Problems
Inspection
points
Indoor unit
Indoor unit does not operate.
Breaker
Refrigerant gas pressure
(9)
(10)
Operation lamp blinking.
Operation lamp does not illuminate.
Indoor fan dose not turn.
Outdoor unit does not operate.
Outdoor fan dose not turn.
4-way valve does not operate.
The compressor (only) does not
operate.
The compressor stops on occasion.
The compressor speed does not
increase.
The outdoor air temperature is high,
however defrost operation occurs.
Defrost operation does not occur.
The electric expansion valve does
not operate.
Does not cool or cooling
performance is inadequate.
Does not heat or heating
performance is inadequate.
Outdoor unit
Others
No. of
Inspection
Points for
Each part
Others
8-4-2. Inspection Points for Each Part
(1) Outdoor control circuit board
Refer to "8-3-1. Checking the outdoor unit".
(2) Fuse
Check it visually or the continuity with a tester.
(3) Compressor
Check for an open circuit in the compressor coil winding.
(4) Compressor protective sensor (compressor discharge temperature thermistor)
Check that the senseor is securely contained in the thermostart holder.
(5) 4-way valve
Short-circuit the T-RUN terminal to the COM terminal of TEST/T-RUN terminals. Perfrom a test run of the unit
alone, and check whether the 4-way valve inside the outdoor unit produces a click sound.
(6) Coil thermistor
Check that the sensor is securely contained in the thermostat holder.
Do not remove or insert the outdoor control circuit board connector when power is being supplied to it.
(The controller will be damaged.)
NOTE
57
