NUVEOT90LSERVICEMANUAL
NUVEOT90LSERVICEMANUAL
NUVEOT90LSERVICEMANUAL
OT 90L
SERVICE MANUAL
Factory
EsenboğaYolu 22. Km.
Akyurt 06287
ANKARA
Tel: (0.312) 399 22 09 / 399 28 30
Fax: (90.312) 399 21 97
email: nuveservice@nuve.com.tr
2
CONTENTS
Page
1. INTRODUCTION 4
1.1. PURPOSE OF THE SERVICE MANUAL 4
1.2. GENERAL PURPOSE OF THE UNIT 4
2. OPERATING PRINCIPLES 5
2.1. POWER SUPPLY 6
2.2. MAIN PCB 6
2.3. CONTROL PANEL 7
2.4. HEATER UNIT 7
2.5. WATER AND STEAM UNIT 8
3. SERVICING 9
3.1. GENERAL OVERVIEW 9
3.2. GENERAL FAILURES 9
3.3. TEMPERATURE CONTROL PROCESS FAİLURES 11
3.4. SSR CONTROL 15
4. SPARE PART REPLACEMENT 16
4.1. REPLACING MAIN PCB 18
4.2. REPLACING CONTROL PANEL 18
4.3. REPLACING TEMPERATURE SENSOR 19
4.3.1. PT-1 19
4.3.2. PT-2 20
4.3.3. PT-3 20
4.4. REPLACING SOLENOID VALVE 21
4.5. REPLACING SSR 22
4.6. REPLACING SAFETY VALVE 22
4.7. REPLACING CHAMBER GASKET 23
4.8. REPLACING PLASTIC PANEL 23
4.9. REPLACING SAFETY THERMOSTAT 24
4.10. REPLACING COOLING FAN 25
4.11. REPLACING LOCKING BOBBIN 25
4.12. REPLACING DOOR SWITCH 26
4.13. REPLACING SURFACE THERMOSTAT 26
4.14. REPLACING PRESSURE SWITCH 27
4.15. REPLACING STEAM TRAP 27
4.16. REPLACING GASKET HEATER 28
4.17. REPLACING MANOMETER 28
4.18. REPLACING SWITCH OF DRAIN WATER TANK 29
5. ELECTRICAL CIRCUIT DIAGRAM 30
6. SPARE PARTS LIST 31
3
1. INTRODUCTION
1.1. PURPOSE OF THE SERVICE MANUAL
This manual includes servicing and maintenance information for OT 90L Vertical Steam
Sterilizers. It is prepared to be used by technicians who were formerly trained by Nuve. This
manual informs the technicians about the operating principles, diagnosing and repairing
methods and spare part replacing.
If any problem is detected which is not identified in this manual, please contact to Nuve
Servicing Team.
The heating function is provided by means of three heaterslocated inside the sterilization
chamber. The sterilization cycle consists of the heating, sterilization and cooling.
Heating: In this process,the sterilization chamber is heated to reach required steam
temperature before the sterilization process.
Sterilization: Thisprocess starts when the temperature in the chamber reaches to the set
temperature. The sterilization chamber is kept at the required temperature during the set time.
Cooling: In this process, the steam in the chamber is cooled by the cooling fan until the
pressure drops to zero. The samples are cooled in this phase.
There are two special programs for liquid and solid. Sterilization temperaturefor these special
programs is programmable between 105°C and 135°C and sterilization timer is programmable
between 1 - 300 minutes for these special programs. In addition, there is a melting program
which the temperature is programmable between 60°C and 100°C and timer is programmable
between 1 and 60 minutes.
In OT 90L Vertical Laboratory Steam Sterilizers, the steam is produced by the heaters located
inside the chamber. Thus, homogenous temperature variation is maintained in the sterilization
chamber. The sterilization duration is decreased by pre-heating system. All parts which are
exposed to steam and water are made of stainless materials.
4
Besides safety features ofcontrol panel (unexpected high pressure and temperature, etc.), OT
90L has safety thermostat and pressure switch as an additional safety feature.
