 4-way may differ from your actual
valve.
1) Complete the steps in
sections 1 and 3.

2) Recover refrigerant from

the refrigerant coil.

3) Remove the coil screw

then remove the coil.

4) Detach the 4-way valve’s

and pipe’s welded parts.

5) Remove the 4-way valve

assembly.
3 4

5 Compressor Remove the compressor 2

1) After completing the

steps in sections 1 and 3,
recover the refrigerant
from the refrigerant
circuit.

2) Remove the discharge

pipe and the suction
pipe with a burner.

3) Remove the hex nuts

and washers securing
the compressor on the
bottom plate.

4) Lift the compressor from

the base pan assembly.

56 Specifications subject to change without notice. 38MBR-03SM

DISASSEMBLY INSTRUCTIONS SIZE 48-58

No. Part name Procedures Remarks

1 Fan assembly Remove the fan assembly

1) Stop the air conditioner and

turn off the power breaker.

2) Remove the air outlet grille

screws (8).

3) Remove the hex nut securing

the fan.

4) Remove the fan.

Top cover screws

5) Remove the top cover screws

(4) then remove the top cover.

38MBR-03SM Specifications subject to change without notice. 57

DISASSEMBLY INSTRUCTIONS SIZE 48-58 (CONT)

6) Remove the right front side

screws and the right front
side panel (1 screw).

7) Disconnect the fan motor

connectors FAN (3p, white)
and FAN2 (3p, white) from
the DC motor driver board.

8) Remove the fan motor after

unfastening the securing
screws.

2 Panel plate Remove the panel plate.

1) Remove the big handle

(2 screws) and the water
collector (2 screws). Big handle screws

2) Remove the terminal board Water collector screws

screws (2) and the right-rear
panel screws (7) and remove
the right-rear panel.
Right-rear screws

58 Specifications subject to change without notice. 38MBR-03SM

DISASSEMBLY INSTRUCTIONS SIZE 48-58 (CONT)

Right-rear panel
screws

3 Electrical Remove the electrical parts

parts

1) Complete steps 5 - 6 in
section 1 and section 2.

IPM board PCB board DC Fan

Driver board

2) Disconnect the fan motor

connector (5p, white) from
the IPM board.

3) Disconnect the following

eight (8) connection wires
and connectors between
the IPM and the other parts.

38MBR-03SM Specifications subject to change without notice. 59

DISASSEMBLY INSTRUCTIONS SIZE 48-58 (CONT)

CN2(yellow)

CN1(red)

CN6(black)

CN3(yellow)

U V W(black)

CN9(10p,white)

4) Remove the screws securing

the IPM board and remove
the IBM board.

5) Disconnect the connectors and

wires connected from the PCB
and other parts.

Connectors:
CN8: Discharge temperature sensor
CN1/CN3
(2p,white)
CN12 Heatsink temperature
sensor(2p,red)
CN9:T3/T4 temperature sensor
(2p/2p,white)
CN15: Electronic expansive valve
(6p,red)
CN10: High and low pressure switch
(2p/2p, white)

CN17/CN18

Wires: CN19/CN20
CN17/CN18: 4-way valve (blue-blue) CN24/CN25
CN19/CN20: connected to crankcase
heating cable. (black-red)
CN24/CN25: Electric heater of
chassis (orange-orange)
CN1:L-IN (red or white)
CN3:N-IN (black)

60 Specifications subject to change without notice. 38MBR-03SM

DISASSEMBLY INSTRUCTIONS SIZE 48-58 (CONT)

6) Disconnect the grounding wire

(yellow-green) after removal
of the big handle.

7) Remove the PCB board.

4 Compressor Remove the compressor.

1) Complete steps 5 - 6 in
section and section 2.

2) Extract the refrigerant gas.

3) Remove the sound insultation

material and crankcase
heating cable.

4) Remove the compressor

terminal cover and
disconnect the crankcase
electric heater wires and
compressor from the
terminal.

5) Remove the discharge pipe

and suction pipe with a
burner.

6) Remove the hex nuts and

washers securing the
compressor to the bottom
plate.

7) Lift the compressor.

38MBR-03SM Specifications subject to change without notice. 61

DISASSEMBLY INSTRUCTIONS SIZE 48-58 (CONT)

5 The 4-way Remove the 4-way valve

valve
1) Complete steps 5 - 6 of
section 1 and section 2.

Coil
2) Extract the refrigerant gas.
Welded parts
3) Remove the electrical parts
in section 3.

4) Remove the coil screw and

remove the coil.

5) Detach the welded parts of

the 4-way valve and pipe.

6 Expansion Remove the expansion valve

valve

1) Complete the steps in

sections 1 - 2.
Expansion
2) Remove the electrical parts valves
described in section 3.

3) Remove the coil.

4) Detach the expansion valves

welded parts and pipes.

Copyright 2019 CAC/BDP D 3300 Riverwood Parkway Atlanta GA, 30339 Edition Date: 07/19 Catalog No. 38MBR-03SM

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. Replaces: 38MBR-02SM