Och636A - Mitsubishi Electric PUZ-A12NKA7 Service Manual

Indication Error
Outdoor controller board
Contents
LED (Green) LED2 (Red)
2 blinking 5 blinking Serial communication error
<Communication between outdoor
controller board and outdoor power board>
<Communication between outdoor
controller board and M-NET P.C. board>
Communication error of M-NET system A0–A8
3 blinking 1 blinking Abnormality of shell thermistor
(TH32)
and discharging temperature (TH4)
2 blinking Abnormal high pressure (High
pressure switch 63H operated.)
3 blinking Abnormality of outdoor fan
motor rotational speed
4 blinking Compressor overcurrent breaking
(Startup locked)
Compressor overcurrent breaking
Abnormality of current sensor (P.B.)
Abnormality of power module
5 blinking Open/short of discharge thermistor (TH4)
Open/short of outdoor thermistors
(TH3, TH6, TH7, TH8, and TH33)
6 blinking Abnormality of Heat sink
temperature
7 blinking Abnormality of voltage
4 blinking 1 blinking Abnormality of room temperature thermistor (TH1)
Abnormality of pipe temperature
thermistor/Liquid (TH2)
Abnormality of pipe temperature
thermistor/Condenser-Evaporator (TH5)
2 blinking Abnormality of drain sensor (DS)
Float switch connector open(FS)
Indoor drain overflow protection
3 blinking
Freezing (cooling)/overheating
(heating) protection
4 blinking
Abnormality of pipe
temperature
5 blinking Abnormality of indoor controller
board
Inndoor fan motor trouble
Abnormality of remote controller
― ―
board
*1 Check code displayed on remote controller
*2 Refer to the indoor unit service manual.

OCH636A

Check
Inspection method
1
code*
1 Check if connector (CN4) on outdoor controller board and outdoor
power board is not disconnected.
Ed
2 Check if there is poor connection of connector on outdoor
controller board(CNMNT and CNVMNT).
3 Check M-NET communication signal.
1 Check if stop valves are open.
2 Check if connectors (TH4, TH33, LEV-A, and LEV-B) on outdoor
controller board are not disconnected.
U2
3 Check if unit is filled with specified amount of refrigerant.
4 Measure resistance values among terminals on indoor valve and
outdoor linear expansion valve using a tester.
1 Check if indoor/outdoor units have a short cycle on their air ducts.
2 Check if connector (63H) on outdoor controller board is not disconnected.
U1
3 Check if heat exchanger and filter is not dirty.
4 Measure resistance values among terminals on linear expansion
valve using a tester.
1 Check the outdoor fan motor.
U8
1 Check if stop valves are open.
UF
2 Check looseness, disconnection, and converse connection of compressor wiring.
UP
3 Measure resistance values among terminals on compressor using a tester.
UH
4 Check if outdoor unit has a short cycle on its air duct.
U6
U3
1 Check if connectors (TH3, TH4, TH6, TH7 and TH32) on outdoor controller
board and connector (CN3) on outdoor power board are not disconnected.
U4
2 Measure resistance value of outdoor thermistors
1 Check if indoor/outdoor units have a short cycle on their air ducts.
U5
2 Measure resistance value of outdoor Heat sink thermistor(TH8).
1 Check looseness, disconnection, and converse connection of
compressor wiring.
2 Measure resistance value among terminals on compressor using a tester.
U9
3 Check the continuity of contactor (52C).
4 Check if power supply voltage decreases.
5 Check the wiring of CN52C.
6 Check the wiring of CNAF.
P1 1 Check if connectors (CN20, CN21, CN29, and CN44) on indoor
controller board are not disconnected.
P2
2 Measure resistance value of indoor thermistors.
P9
1 Check if connector (CN31)(CN4F) on indoor controller board is not disconnected.
P4
2 Measure resistance value of indoor thermistors.
3 Measure resistance value among terminals on drain pump using a tester.
P5
4 Check if drain pump works.
5 Check drain function.
1 Check if indoor unit has a short cycle on its air duct.
2 Check if heat exchanger and filter is not dirty.
P6
3 Measure resistance value on indoor and outdoor fan motors.
4 Check if the inside of refrigerant piping is not clogged.
1 Check if indoor thermistors (TH2 and TH5) are not disconnected from holder.
2 Check if stop valve is open.
P8
3 Check converse connection of extension pipe. (on plural units connection)
4 Check if indoor/outdoor connecting wire is connected correctly. (on plural units connection)
1 Replace indoor controller board.
Fb
Pb
1 Check the winding of an indoor unit fan motor.
E1
1 Replace remote controller.
E2
74
Detailed
reference
page
P.38
P.39–P.41
P.33
P.33
P.34
P.36
P.36
P.36
P.34
P.34
P.34
P.34
P.35
*2
*2
*2
*2
*2
*2
*2
*2
*2
P.37