LID HANDLE
CHAMBER MANOMETER
CONTROL PANEL
Figure 1
2. OPERATING PRINCIPLES
OT 90L can be examined in 5 main categories:
• Power supply
• Main PCB
• Control panel
• Heating unit
• Steam unit
5
2.1. POWER SUPPLY
All of the command and control elements are connected to the main PCB. These are:
• Temperature sensor
• Display board
• Heater group supply terminals
• Fan
Figure 2
6
2.3. CONTROL PANEL
Control panel is illustrated in figure 3. Please see the user’s manual for detail information about
function of the control panel.
Figure 3
F1, F2, F3 and F4 buttons are named with the first letter of “function” and their functions
correspond to the commands on the display.
Figure 4
7
2.5. WATER AND STEAM UNIT
The sterilization principle of OT 90L is based on water vapor with high pressure. Water vapor is
obtained by heating water in the chamber. The pressure in the chamber can be followed on the
manometer on the device.
Solenoid valve in the steam system is controlled by main PCB controlled with microprocessor.
If the pressure in the chamber exceeds 3 bars, pressure switch is activated and the circuit is cut.
In addition, if the pressure in the chamber exceeds 3 bars, the safety valve is activatedand
discharges the excess steamcausing over-pressure automatically.
If the water in the chamber is insufficient, safety thermostat connected to the heaters is
activated and stops heating process.
The exhaust tank is on the right side of the device. The necessary water for sterilization is filled
inside the chamber manually and the condensed steam is discharged to the exhaust tank. There
should be water between minimum and maximum level in the exhaust tank. If water level in the
tank exceeds maximum level, the tank should be removed and empty it up to minimum level.
The components of the water and steam unit are listed below,
• Heater
• Temperature sensor
• Solenoid valve
• Steam trap
• Safety valve (3 Bar)
Figure 5
8
3. SERVICING
Before servicing the instrument, please take the necessary precautions for your
health. Please respect to the warnings on the unit.
The components on the main PCB or display PCB cannot be replaced even the failure is caused
by one of them. In such cases, please send the failed PCB to the factory service along with a
note on which the failure explanations are written.
Please make sure that the failure is not caused by weak wire and terminal connections before
replacing the PCB or any command and control element.
2) The power switch Connection cable between the Disconnect this connection cable
is ON but the display main PCB and display PCB is not and reconnect it carefully.
is blank or some connected properly.
segments are blank.
Connection cable between the Replace the connection cable.
main PCB and display PCB is
defective.
9
FAILURE PROBABLE CAUSES SOLUTION
3)The power switch is Cable of power key is connected Check the connection and connect it
OFF but display is on. adversely. correctly.
4) The fuse has blown Short circuit exists. Check whether there is short
permanently. circuiton the heaters in the chamber
and jacket heater. If short circuit
exists, then replace the
corresponding heaters.
Main PCB does not send any Check the output of the main PCB is
signal to SSR 12 V DC by using multimeter. If not,
replace the motor driver PCB.
10
FAILURE PROBABLE CAUSES SOLUTION
7) The lid is not The locking mechanism is Check the locking mechanism.
locked when the defective.
steam sterilizer
starts operating.
The locking bobbin is defective. Replace the locking bobbin.
The main PCB does not send any Check locking bobbin output of the
signal to the locking bobbin. main PCB by using a multimeter. If
there is no signal(220 VAC), replace
the main PCB.
The locking pin does not move in Check the locking mechanism.
its insert.
8)The lid lock pin is The locking mechanism is Check the locking mechanism.
not released at defective.
the end of
sterilization The locking bobbin is defective. Replace the locking bobbin.
cyclealthough the
pressure in the The main PCB does not send any Check locking bobbin output of the
chamber drops to signal to the locking bobbin. main PCB by using a multimeter. If
zero. there is no signal(220 VAC), replace
the main PCB.
Pressure switch is defective. Check whether 14.01 pressure switch
is defective. If it is defective, replace
it.
11
FAILURE PROBABLE CAUSES SOLUTION
3)“Error 03”appears The measured temperature by Check the chamber, the load and the
on the display. PT-1, PT-2 or PT-3 sensor has jacket temperature sensors or main
exceeded limit temperature PCB terminals are loosen or broken.
(170⁰C).
If these are defective, replace them.
4)“Error 04”appears PT-1 or PT-2 reads the value Check the chamber, the load and the
on the display. exceeding +4 ⁰C of the set value jacket temperature sensors or main
(for melting program SET+10⁰C). PCB terminals are loosen or broken.
