Troubleshooting - Mitsubishi Mr.SLIM SLZ-KA25VAQ Technical & Service Manual

8

TROUBLESHOOTING

8-1. CAUTIONS ON TROUBLESHOOTING
(1) Before troubleshooting, check the followings:
1 Check the power supply voltage.
2 Check that the indoor/outdoor connecting wire is correct.
(2) Take care of the followings during servicing:
1 Before servicing the air conditioner, be sure to turn off the remote controller first to stop the main unit, and then turn
off the breaker.
2 When removing the indoor controller board, hold the edge of the board with care NOT to apply stress on the
components.
3 When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.
8-2. MALFUNCTION-DIAGNOSIS METHOD BY REMOTE CONTROLLER
Errors detected by indoor unit
Wired remote controller
Check code
P1
Intake sensor error
P2 Pipe (TH2) sensor error
P9 Pipe (TH5) sensor error
Indoor/outdoor unit communication error
E6,E7
P4 Drain sensor error
P5 Drain pump error
P6 Freezing/Overheating protection operation
PL Abnormal refrigerant circuit
EE Communication error between indoor and outdoor units
P8 Pipe temperature error
E4, E5 Remote controller signal receiving error
– –
– –
Fb (FB) *1 Indoor unit control system error (memory error,etc.)
Remote controller transmission error
E0, E3
E1, E2 Remote controller control board error
Errors detected by unit other than indoor unit (outdoor unit, etc.)
Wired remote controller
Check code
Indoor/outdoor unit communication error
E9
(Transmitting error) (Outdoor unit)
Compressor overcurrent interruption
UP
Open/short of outdoor unit thermistors
U3,U4
Compressor overcurrent interruption (When compressor locked)
UF
Abnormal high discharging temperature/49C operated/
U2
insufficient refrigerant
Abnormal high pressure (63H operated)/Overheating
U1,Ud (UD) *1
protection operation
Abnormal temperature of heatsink
U5
Outdoor unit fan protection stop
U8
Compressor overcurrent interruption/Abnormal of power module
U6
Abnormality of superheat due to low discharge temperature
U7
Abnormality such as overvoltage or voltage shortage and
U9,UH
abnormal synchronous signal to main circuit/Current sensor error
– –
– –
Others
Other errors (Refer to the technical manual for the outdoor unit.)
*1 The check code in the parenthesis indicates PAR-30MAA model.
OCH493D
Lead wire
Symptom
Symptom
12
Remark
Remark
For details, check
the LED display
of the outdoor
controller board.
As for outdoor
unit, refer to
outdoor unit's
service manual.
continued to the next page.