Carrier 40MAHB Series Service Manual page 31

40MAHB: Service Manual
DIAGNOSIS AND SOLUTION (CONT)
Over voltage or low voltage protection (PC01)
Description: Abnormal increases or decreases in voltage are detected by checking the specified voltage detection circuit.
Recommended parts to repair:
• Power supply wires
• IPM module board
• PCB
• Reactor
Troubleshooting
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Check the power supply.
Is it in working order?
YES
Check the connections and wires.
Are they in working order?
YES
Power on and measure the
voltage between P and N.
While the unit is in the standby mode,
is the voltage between P and N around
DC 310V, 340V or 380V?
At unit start up, is it
220V~400V?
YES
Check the reactor.
Is it in working order?
YES
Replace the reactor.
NO Turn off the unit.
Ensure the proper connections
NO
or replace the wires.
NO Replace the IPM board.
NO Replace outdoor PCB.
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