If these are defective, replace them.
SSR of gasket heater sends signal Check whether SSR of gasket heater
continuously to the heater. is defective.
5) “Error 05”appears The temperature has not increased by 5ºC during 60 minutes after
on the display. heating phase has started.
Main PCB does not send any Check SSR output of the main PCB by
signal to SSRs of heaters. using a multimeter. If there is no
signal(12 V DC), replace the main
PCB.
12
FAILURE PROBABLE CAUSES SOLUTION
6) “Error 06”appears on the The temperature value of PT-1 for solid or PT-2 for liquid
display. decreases 2⁰C below the set temperature (for melting
program -10⁰C) after the sterilization process has started.
Main PCB does not send any Check whether main PCB
signal to the locking bobbin. sends signal to locking
bobbin.
13
FAILURE PROBABLE CAUSES SOLUTION
9) “Error 09”appears on the The maximum temperature for pre-heating is exceeded.
display.
SSR of gasket heater is Replace this SSR.
defective.
Main PCB is defective. Check SSR outputs of the
main PCB by using a
multimeter. If there is no
signal (12 V DC), replace the
main PCB.
10) “Error 10”appears on the There is no water in the Add water up to top of the
display. chamber. grid in the chamber.
11) “Error 11”appears on the Pt-3 sensor is broken Check whether input of the
display. temperature sensor of the
gasket is not looser. If sensor
is broken, change it.
12) “Error 12”appears on the Door is open when the device is turned on.
display.
Door switch is defective. Check whether door switch is
defective.
Main PCB is defective. Replace main PCB.
13) “Error 13”appears on the Drain water tank is removed from its place at stand-by or
display. running positions.
14
3.4. SSR CONTROL
SSR has 4 terminals (Figure 2). Terminal 1 and 2 are used for phase flow, Terminal 3 and 4 are
connected to the main PCB. Terminal 3 is connected to the (+) end and terminal 4 is connected
to the (-) end. Terminal 1 is the phase inlet and terminal 2 is the phase outlet.
DC voltage supplied by SSR to the Terminal 3 and 4 enable phase flow by causing short circuit on
the terminal 1 and 2. If there is no voltage on Terminal 3 and 4, terminal 1 and 2 are open
circuit.
State - 1: There is voltage on the main card and Terminal 1 and 2 are open circuit,
State - 2: There is no voltage on the main card and Terminal 1 and 2 are short circuit.
At State-1, if a heater is connected to Terminal 2, the unit does not heat or if a cooling element
is connected to Terminal 2, the unit does not cool.
At State-2, if a heater is connected to Terminal 2, the unit cannot control the heating and it
overheats. If a cooling element is connected to Terminal 2, the unit cannot control cooling and
overcooling is observed in the unit.
Controlling State-1:
When the device is on the OFF position, disconnect Terminal 1 from the main card. The terminal
of the cable must not touch to anywhere, please isolate it.
If the unit does not heat, set it to high temperature and run it. Check Terminal 3 and 4 whether
there is DC voltage or not. If there is DC voltage, it means that the main card works properly. In
this case, check Terminal 1 and 2 whether there is short circuit. If there is no short circuit but
there is open circuit, it means SSR is defective. SSR is not defective on the following situations:
Repeat the same procedure after setting the temperature to a low temperature in order to
control the SSR in the case where the unit does not cool.
15
Controlling State-2:
When the device is on the OFF position, disconnect Terminal 1 from the main card. The terminal
of the cable must not touch to anywhere, please isolate it.
If overheating problem is encountered, set the temperature to a value smaller than the
displayed one or do your measurements after temperature exceeds the set temperature value.
Check whether there is DC voltage on Terminal 3 and 4. If there is no DC voltage, the main card
does not work properly. In this case, check Terminal 1 and 2 whether there is open circuit. If
there is no open circuit but there is short circuit, then SSR is defective. SSR is not defective on
the following situations:
In case of overcooling, repeat the same procedure to control the SSR but set the temperature to
a high temperature value or do the measurements after temperature drops below the set value.
Remove the right sheet for servicing procedure about manometer, door switch, safety valve, Pt-
3 (jacket temperature sensor) and the left sheet for the other servicing procedures. Remove two
screws located at the bottom of the sheet and take the sheet out.
