Carrier 538FEQ009RBGA, Service Manual

Page: 39 / 94

39
6. Diagnosis for compressor synchronism (AP1 below is control board of the outdoor unit)
Main detection points:
S Is the system pressure high?
S Is the voltage too low?
Malfunction diagnosis process:
If the compressor wire COMP(UVW) is well
connected, the connection sequence
forwards to clockwise direction?
Check if the fan
terminal OFAN is
connected well
Replace
compressor
If the outdoor fan works
normally?
If the stop time of
compressor is more than
3min
Synchronism after
energize the unit
and start it
Connect
wire well
Synchronism
occurred during
operation
Replace
control board
AP1
If the radiating of unit is
well?
Remove
malfunction?
Improve the radiating
of unit (clean heat
exchanger and
increase ventilation)
Replace fan
capacitor C1
Replace
outdoor fan
Yes
No
No
No
Yes
Yes
No
Replace
control board
AP1
Remove
malfunction?
Replace
compressor
Yes
No
No
Yes
If the input voltage of unit
is normal?
Start to run until the
power resume normal
voltage
N
If the refrigerant is too
much?
Charge the
refrigerant with
service manual Yes
Yes
No
Yes
End
End
No
Fig. 42 – Troubleshooting