Mitsubishi Electric PU-P71VHA Service Manual page 34

Error Code Meaning of error code and detection method
Open/short circuit of discharging ther-
mistor (TH4)
Abnormal if open (0: or less) or short
(216: or more) is detected during com-
U3
pressor operation.
(5104)
(Detection is inoperative for five minutes of
compressor starting process and for 10
minutes after defrosting.)
Open/short circuit of the liquid pipe
thermistor (TH3) or outdoor Condenser-
Evaporator pipe thermistor (TH6)
U4
Abnormal if open (-39: or less) or short
(5105)
(88: or more) is detected during com-
(5107)
pressor operation.
(Detection is inoperative for seven minutes
after 10 seconds of compressor starting
and for 10 minutes after defrosting.)
Compressor over current (overload)
breaking
Abnormal if current value exceeds over-
U6 load set value during compressor opera-
tion.
(4101)
P71V 23.5A
• • •
P100V 28.5A
• • •
P125Y 12.6A
• • •
Thermal relay (51C) worked
Abnormal if 51C is open.
UA
(4101)
Over heat protection (over-load opera-
tion protection/abnormal fan)
Abnormal if pipe thermistor detects the
Ud
value that exceeds set value during com-
(1504)
pressor operation.
P71-P140 70:
• • •
Abnormal High pressure
This error is detected (4.14MPa) from 63H
action within 20 seconds of compressor
starting in the first heating mode after
power on.
63H: high-pressure switch
UE
(1302)
Abnormal low pressure (63L worked)
Abnormal if connector (63L) is open
(under- 0.03MPa) during compressor oper-
ation.
UL
(1300)
1 Disconnection or contact failure
of connector (TH4) on the
indoor controller board.
2 Defective thermistor
3 Defective outdoor controller
board
1 Disconnection or contact failure
of connector (TH3/TH6) on the
indoor controller board.
2 Defective thermistor
3 Defective outdoor controller
board
1 Gas pipe side ball valve and
liquid pipe side stop valve are
shut during operation.
2 Abnormal compressor
3 Abnormal power supply voltage
P71Y 7.8A 4 Overload operation
• • •
P100Y 9.4A
• • •
P140Y 15.6A
• • •
1 Ball valve and stop valve are
closed during operation.
2 Abnormal compressor
3 Abnormal power supply volt-
age
4 Short interruption.
1 In cooling mode: defective
outdoor fan (fan motor) or
short cycle of air path
2 Defective thermistor
3 Defective outdoor controller
board
1 Gas pipe side ball valve and
liquid pipe side stop valve are
shut during operation.
2 Disconnection or contact failure
of 63H
3 Defective outdoor controller board
4 Power supply reset is detected
while indoor filter clogs and
overload heating operation.
5 Defective outdoor controller
board
6 Defective action of linear
expansion valve
1 Gas pipe side ball valve and
liquid pipe side stop valve are
shut during operation.
2 Disconnection or contact fail-
ure of connector (63L) on out-
door controller board.
3 Disconnection or contact fail-
ure of 63L.
4 Defective outdoor controller
board
5 Leakage or defective of refrig-
erant
6 Defective action of linear
expansion valve
Case
1 Check contact of connector (TH4) on the
indoor controller board.
Refer to 10-7
Check breaking of the lead wire for thermistor
(TH4). Refer to 10-6
2 Check resistance value of thermistor
(Refer to 10-6.), or check temperature by
microcomputer(Mode switch of SW2).
3 Replace outdoor controller board.
1 Check contact of connector (TH3/TH6) on
the indoor controller board.
Refer to 10-7.
Check breaking of the lead wire for thermistor
(TH3/TH6). Refer to 10-6.
2 Check resistance value of thermistor
(Refer to 10-6.), or check temperature by
microcomputer(Mode switch of SW2).
3 Replace outdoor controller board.
1 Open ball valve and stop valve.
2 Check or replace compressor.
Refer to 5-2.
3 Check power supply voltage.
4 Check short cycle.
1 Open ball valve and stop valve.
2 Check or replace compressor.
Refer to 5-2.
3,4Check power supply voltage.
1 Check outdoor fan (fan motor)
Refer to 10-6.
24 Put the power off and operate again to
check if U4 is displayed.
If U4 is displayed, follow the U4 process-
ing direction.
1 Open ball valve and stop valve.
23 Put the power off, and operate again to
check if F5 is displayed.
If F5 is displayed, follow the F5 processing
direction.
4 Check indoor filter.
5 Replace outdoor controller board.
6 Check linear expansion valve.
Refer to 10-6.
1 Open ball valve and stop valve.
234 Put the power off and on again to check
if F3 is displayed on restarting.
If F3 is displayed, follow the F3 process-
ing direction.
5 Leakage or defective of refrigerant
6 Check linear expansion valve
Refer to 10-6.
34
Judgment and action