16
Pressureswitch
Steam trap
Solenoidvalve
Chamber
Main PCB
Door Switch
Figure8: Leftside Switch relay
Manometer
Safety Valve
Pt-3
(Jacket temperature sensor)
Heater
connection nuts
17
4.1. REPLACING MAIN PCB
SSR output
Temperature
Sensor output
Figure10
• Disconnect the connection cable between temperature display PCB and main PCB from the
main PCB.
• Remove all the terminals (ie. SSR, temperature sensor) connected to terminals of main PCB.
• Remove 4 clamps located on the main display and take the display PCB out.
• Put the new display PCB on its place and make the terminal connections according to the
electrical diagram (See Section 5.)
• Fix connection cable between temperature display PCB and main PCB to the new main PCB.
Nut
Connection cable
Figure11
18
• Disconnect the connection cable between display PCB and main PCB from the display PCB.
• Remove 4 nuts located on the display PCB and take the display out.
• Put the new display PCB on its place and check that the display keys and the leds meet their
places on the panel.
• Make the terminal connections according to the electrical diagram (See Section 5.)
• Fix connection cable between display PCB and main PCB to the new display PCB.
4.3.1. PT-1
Heaters
PT-1
Safety
thermostat
probe
Figure12:PT-1 Sensor
• Disconnect the terminals of Pt-1 from the main PCB.
• Remove the nut located at the bottom of the chamber by using wrench and take the sensor
out. (See Figure 13)
PT-1
Figure13
• Apply liquid gasket* on the thread of the temperature sensor to provide any leakage and
place the new temperature sensor.
• Make the terminal connections of temperature sensor according to the electrical diagram
(See Section 5)
Nut
4.3.2. PT-2
PT-2
Figure14:PT-2 Sensor
• Disconnect the terminals of Pt-2 from the main PCB.
• Remove the nut located on the lid by using wrench and pull the sensor out.
• Apply liquid gasket* on the thread of the temperature sensor to provide any leakage and
place the new temperature sensor.
4.3.3. PT-3
PT-3
20
• Disconnect the terminals of the temperature sensor from the main PCB.
• Remove the two clamps located on the chamber (See figure 28) and separate Pt-3 from the
chamber.
• Remove the temperature sensor from the chamber.
• Placethe new sensor on the chamber.
• Make the terminal connections of temperature sensor according to the electrical diagram
(See Section 5)
• Remove screw of the solenoid valve socket and separate it from the solenoid valve.
• Remove the connection adaptors. (See Figure 16)
• Take the solenoid valve out.
• Fix the connection adaptors to output and input of the new solenoid valve.
• Assemble the new solenoid valve.
• Fix the hoses of the solenoid valve.
• Assemble the solenoid valve socket carefully.
Steam trap
Solenoidvalvesocket
Solenoidvalve
Connection adaptor
Solenoidvalvehoses
Figure16
21
4.5. REPLACING SSR
Screw
Figure17
Vacuum breaker
Nut
Safety Valve
Figure18
22
4.7. REPLACING CHAMBER GASKET
Safety thermostat
nut
Nut
Figure19
23
4.9. REPLACING SAFETY THERMOSTAT
Safety Thermostat
Connection Screw
Figure20
Safety
Thermostat
clamp
Figure21
24
4.10. REPLACING COOLING FAN
Screw
Electrical connections
Figure22
Locking bobbin
Connection screw
Figure23
25
4.12. REPLACING DOOR SWITCH
Door switch
Nut
Locking bobbin
Figure24
Nuts
Surface thermostat
Electrical connnections
Figure25
26
4.14. REPLACING PRESSURE SWITCH
Connection union
Pressure switch
Figure26
• Disconnect terminals of the pressure switch.
• Remove the connection union of defective pressure switch.
• Assemble the new pressure switch.
• Make the terminal connections according to the electrical diagram.(See section 5)
Steam Trap
Connection hose
Figure27
27
• Remove the hose of the steam trap.
• Take steam trap out.
• Assemble new steam trap.
• Fix the hose of the steam trap.
Clamp
Figure28
Hose
Screw
Nut
Figure29
28
4.18. REPLACING SWITCH OF DRAIN WATER TANK
Terminals
Screw
Figure 30 Figure 31
29
5. ELECTRICAL CIRCUIT DIAGRAM
30
6. SPARE PARTS LIST
31