Carrier 40MHHQ18-3 - High Temperature Protection of Compressor Top (P2)

SG-38MHRC-01 Specifications subject to change without notice. 45
DIAGNOSIS AND SOLUTION (CONT)
High temperature protection of compressor top diagnosis and solution (P2)
Description: If the sampling voltage is not 5V, the LED displays the failure.
Possible causes:
• Power supply problems
• System leak or block
• Faulty PCB
Troubleshooting:
Yes
Tighten the screws and apply
silicon grease.
Replace the outdoor control PCB.
No
Ensure the fastening screws
on the PCB and IPM radiator
are tight.
For other models,
Are the indoor and outdoor
units air ow systems
obstructed.
Clear the air inlet and outlet or the indoor
and the outdoor unit’s heat exchangers.
Turn o the power supply.
Wait ten minutes then turn back on.
Is the compressor top
temperaure is higer than 90°C?
Are the connections, especially
the OLP connection (Over Load
Protector) sensor good?
Correct the connections.
Is the refrigerant system normal?
Measure the resistance
between the OLP’s two ports.
Is it zero?
Replace the OLP.
Repair the
refrigerant system.