Mitsubishi Electric PUHZ-FRP71VHA2 Service Manual page 58

Indication
Outdoor controller board
LED1 (Green) LED2 (Red)
3 blinking 1 blinking Abnormality of comp. surface
thermistor (TH33) and discharging
temperature (TH4)
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 heatsink
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.
OCH665B
Check
Contents
code
U2
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) 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 reverse 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 (CN6) 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 reverse
connection of compressor wiring.
2Measure resistance value among terminals on
compressor using a tester.
3Check if power supply voltage decreases.
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.
1Reverse 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 reverse connection of extension pipe. (on
plural units connection)
4Check if indoor/outdoor connecting wire is connected
correctly. (on plural units connection)
58
Detailed
reference page
P.28
P.28
P.29
P.31
P.31
P.31
P.31
P.28
P.28
P.29
P.29
P.30
*2
*2
*2
*2
*2
*2
*2
*2