Mechanical or Electrical?

How often do you have the situation where the Fitter says it’s definitely an electrical fault and the Electrician is convinced it’s mechanical?

I can’t recall how often I had this during my career and here is a tip on how to find out

The motor starts and runs a bit then trips out on the thermal overload. What I would do is to do a complete motor test and when testing the continuity of the windings, I generally accept that the motor is fine if the reading of all windings is within 10% of each other.

The next step is to disconnect the motor from the mechanical equipment, gearbox or pulley etc., and start it again. Use your clamp meter and as a rule of thumb, I will be expecting the motor to draw around a third of the maximum amperage on the nameplate. If the reading is close to this, the motor is good and you will find the fault on the mechanical side.

We will discuss the full motor test on the next post. It is very important and you will note that I tend to check for mechanical damage as well.

Until then, remember to always put safety first.