YES
YES
YES
Correct it.
NO
NO
NO
YES
NO
YES
NO
Is the low pressure sensor
correctly connected?
Check the value on the low
pressure sensor, via indoor
unit, in: (1) stationary
compressor, (2) compressor
operation.
Is the value around 0 MPa, without
significant change, both in states
(1) and (2)?
Check the insulation resistance on
the low pressure sensor.
Is the resistance greater than
100 Ω at DC 500 V?
Connect a pressure gauge to the
low pressure pipe and measure in
state (1). Compare with the value
shown on the indoor unit.
Replace the low pressure
sensor.
Is the difference less than 0.2 MPa?
Advance to checking the refrigerant
circuit on the next page.
Connect a new low pressure
sensor to the control PCB and
position it open in the atmosphere.
Is the pressure 0 MPa in the indoor
unit?
Replace the control PCB.
Replace the low pressure
sensor.
To next page