Mitsubishi Electric SEZ-KC25VA, Technical & Service Manual

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9
6
TROUBLESHOOTING
6-1. Cautions on troubleshooting
(1) Before troubleshooting, check the followings:
1
Check the power supply voltage.
2
Check the indoor/outdoor connecting wire for mis-wiring.
(2) Take care the followings during servicing.
1
Before servicing the air conditioner, be sure to first turn off the remote controller 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.
˚C
˚C
SIMPLE
PAR-21MAA
ON/OFF
FILTER
CHECK
OPERATION
CLEAR
TEST
TEMP.
MENU
BACK DAY MONITOR/SET
CLOCK
ON/OFF
B
C
A
E D
6-2. Self-check function
Wired remote controller
(1) Turn on the power.
(2) Press the [CHECK] button twice.
(3) Set refrigerant address with [TEMP] button
if system control is used.
(4) Press the [ON/OFF] button to stop the
self-check.
A A
CHECK button
B B
Refrigerant address
C C
TEMP button
D D
IC : Indoor unit
OC : Outdoor unit
E E
Check code
1
Check code Symptom Remark
P1 Intake sensor error
P2 Pipe (TH2) sensor error
P9 Pipe (TH5) sensor error
E6,E7 Indoor/outdoor unit communication error
P4 Drain sensor error
P5 Drain pump error
P6 Freeing/Overheating safeguard operation
EE Communication error between indoor and outdoor units
P8 Pipe temperature error
E0, E3~E5 Remote controller transmission error
E1, E2 Remote controller control board error
Fb Indoor unit control system error (memory error, etc.)
E9 Indoor/outdoor unit communication error (Transmitting error) (Outdoor unit)
UP Compressor overcurrent interruption
U3,U4 Open/short of outdoor unit thermistors
UF Compressor overcurrent interruption (When compressor locked)
U2 Abnormal high discharging temperature/49C worked/insufficient refrigerant
U1,Ud Abnormal high pressure (63H worked)/Overheating safeguard operation
U5 Abnormal temperature of heat sink
U8 Outdoor unit fan safeguard stop
U6 Compressor overcurrent interruption/Abnormal of power module
U7 Abnormality of super heat due to low discharge temperature
U9,UH Abnormality such as overvoltage or voltage shortage and abnormal synchronous signal to main circuit
/Current sensor error
Others Other errors (Refer to the technical manual for the outdoor unit.)
For details, check the LED display
of the outdoor controller board.
As for outdoor unit, refer to
service manual OC322.
• On wired remote controller.
1 Check code displayed in the LCD.
• For description of each check code, refer to the following table.