Carrier 40MAHB Series Service Manual page 33

40MAHB: Service Manual
DIAGNOSIS AND SOLUTION (CONT)
Top temperature protection for compressor or High temperature or High pressure protection of IPM module (PC02) (cont.)
Measure the high pressure protector
resistance. If the protector is normal,
temperature higher than 122°F(50°C)?
Is the outdoor fan running properly?
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
High pressure protection
Are the high pressure switch
and main control board wired
correctly?
Yes
Is the high pressure
protector broken?
Method: Disconnect the plug.
the value is 0.
Does the problem still exist?
Yes
Is the outdoor ambient
No
Check if the outdoor unit
ventilation is good.
Yes
Yes
Is the heat exchanger dirty?
No
Replace the outdoor main board.
Is the problem resolved?
No
Check whether the refrigerant
system is functioning properly.
Connect the high pressure switch
No
and main control board.
Replace the
No
high pressure protector.
Yes Stop the unit.
Ensure that the outdoor unit's
No
ventiliation is functioning properly.
Refer to the "Fan Speed is operating
No
outside of Normal Range" malfunction.
Yes
Clean the heat exchanger.
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