How to Test Electrical Motors

Normally, an alarm is triggered tripping the electrical motor. To start with the diagnosis, best to first test the supply lines coming to the El motor as most suspect the secondary element "meaning the unit supplied" is al fault. It reduces valuable time to go changing an El motor, which of course is the most easiest way to think that. But, imagine if the problem is not eradicated and now what. It is mostly loose supply cable connections in the panel especially in newbuild not tightened properly well or when equipment's are in operations cause vibrations making electrical connections loose that could result in a fault.

Do you still think, you want to replace the El motor or disassemble the El motor?

Once the supply lines are cleared by knowing there is no issues there, it would be wise to check the El motor. This can be done by disconnecting the start or delta connection, isolating the 6 cables that come from inside the El motor into the connection box. Here, you can check the resistance of each of the three windings on the stator. Thereafter, an insulation test be conducted between windings and potential earth. If, any of the test prove incorrect, the particular area can be identified as fault. In some cases, there could be a new problem, then perhaps the rotor core comes in contact with the stator core core due either causes can be a roller bearing failure or some broken part (that are good conductor to electricity) get stuck between the rotor & stator core.

To avoid above issues, it is always good to keep a good healthy PMS on machines that can always be reliable in operations.