Carrier 40MBDAQ - Page 34

40MBDAQ: Service Manual
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34
DIAGNOSIS AND SOLUTION (CONT.)
P2 (Top temperature protection of the compressor Diagnosis and Solution)
Description: If the sampling voltage is not 5V, the LED displays a failure.
Recommended parts to prepare:
• Connection wires
• Outdoor PCB
• Overload protector
Troubleshooting
Check if the air ow system
of the indoor and outdoor units
are obstructed.
Clear up the air inlet and outlet or the heat
exchanger of indoor and outdoor units.
Yes
No
Yes
Yes
Turn o the power supply and turn
it back on 10 minutes later.
Check if the temperature of
compressor Top is more than 90°C.
No
Check if the refrigerant
system is normal.
Repair the refrigerant
system.
Replace the outdoor control PCB.
Yes
Check if all the connections, especially
the connection of OLP (Over Load
Protector) sensor is good.
Correct the connection.
No
Measure the resistance
between the two ports of
the OLP. Is it zero?
Yes
Replace the OLP.
No
Replace the outdoor control PCB.
Yes
No