Electric Motor Diagnosis
Electric motor problems are often misdiagnosed, resulting in unnecessary replacement. Malfunctioning motors can often be repaired, so it is important to accurately identify and remedy the problem to save time, money, and down time whenever possible, especially for critical systems. If a motor is not repairable, the cause of failure should be determined to prevent premature failure of the replacement.
Most electrical issues involve problems with power to the motor. This can include starter or contactor issues, or failure of the coil or contacts. If a VFD is used, fault codes will often indicate issues such as over-amperage to assist in diagnosis. An over-amping motor should be checked to see that it is not seized or rubbing, and that bearings are lubricated and in good condition. Verify that the motor can receive the proper voltage and that amperage is within range of the nameplate requirements. Megger testing may be required to check for a short to ground or between phases.
Bad or improperly-lubricated bearings can seize a motor and bend a shaft due to overheating. Excessive dust or dirt accumulation is another common cause of overheating. Vibration, which can be due to a number of issues, can damage or destroy a motor and should be kept in check. Larger motors should be checked on an annual basis for vibration. Remote vibration sensors bearing wear indicators and are recommended where possible.
As with all equipment, regular preventive maintenance is required to keep motors running properly. Most manufacturers provide online operating, maintenance, and troubleshooting information. If you have further questions or are experiencing motor issues, please contact our Service Group at 609-921-1394.