Carrier 619FB Service Manual page 38

5. Diagnosis for failure start up malfunction (AP1 below is control board of outdoor unit)
Main detection points:
S Is the compressor wiring correct?
S Is the compressor stop time long enough?
S Is the compressor damaged?
S Is the refrigerant charged correctly?
Malfunction diagnosis process:
If the compressor wire COMP(UVW) is
well connected and connection sequence
Energize the unit
and start it
If the stop time of compressor
is more than 3min?
Yes
is correct
Yes
Is the unit overcharged?
Yes
Charge the
refrigerant according
to service manual
Does the unit start
up normally?
No
Replace control board AP1
Is the malfunction
removed?
No
Replace the
compressor
End
Fig. 41 – Troubleshooting
If the stop time is not enough and the
No
high and low pressure of system is not
balance , please start it after 3min
Improve the connection situation
of control board AP1 and
N
No
compressor COMP, connect it
with wiring diagram
Does the unit start
up normally?
N
No
Yes
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