R
Roy Matson
Adil,
If you just measure the winding resistance with an Ohmmeter because the windings are quite low in resistance it would be hard to detect a shorted turn. If you pass an AC current though the winding a shorted turn will show up as a high current. Because you don't want the motor to start or burn out use a lower voltage with Ammeter in series. As an example of what I mean take a normal low voltage transformer, measure the primary resistance with your Ohmmeter, now short out the secondary - no difference in primary Ohms!
But you know without even testing it that if you connect the transformer to the AC supply and short out the secondary you will get a huge difference in primary current. So what I am trying to explain is how to measure the AC resistance (reactance).
The amperage you get is not important just that each winding should be the same indicating that there are no shorted turns. I don't say this is infallible, it's possible that the winding could short under running and not at rest but if you get a high current on one winding it points to a problem for sure.
Is it possible that one winding is reversed, i.e. swapped end for end?
If you just measure the winding resistance with an Ohmmeter because the windings are quite low in resistance it would be hard to detect a shorted turn. If you pass an AC current though the winding a shorted turn will show up as a high current. Because you don't want the motor to start or burn out use a lower voltage with Ammeter in series. As an example of what I mean take a normal low voltage transformer, measure the primary resistance with your Ohmmeter, now short out the secondary - no difference in primary Ohms!
But you know without even testing it that if you connect the transformer to the AC supply and short out the secondary you will get a huge difference in primary current. So what I am trying to explain is how to measure the AC resistance (reactance).
The amperage you get is not important just that each winding should be the same indicating that there are no shorted turns. I don't say this is infallible, it's possible that the winding could short under running and not at rest but if you get a high current on one winding it points to a problem for sure.
Is it possible that one winding is reversed, i.e. swapped end for end?