Carrier 40MPHA Service Manual page 34

P1 (Over voltage or too low voltage protection diagnosis and solution)
Description: Abnormal increases or decreases in voltage are detected by checking the specified voltage detection circuit.
Recommended parts to prepare:
• Power supply issues
• System leakage or blockage
• Faulty PCB
Troubleshooting and Repair:
Check the power supply.
Is it in working order?
Check the connections and wires.
Are they in working order?
Power on and measure the
voltage between P and N.
While the unit is in standby,
is the voltage between P and N around
DC 310V, 340V or 380V? On unit start up
is the unit in the 220V~400 range?
Is it in working order?
Replace the reactor.
34
YES
YES
YES
Check the reactor.
YES
Specifications subject to change without notice.
NO
Turn off the unit.
Ensure proper connections or
NO
replace the wires.
NO Replace the IPM board.
NO Replace outdoor PCB.
40MPHA-03SM