SiBE12-908 TroubleshootingService Diagnosis 1562.32 Over Voltage Protection / Low Voltage ProtectionRemoteController DisplayU2Method ofMalfunctionDetectionDetect an abnormal increase or drop of voltage by the over voltage detection circuit or DCvoltage detection circuit.MalfunctionDecisionConditions When an over voltage signal is sent to the microcomputer from the over voltage detectioncircuit, or the voltage detected by DC voltage detection circuit is less than 150 V and thatvoltage continues for about 0.1 second. The unit shuts down if the fault conditions occurs repeatedly. Fault counter is reset when the unit continuously runs for 11 minutes without fault.SupposedCauses Abnormal supply voltage, momentary power failure Defective over voltage detector or defective DC voltage detection circuit Failure in PAM controlled parts Short circuit inside the fan motor winding.Troubleshooting(R9451)CautionBe sure to turn off power switch before connect or disconnect connector,or parts damage may be occurred.Check the supply voltage.Supply voltage asspecified?YESNO Correct the power supply.Rotate fan by hand.Does fan rotatesmoothly?YESNOTurn on the poweragain. Systemrestarted?Repeat acouple of times.NOYES(Precaution before turning on the power again)Make sure the power has been off forat least 30 seconds.Disturbance factors∗ Noise ∗ Power supply distortionReplace fan motor andoutdoor unit PCB.Check for such factors for along term.∗ Try to get restarted acouple of times.Replace the outdoor unitPCB.
