Mitsubishi Electric SUZ-KA09NA2 Service Manual page 26

N Check the defrost heater
SUZ-KA09/12/15NAH2
Check the following points before checking electric continuity.
1. Does the resistance of ambient temperature thermistor have the characteristics? Refer to 10-6.1.
2. Is the resistance of defrost heater normal? Refer to 10-4.
3. Is the heater protector closed?
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
32°F (0°C) or below, and let the defrost thermistor continue to read 30°F (-1°C) or below.
Is there 208/230 VAC between CN722
the inverter P.C. board? Refer to 10-6.1.
Replace the inverter P.C. board.
O Check of outdoor refrigerant circuit
Has the operation stopped
during pump down?
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. *
WARNING:
When opening or closing the valve
below freezing temperatures,
refrigerant may spurt out from the gap
between the valve stem and the valve
body, resulting in injuries.
* CAUTION : Do not start the operation again to prevent hazards.
OCH699A
NOTE: In case both thermistors are more than the above temperature, cool them with cold
water etc...
and on
No
Was the operation started with
the stop valve closed, and was
No
it opened during operation?
The refrigerant gas amount may be
60% or less than the normal amount.
Identify where the gas is leaking from,
and fix the leak.
Not the problem of the inverter P.C. board.
Yes
Yes
No
26
The unit occasionally stops when the
stop valve is opened or closed during
operation. Open the stop valve and
start the cooling operation again.