Carrier 40MAHB Series - Page 33

40MAHB: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
33
DIAGNOSIS AND SOLUTION (CONT)
Top temperature protection for compressor or High temperature or High pressure protection of IPM module (PC02) (cont.)
Are the high pressure switch
and main control board wired
correctly?
Yes
Yes
No
Is the outdoor ambient
temperature higher than 122°F(50°C)?
No
Yes
No
Yes
No
No
Yes
Stop the unit.
Is the high pressure
protector broken?
Check if the outdoor unit
ventilation is good.
Ensure that the outdoor unit’s
ventiliation is functioning properly.
High pressure protection
Connect the high pressure switch
and main control board.
Method: Disconnect the plug.
Measure the high pressure protector
resistance. If the protector is normal,
the value is 0.
Does the problem still exist?
No
Replace the
high pressure protector.
Yes
No
Refer to the “Fan Speed is operating
outside of Normal Range” malfunction.
Is the outdoor fan running properly?
Is the heat exchanger dirty? Clean the heat exchanger.
Replace the outdoor main board.
Is the problem resolved?
Check whether the refrigerant
system is functioning properly.