
40MBAB: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
26
DIAGNOSIS AND SOLUTION (CONT.)
PC 01 - Over voltage or too low voltage protection / PC 10 - Outdoor unit low AC voltage protection / PC
11 - Outdoor unit main control board DC bus high voltage protection / PC 12 (Outdoor unit main control
board DC bus high voltage protection / 341 MCE error 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 wires
• IPM module board
• PCB
• Reactor
Troubleshooting and Repair:
NOTE: For certain models, the outdoor PCB could not be removed separately. In this case, the outdoor electric control box
should be replaced as a whole.
Check the power supply.
Is it in working order?
Turn off the unit.
NO
Check the connections and wires .
YES
Are they in working order?
NO
Power on and measure the
voltage between P and N.
YES
While the unit is in
STANDBY mode, is the
voltage between P and N and around
DC 310V, 340V or 380V?
When the unit is started,
is it in 220V~400V?
Replace the IPM board.
NO
Check the reactor.
YES
Is it in working order?
Replace outdoor PCB.
NO
Replace the reactor.
YES
Ensure proper connections or
replace the wires.