Mitsubishi Electric PUZ-ZM60VHA2, Service Manual

Page: 78 / 140

78
OCH771
Indication Error
Detailed
reference
page
Outdoor controller
board
Contents
Check
code *1
Inspection method
LED1 (Green) LED2 (Red)
3 blinking 1 blinking Abnormality of comp. surface
thermistor (TH33) and
discharge temperature (TH4)
U2
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.
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.
P. 41
Abnormality of superheat due
to low discharge temperature
U7 P. 42
2 blinking Abnormal high pressure (High
pressure switch 63H operated.)
U1
1
Check if indoor/outdoor units have a short cycle on their air ducts.
2
Check if connector (63H and TRS) on outdoor
controller board is not disconnected.
3
Check if heat exchanger and filter is not dirty.
4
Measure resistance values among terminals on
linear expansion valve using a tester.
P. 41
3 blinking Abnormality of outdoor fan
motor rotational speed
U8
1
Check the outdoor fan motor.
2
Check if connector (TH3) on outdoor controller
board is disconnected.
P. 42
Protection from overheat operation(TH3) Ud P. 44
4 blinking Compressor overcurrent
breaking(Startup locked)
UF
1
Check if stop valves are open.
2
Check looseness, disconnection, and reversed
connection of compressor wiring.
3
Measure resistance values among terminals on
compressor using a tester.
4
Check if outdoor unit has a short cycle on its air duct.
P. 44
Compressor overcurrent breaking UP P. 45
Abnormality of current sensor
(P.B.)
UH P. 44
Abnormality of power module U6 P. 42
5 blinking Open/short of discharge thermistor (TH4)
and comp. surface thermistor (TH33)
U3
1
Check if connectors(TH3,TH4,TH6 ,TH7 and TH33) on
outdoor controller board and connector (CN3) on outdoor
power board are not disconnected.
2
Measure resistance value of outdoor thermistors.
P. 41
Open/short of outdoor thermistors
(TH3, TH6, TH7 and TH8)
U4 P. 42
6 blinking Abnormality of heat sink
temperature
U5
1
Check if indoor/outdoor units have a short cycle on their air ducts.
2
Measure resistance value of outdoor thermistor(TH8).
P. 42
7 blinking Abnormality of voltage
U9
1
Check looseness, disconnection, and reversed
connection of compressor wiring.
2
Measure resistance value among terminals on
compressor using a tester.
3
Check if power supply voltage decreases.
4
Check the wiring of CN52C.
P. 43
–P. 44
4 blinking 1 blinking Abnormality of room temperature thermistor (TH1) P1
1
Check if connectors (CN20, CN21, CN29 and
CN44) on indoor controller board are not
disconnected.
2
Measure resistance value of indoor thermistors.
*2
Abnormality of pipe temperature thermistor /Liquid (TH2) P2
*2
Abnormality of pipe temperature thermistor/
Condenser-Evaporator
P9
*2
2 blinking Abnormality of drain sensor (DS)
Float switch(FS) connector open
P4
1
Check if connector (CN31)(CN4F) on indoor
controller board is not disconnected.
2
Measure resistance value of indoor thermistors.
3
Measure resistance value among terminals on
drain pump using a tester.
4
Check if drain pump works.
5
Check drain function.
*2
Indoor drain overflow protection
P5
*2
Leakage error (refrigerant system)
PA
1
Reversed connection of piping or wiring
Note: The error will be cancelled by turning off
power, and on again.
2
Check if there are any inclination or clogging in
drain pipe.
3
Check if drain pan or drain sensor is dirty.
4
Check if any foreign matter is attached to the
moving part of float switch.
5
Check LEV for proper function.
*2
3 blinking Freezing (cooling)/overheating
(heating) protection
P6
1
Check if indoor unit has a short cycle on its air duct.
2
Check if heat exchanger and filter is not dirty.
3
Measure resistance value on indoor and outdoor fan
motors.
4
Check if the inside of refrigerant piping is not clogged.
*2
4 blinking Abnormality of pipe
temperature
P8
1
Check if indoor thermistors(TH2 and TH5) are not
disconnected from holder.
2
Check if stop valve is open.
3
Check reversed connection of extension pipe. (on
plural units connection)
4
Check if indoor/outdoor connecting wire is
connected correctly. (on plural units connection)
*2
5 blinking Indoor unit fan motor error PB(Pb) Defective fan motor winding
*2
*1 Check code displayed on remote controller
*2
Refer to the indoor unit’s service manual.