Carrier 40MB C Series Service Manual page 29

High temperature protection of compressor top diagnosis and solution (P2)
Error Code
Malfunction decision conditions
Supposed causes
Check the air flow system
of indoor and outdoor units
No
Power off, then restart the unit
3 minutes later
Yes
Check if the temperature
of compressor
Yes
Check refrigerant system
P2
If the sampling voltage is not 5V, the LED displays the failure.
S
Power supply problems
S
System leakage or block
S
PCB faulty
Clear up the air inlet and outlet or the heat
Yes
exchanger of indoor and outdoor units.
Check the overload
No
Measure the resistance
between the two ports of
the OLP. Is it zero?
Yes Replace the outdoor control PCB.
Fig. 39 – Troubleshooting
No Correct the connection.
protector
Yes
No Replace the OLP.
Yes
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