Century COMFORT-AIRE VMH-SG Series Service Manual page 105

Service Manual - VMHxxSG
TS10-S: 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 wires
• IPM module board
• PCB
• Reactor
Troubleshooting and repair:
is the voltage between P and N is around
DC 310V, 340V or 380V? When start up
Note: For certain models, 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?
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 standby,
the unit, is it in 220V~400V?
YES
Check the reactor.
Is it in working order?
YES
Replace the reactor.
 Troubleshooting
Troubleshooting
NO Turn off the unit.
Ensure proper connections or
NO
replace the wires.
NO Replace the IPM board.
NO Replace outdoor PCB.
