In this month's technician's tip, we go over alarm codes on the Magnetek Crane Inverter Drive P3 Series 2. Rob will walk us through common alarm codes and failures on this drive, their cause, and tips on how to resolve them.

Under voltage or overvoltage (UV or OV) refer to issues with the incoming power. Check wiring for the input terminals and verify voltage is in the proper range. We recommend using a true RMS meter when checking line voltages. If an overvoltage alarm occurs while braking, the problem may lie with the regeneration circuitry in the drive or with any external braking resistor unit.

Overheat, or ‘OH’, alarms can be caused by cooling fans failing. Make sure the cooling fans are working properly and verify that there is no dirt or debris on the cooling fins of the drive.

Overcurrent alarms (OC) tend to point to issues with the motor, motor cable or output circuitry in the drive. It is a good idea to have the motor checked to see if that is causing overload or over-current issues. Use a megger to check insulation for low resistance or shorts to ground.

Problems with the incoming power are often shown as PF, phase loss. Typically, this occurs when one phase drops out or fails. LF shows an output phase alarm and points to a problem with the output connections or cables. Check the motor for any shorts and double check the output terminals for loose connections.

For more detailed troubleshooting or inquiry about repair, please contact us today at 800-551-4420.