Table of Contents
Advertisement
11-5. TROUBLESHOOTING FLOW
A How to check inverter/compressor
MUZ-FD25/35
Disconnect the connector (CN61) between
compressor and the intelligent power module
(IPM).
Check the voltage between terminals.
Are the voltages balanced?
Yes
Check the compressor.
MUZ-FD50
Disconnect the terminal of the compres-
sor. 3 minutes after turning on the power
supply, start EMERGENCY OPERATION.
Measure the voltage between each lead
wire leading to the compressor.
U (BLK) - V (WHT)
V (WHT) - W (RED)
W (RED) - U (BLK)
Is output balanced?
Yes
Is the input voltage to the outdoor
electronic control P.C. board 370 V or
more?
Yes
Turn OFF power supply of indoor and
outdoor unit, and measure the com-
pressor winding resistance between the
compressor terminals.
Is the resistance between each terminal
normal? (Refer to 11-4.)
Yes
Reconnect the lead wire of compressor, and
turn ON power supply to indoor and outdoor
unit.
3 minutes later, starts EMERGENCY OP-
ERATION.
Does the compressor run for 10
seconds or more after it starts?
No
After the compressor is heated with a
drier, does the compressor start? 1
Yes
Compressor start failure. Activate pre-heat
control.
(Refer to 10-2. "PRE-HEAT CONTROL
SETTING")
See 11-5.
Replace the inverter P.C. board.
No
See 11-5.
•
After the outdoor fan starts running, wait for 1 minute or more before measuring the volt-
age.
•
Output voltage is 50 - 130 V. (The voltage may differ according to the tester.)
No
Replace the power board.
No
No
Replace the compressor.
Refer to <<Judgement>>.
Check the refrigerant
Yes
circuit.
Check the stop valve.
Refer to <<Judgement>>.
No
Replace the compressor.
40
40
"Check of open phase".
"Check of compressor".
<<Judgement>>
0 second
1 second
2 seconds
10 seconds
10 minutes
Heating part
Compressor starts
Abnormal
(IPM failure)
(Compressor winding short)
Abnormal
(Compressor lock out)
(Starting defect)
Abnormal
(Poor contact,)
(Outdoor P.C. board defect)
(Disconnected connector)
Abnormal
(Refrigerant circuit defect)
(Closed valve)
Normal
1
Heat the compressor with
a drier for about 20 minutes.
Do not recover refrigerant
gas while heating.
Advertisement
Table of Contents
