Mitsubishi Electric PUHY-HP200 Service Handbook page 132

[ IX Troubleshooting ]
1. Error Code
1302
High pressure fault 1 (Outdoor unit)
2. Error definition and error detection method
1) If the pressure of 3.78MPa [548psi] or higher is detected by the pressure sensor during operation (the first detection), the out-
door stops once, turns to antirestart mode for 3 minutes, and restarts after 3 minutes automatically.
2) If the pressure of 3.78MPa [548psi] or higher is detected by the pressure sensor again (the second detection) within 30 min-
utes after the first stop of the outdoor unit, the outdoor unit stops once, turns to anti-restart mode for 3 minutes, and restarts
after 3 minutes automatically.
3) If the pressure of 3.87MPa [561psi] or higher is detected by the pressure sensor (the third detection) within 30 minutes of the
second stop of the outdoor unit, the outdoor unit will make an error stop, and the error code "1302" will be displayed.
4) If the pressure of 3.78MPa [548psi] or higher is detected more than 30 minutes after the stop of the outdoor unit, the detection
is regarded as the first detection, and the operation described in step 1 above will start.
5) For 30 minutes after the stop of the outdoor unit, preliminary errors will be displayed on the LED display.
6) The outdoor unit makes an error stop immediately when not only the pressure sensor but also the pressure switch detects
+0,-0.15 +0,-22
4.15 MPa [601
7) Open phase due to unstable power supply voltage may cause the pressure switch to malfunction or cause the units to come
to an abnormal stop.
3. Cause, check method and remedy
(1) Outdoor unit LEV2a, 2b actuation failure -> Cooling
Indoor unit LEV actuation failure -> Heating
(2) Closed refrigerant service valve
(3) Short cycle on the indoor unit side
(4) Clogged filter on the indoor unit
(5) Reduced air flow due to dirty fan on the indoor unit
fan
(6) Dirty heat exchanger of the indoor unit
(7) Indoor fan (including fan parts) failure or motor fail-
ure
Rise in high pressure caused by lowered condens-
ing capacity in heating operation for (2) - (7).
(8) Short cycle on the outdoor unit
(9) Dirty heat exchanger of the outdoor unit
(10) Outdoor fan (including fan parts) failure, motor fail-
ure, or fan controller malfunction
Rise in discharge temp. by low pressure drawing
for (8) - (10).
(11) Solenoid valve (SV1a) malfunction (The by-pass
valve (SV1a) can not control rise in high pressure).
(12) Thermistor failure (TH3, TH7)
(13) Pressure sensor failure
(14) Failure of the thermistor input circuit and pressure
sensor input circuit on the controller board
(15) Thermistor mounting problem (TH3, TH7)
(16) Disconnected male connector on the pressure
switch (63H1) or disconnected wire
(17) Voltage drop caused by unstable power supply
voltage
HWE08110
psi]
Cause Check method and remedy
Perform a cooling or heating operation to check the opera-
tion.
Cooling: Indoor unit LEV
LEV1, 2a, 2b
Heating: Indoor unit LEV
LEV2a, 2b
Refer to the section on troubleshooting the LEV.(page 191)
Confirm that the refrigerant service valve is fully open.
Check the indoor units for problems and correct them, if any.
Check the outdoor units for problems and correct them, if
any.
Check the fan on the outdoor unit.
Refer to the section on troubleshooting the outdoor unit
fan.(page 190)
Refer to the section on troubleshooting the solenoid
valve.(page 189)
Check the thermistor resistor.(page 142)
Refer to the page on the troubleshooting of the high pres-
sure sensor. (page 187)
Check the temperature and the pressure of the sensor with
LED monitor.
Check the temperature and the pressure of the sensor with
LED monitor.
Check the input voltage at the power supply terminal block
(TB1).
- 123 - GB