Mitsubishi Electric PUZ-ZM60VHA2 Service Manual page 78

Indication
Outdoor controller
board
LED1 (Green) LED2 (Red)
3 blinking 1 blinking Abnormality of comp. surface
thermistor (TH33) and
discharge temperature (TH4)
Abnormality of superheat due
to low discharge temperature
2 blinking Abnormal high pressure (High
pressure switch 63H operated.)
3 blinking Abnormality of outdoor fan
motor rotational speed
Protection from overheat operation(TH3)
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)
and comp. surface thermistor (TH33)
Open/short of outdoor thermistors
(TH3, TH6, TH7 and TH8)
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
2 blinking Abnormality of drain sensor (DS)
Float switch(FS) connector open
Indoor drain overflow protection
Leakage error (refrigerant system)
3 blinking Freezing (cooling)/overheating
(heating) protection
4 blinking Abnormality of pipe
temperature
5 blinking Indoor unit fan motor error
*1 Check code displayed on remote controller
*2 Refer to the indoor unit's service manual.
OCH771
Check
Contents
code
U2
U7
U1
U8
Ud
UF
UP
UH
U6
U3
U4
U5
U9
P1
P2
P9
P4
P5
PA
P6
P8
PB(Pb) Defective fan motor winding
Error
Inspection method
*1
1Check if stop valves are open.
2Check if connectors (TH4, TH33, LEV-A, and LEV-B)
on outdoor controller board are not disconnected.
3Check if unit is filled with specified amount of refrigerant.
4Measure resistance values among terminals on indoor valve
and outdoor linear expansion valve using a tester.
1Check if indoor/outdoor units have a short cycle on their air ducts.
2Check if connector (63H and TRS) on outdoor
controller board is not disconnected.
3Check if heat exchanger and filter is not dirty.
4Measure resistance values among terminals on
linear expansion valve using a tester.
1Check the outdoor fan motor.
2Check if connector (TH3) on outdoor controller
board is disconnected.
1Check if stop valves are open.
2Check looseness, disconnection, and reversed
connection of compressor wiring.
3Measure resistance values among terminals on
compressor using a tester.
4Check if outdoor unit has a short cycle on its air duct.
1Check if connectors(TH3,TH4,TH6 ,TH7 and TH33) on
outdoor controller board and connector (CN3) on outdoor
power board are not disconnected.
2Measure resistance value of outdoor thermistors.
1Check if indoor/outdoor units have a short cycle on their air ducts.
2Measure resistance value of outdoor thermistor(TH8).
1Check looseness, disconnection, and reversed
connection of compressor wiring.
2Measure resistance value among terminals on
compressor using a tester.
3Check if power supply voltage decreases.
4Check the wiring of CN52C.
1Check if connectors (CN20, CN21, CN29 and
CN44) on indoor controller board are not
disconnected.
2Measure resistance value of indoor thermistors.
1Check if connector (CN31)(CN4F) on indoor
controller board is not disconnected.
2Measure resistance value of indoor thermistors.
3Measure resistance value among terminals on
drain pump using a tester.
4Check if drain pump works.
5Check drain function.
1Reversed connection of piping or wiring
Note: The error will be cancelled by turning off
power, and on again.
2Check if there are any inclination or clogging in
drain pipe.
3Check if drain pan or drain sensor is dirty.
4Check if any foreign matter is attached to the
moving part of float switch.
5Check LEV for proper function.
1Check if indoor unit has a short cycle on its air duct.
2Check if heat exchanger and filter is not dirty.
3Measure resistance value on indoor and outdoor fan
motors.
4Check if the inside of refrigerant piping is not clogged.
1Check if indoor thermistors(TH2 and TH5) are not
disconnected from holder.
2Check if stop valve is open.
3Check reversed connection of extension pipe. (on
plural units connection)
4Check if indoor/outdoor connecting wire is
connected correctly. (on plural units connection)
78
Detailed
reference
page
P. 41
P. 42
P. 41
P. 42
P. 44
P. 44
P. 45
P. 44
P. 42
P. 41
P. 42
P. 42
P. 43
–P. 44
*2
*2
*2
*2
*2
*2
*2
*2
*2