Mitsubishi Electric PUHZ-HRP71VHA Service Manual page 67

Indication
Outdoor controller board
LED1 (Green) LED2 (Red)
3 blinking 1 blinking
Abnormality of shell thermostat
and discharging temperature (TH4)
Abnormality of superheat due
to low discharge temperature
Abnormal high pressure (High
2 blinking
pressure switch 63H worked.)
Abnormal low pressure (Low
pressure switch 63L worked.)
3 blinking
Abnormality of outdoor fan
motor rotational speed
Protection from overheat operation(TH3)
Compressor overcurrent
4 blinking
breaking(Start-up locked)
Compressor overcurrent breaking
Abnormality of current sensor (P.B.)
Abnormality of power module
Open/short of discharge thermistor (TH4)
5 blinking
Open/short of outdoor thermistors
(TH3, TH32, TH33, 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 connector open (FS)
Indoor drain overflow protection
3 blinking
Freezing (cooling)/overheating
(heating) protection
4 blinking Abnormality of pipe
temperature
1 Error code displayed on remote controller
2 Refer to service manual for indoor unit.
Error
Contents
code
1
Check if stop valves are open.
U2
Check if connectors (TH4, LEV-A, and LEV-B) on outdoor controller
board are not disconnected.
Check if unit is filled with specified amount of refrigerant.
U7
Measure resistance values among terminals on indoor valve and
outdoor linear expansion valve using a tester.
Check if indoor/outdoor units have a short cycle on their air ducts.
U1
Check if connector(63H)(63L) on outdoor controller board is not disconnected.
Check if heat exchanger and filter is not dirty.
Measure resistance values among terminals on linear expansion valve
UL
using a tester.
U8
Check the outdoor fan motor.
Check if connector (TH3) on outdoor controller board is disconnected.
Ud
Check if stop valves are open.
UF
Check looseness, disconnection, and converse connection of
compressor wiring.
Measure resistance values among terminals on compressor using a tester.
UP
Check if outdoor unit has a short cycle on its air duct.
UH
U6
Check if connectors(TH3,TH32,TH33,TH4, and TH7/6)on outdoor
U3
controller board and connector (CN3) on outdoor power board are not
U4
disconnected.
Measure resistance value of outdoor thermistors.
Check if indoor/outdoor units have a short cycle on their air ducts.
U5
Measure resistance value of outdoor thermistor(TH8).
U9 Check looseness, disconnection, and converse connection of
compressor wiring.
Measure resistance value among terminals on compressor using a tester.
Check if power supply voltage decreases.
Check the wiring of CN52C.
Check the wiring of CNAF.
Check if connectors (CN20, CN21, CN29 and CN44) on indoor
P1
controller board are not disconnected.
P2
Measure resistance value of indoor thermistors.
P9
P4 Check if connector (CN31)(CN4F) on indoor controller board is not
disconnected.
Measure resistance value of indoor thermistors.
Measure resistance value among terminals on drain-up machine using
P5
a tester.
Check if drain-up machine works.
Check drain function.
P6
Check if indoor unit has a short cycle on its air duct.
Check if heat exchanger and filter is not dirty.
Measure resistance value on indoor and outdoor fan motors.
Check if the inside of refrigerant piping is not clogged.
P8 Check if indoor thermistors(TH2 and TH5) are not disconnected from holder.
Check if stop valve is open.
Check converse connection of extension pipe. (on plural units connection)
Check if indoor/outdoor connecting wire is connected correctly.
(on plural units connection)
Error
Inspection method
67
Detailed
reference
page
P.31
P.32
P.31
P.34
P.33
P.33
P.34
P.33
P.32
P.31
P.32
P.32
P.33
2
2
2
2
2
2