Mitsubishi Electric MUZ-FH35VEHZ Service Manual page 48

N Check of defrost heater
Check the following points before checking electric continuity.
1. Does the resistance of ambient temperature thermistor have the characteristics? Refer to 11-6.1.
2. Is the resistance of defrost heater normal? Refer to 11-4.
3. Does the heater protector remain conducted (not open)?
4. Are both ambient temperature thermistor and circuit of defrost heater securely connected to connectors?
In HEAT mode, for more than 5 minutes, let the ambient temperature thermistor continue to read 0°C or
below, and let the defrost thermistor continue to read -1°C or below.
Is there 230 V AC between CN722
(MUZ-FH25/35)/CN601
the inverter P.C. board? Refer to 11-6.1.
Replace the inverter P.C. board.
O Check of outdoor refrigerant circuit
Has the operation stopped during pump down?
No
Was the operation started with the stop valve
closed, and was it opened during operation?
No
The refrigerant gas amount may be 60% or less than
the normal amount. Identify where the gas is leaking
from, and fix the leak.
OBH625G
NOTE: In case both thermistors are more than the above temperature, cool them with cold
water etc...
and
and (MUZ-FH50) on
No
Yes
Yes
Not the problem of the inverter P.C. board.
Yes
The operation has stopped to prevent the diesel explosion
caused by air trapped in the refrigerant circuit. Close the stop
valve, and disconnect the power plug or turn the breaker OFF.
CAUTION:
Do not start the operation again to prevent hazards.
The unit occasionally stops when the stop valve is opened or
closed during operation. Open the stop valve and start the
cooling operation again.
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