Mitsubishi Electric PUHZ-SHW230YKA2 Service Manual page 42

Indication
Outdoor controller board
LED1 (Green) LED2 (Red)
3 blinking 1 blinking
Abnormality of comp. surface
temperature (TH34) and discharging
temperature (TH4)
Abnormality of superheat due
to low discharge temperature
Abnormal high pressure (High
2 blinking
pressure switch 63H operated.)
Abnormal low pressure (Low
pressure switch 63L operated.)
3 blinking Abnormality of outdoor fan
motor rotational speed
Protection from overheat operation
(TH3), (T
Compressor overcurrent
4 blinking
breaking(Startup locked)
Compressor overcurrent breaking
Abnormality of current sensor (P.B.)
Abnormality of power module
5 blinking Open/short of outdoor thermistors
(TH4, TH34)
Open/short of outdoor thermistors
(TH3, TH32, TH6, TH7 and TH8)
Abnormality of heat sink
6 blinking
temperature
7 blinking Abnormality of voltage
4 blinking 1 blinking
Abnormality of water temperature thermistor (TH1)
Abnormality of pipe temperature thermistor / Liquid (TH2)
Abnormality of actual tank temperature thermistor
(TH5)
3 blinking Freezing (cooling)/overheating
(heating, heating ECO,
anti freeze, hot water) protection
* 1 Check code displayed on remote controller
* 2 Refer to Technical manual of ATW, I/F, FTC.
OCH594B
Check
Contents
code
*
U2
U7
U1
UL
U8
Ud
)
63HS
UF
UP
UH
U6
U3
U4
U5
U9
P1
P2
P9
P6
Error
Inspection method
1
1Check if stop valves are open.
2Check if connectors (TH4, TH34, 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 outdoor unit have a short cycle on their air ducts.
2Check if connector (63H)(63L) 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) (63HS) 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.
5Check leakage of refrigerant.
1Check if connectors (TH3,TH32,TH4, TH34 and TH7/6) on outdoor
controller board and connector (CN3) on outdoor power board are not
disconnected.
2Measure resistance value of outdoor thermistors.
1Check if outdoor unit 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 terminal on I/F or FTC are not disconnected.
2Measure resistance value of I/F or FTC thermistors.
1Check if short cycle of air path.
2Check if heat exchanger and filter is not dirty.
3Measure resistance value on outdoor fan motor.
4Check if the inside of refrigerant piping is not clogged.
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