Mitsubishi Electric CITY MULTI PUHY-P108 Service Handbook page 251

[ IX Troubleshooting ]
Error Code
1302 Abnormal high
pressure 1
(outdoor unit)
Abnormal high
pressure 2
(outdoor unit)
Error definition and error
detection method
(1) LEV failure on the indoor
1. If the pressure of 3.87MPa
[561psi] or higher is detect-
ed by the pressure sensor
during operation (the first
detection), the outdoor
stops once, turns to anti-
restart mode for 3 minutes,
(2) Closed ball valve
and restarts after 3 min-
utes automatically.
2. If the pressure of 3.87MPa
(3) Short cycle on the indoor unit
[561psi] or higher is detect-
ed by the pressure sensor
(4) Clogged filter on the indoor unit
again (the second detec-
(5) Reduced air flow due to dirty fan
tion) within 30 minutes af-
ter the first stop of the
(6) Dirty heat exchanger of the in-
outdoor unit, the outdoor
unit stops once, turns to
(7) Indoor fan (including fan parts)
anti-restart mode for 3 min-
utes, and restarts after 3
minutes automatically.
3. If the pressure of 3.87MPa
[561psi] or higher is detect-
ed by the pressure sensor (8) Short cycle on the outdoor unit
(the third detection) within (9) Dirty heat exchanger of the out-
30 minutes of the second
stop of the outdoor unit, the
(10) Outdoor fan (including fan
outdoor unit will make an
error stop, and the error
code "1302" will be dis-
played.
4. If the pressure of 3.87MPa
[561psi] or higher is detect-
(11) Solenoid valve (SV1) malfunc-
ed more than 30 minutes
after the stop of the out-
door unit, the detection is
regarded as the first detec-
(12) Thermistor failure
tion, and the operation de-
scribed in step 1 above will
start.
(13) Pressure sensor failure
5. For 30 minutes after the
stop of the outdoor unit,
preliminary errors will be
displayed on the LED dis-
(14) Failure of the thermistor
play.
6. The outdoor unit makes an
error stop immediately
when not only the pressure
sensor but also the pres-
sure switch detects
(15) Faulty mounting of thermistor
+0,-0.15 +0,-22
4.15 MPa [601
psi]
(16) Disconnected male connector
(17) Melted fuse (F1 or F2) on
If the pressure of (1) Inner pressure drop due to a
0.098MPa [14psi] or low-
(2) Pressure sensor failure
er is registered on the
(3) Shorted-circuited pressure
pressure sensor immedi-
ately before start-up, it
will trigger an abnormal
(4) A pin on the male connector
stop, and error code
"1302" will be displayed.
(5) Disconnected pressure sen-
(6) Failure of the pressure sen-
Cause
unit
-> Heating
side
on the indoor unit fan
door unit
failure or motor failure
Rise in high pressure caused by
lowered condensing capacity in
heating operation for (2) - (7).
door unit
parts) failure, motor failure, or
fan controller malfunction
Rise in discharge temp. by low
pressure drawing for (3) - (6).
tion (The by-pass valve (SV1)
can not control rise in high pres-
sure).
(TH5, TH6).
input circuit and pressure
sensor input circuit on the
controller board
(TH5, TH6)
on the pressure switch (63H) or
disconnected wire
the controller board
leakage.
sensor cable due to torn out-
er rubber
on the pressure sensor is
missing or contact failure
sor cable
sor input circuit on the con-
troller board
- 242 -
Check method and remedy
Perform a heating operation and
check the operation.
Heating : LEV on the indoor unit
Refer to the page on troubleshooting
LEV.
Confirm that the ball valve is fully
open.
Check the indoor units for problems
and correct them, if any.
Check the fan on the outdoor unit.
Refer to the section on troubleshoot-
ing the outdoor unit fan.
Refer to the section on troubleshoot-
ing the solenoid valve.
Check the thermistor resistor.
Refer to the page on the trouble-
shooting of the high pressure sen-
sor.
Check the temperature and the pres-
sure of the sensor with LED monitor.
Check the temperature and the pres-
sure of the sensor with LED monitor.
Check for a melted fuse.Check for short-cir-
cuited cooling FAN (MF), 4-way valve, or
actuator like solenoid valve.
Refer to the page on the trouble-
shooting of the high pressure sen-
sor.