Carrier 38MARBQ12AA1 Service Manual page 50

DIAGNOSIS AND SOLUTION (CONT)
Top temperature protection for compressor or High temperature or High pressure protection of IPM
module (PC02)
Description: For some models with overload protection, if the sampling voltage is not 5V, the LED displays the failure. If the IPM module
temperature is higher than a certain value, the LED displays the failure code. For some models with a high pressure switch, the outdoor pressure
switch cuts off the system when the pressure is higher than 4.4 MPa and the LED displays the failure code
Recommended parts to repair:
• Connection wires
• Outdoor PCB
• IPM module board
• High pressure protector
• System blockages
Troubleshooting
Check if the air flow system
of the indoor and outdoor units
are obstructed.
No
Turn off the power supply.
Wait 10 minutes and turn back on.
Yes
Check if the compressor top
temperature is more than 90°C?
Yes
Check if the refrigerant
system is normal.
Yes
Replace the outdoor control PCB.
NOTE: For certain models, the outdoor PCB can not be removed separately. In this case, the outdoor electric control box should be replaced as
a whole.
50
Clear up the air inlet and outlet or the indoor
Yes
Check if all the connections, especially
the OLP (Over Load Protector) connection
No
Measure the resistance
between the two O L P ports.
No
Repair the refrigerant
system
Check the fastening screws on the
PCB and IPM radiator.
Are they
fixed tightly?
NO
Tighten the screws and apply
silicon grease.
Specifications subject to change without notice.
and outdoor heat exchangers.
sensor, is good.
Yes
No
Is it zero?
Replace the outdoor control PCB.
Yes
Replace the outdoor
YES
control PCB.
.
Correct the connection.
No
Replace the OLP.
SG-38MARB-01