Carrier 38MGRBQ18B-3 - DIAGNOSIS AND SOLUTION (CONT); High Pressure Protection Diagnosis

38MGRBQ: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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DIAGNOSIS AND SOLUTION (CONT)
P1/PC 30 (High pressure protection) diagnosis and solution
Troubleshooting
ERROR CODE
P1/PC 30
MALFUNCTION DECISION
CONDITIONS
If the sampling voltage is not 5V, the LED displays the failure.
SUPPOSED CAUSES
Wiring mistake
Faulty over load protector
System block
Faulty Outdoor PCB
Is the wiring between
the high pressure switch and
the main control board is
connected well
M
e
th
od
:
.
,
i
f
,
Method: Disconnect the plug.
Measure the resistance of
the
high pressure protector, if
the protector is normal the
value is 0,
Yes
Yes
Connect it well No
Replace high pressure protector
No
Is the high
pressure protector
broken?
Check whether the outdoor
ambient temperature is
higher than 50ć
No
Stop the unit Yes
Check if the outdoor unit
ventilation is good
Yes
Check whether the heat
exchanger is dirty
No
Clean the heat exchanger Yes
Check whether the refrigerant
system is ok
Replace outdoor main
board
No
High pressure protection
Check if the outdoor fan runs
properly
Refer to the Fan Speed is Out of
Control solution. Determine
the cause and solve.
No
Yes
NO
Ensure the outdoor unit
is well ventilated