Single Phase AC MOTOR stuck

[Christopher]

I am trying to fix a single phase ac motor but need some help. When powered on and put off load, motor humms but doesnt rotate, its sort of magnetically locked because even trying to rotate by hand it very hard to turn (motor was removed from housing and therefore I have stator and rotor exposed)

When switched off, rotor turns freely and smoothly by hand, therefore bearings are not an issue.
Motor is a capacitor run. Checked capacitor and both windings, all looks fine (see image attached). Coils ohmage measured was 15 and 40 ohms and capacitor reads 10microF OK.

Can someone please help what could be the problem? Thanks!

 

[dmxtothemax]

Clearly the start up is not working,
If their is no cetrofugal switch ? then it could be capacitor fault
Or even faulty start windings.
I would replace the capacitor first.

 

[westward10]

Have you checked that the start cap is OK and the centrifugal switch is operating correctly?

So how or what disconnects the start winding during the initial start up procedure?

It is a permanent split capacitor or single value capacitor motor there is no centrifugal switch the aux winding is permanently connected.

 

[Christopher]

Clearly the start up is not working,
If their is no cetrofugal switch ? then it could be capacitor fault
Or even faulty start windings.
I would replace the capacitor first.

Hi dmxtothemax,
Thanks for your reply. Thank you I will replace capacitor just in case. Will it be expected for rotor to lock (and unable to turn by hand) if its a start up issue?
[automerge]1589606421[/automerge]

Have you checked that the start cap is OK and the centrifugal switch is operating correctly?

So how or what disconnects the start winding during the initial start up procedure?

Hi Pete999,

Capacitor tested ok and not faulty, but will replace capacitor just in case.

 

[Pete999]

Hi dmxtothemax,
Thanks for your reply. Thank you I will replace capacitor just in case. Will it be expected for rotor to lock (and unable to turn by hand) if its a start up issue?
[automerge]1589606421[/automerge]

Hi Pete999,

Capacitor tested ok and not faulty, but will replace capacitor just in case.

Are you trying to run this motor up with only 1 end plate in place? and the rotor only fixed at 1 end of the housing? an odd question I know, but sometimes people do do some strange things.

 

[Christopher]

Are you trying to run this motor up with only 1 end plate in place? and the rotor only fixed at 1 end of the housing? an odd question I know, but sometimes people do do some strange things.

I am trying to run it fixed as it should be: with both rotor ends inserted into both bearings.

 

[Pete999]

I am trying to run it fixed as it should be: with both rotor ends inserted into both bearings.

Thanks Mate, needed to ask, seen some stupid stiff in my time, not in any way that what you have done is stupid,

 

[Nilesh]

I am trying to fix a single phase ac motor but need some help. When powered on and put off load, motor humms but doesnt rotate, its sort of magnetically locked because even trying to rotate by hand it very hard to turn (motor was removed from housing and therefore I have stator and rotor exposed)

When switched off, rotor turns freely and smoothly by hand, therefore bearings are not an issue.
Motor is a capacitor run. Checked capacitor and both windings, all looks fine (see image attached). Coils ohmage measured was 15 and 40 ohms and capacitor reads 10microF OK.

Can someone please help what could be the problem? Thanks!

Hi
Did you solve the issue, how
I have the same issue in motor

 

[Petej999]

I am trying to fix a single phase ac motor but need some help. When powered on and put off load, motor humms but doesnt rotate, its sort of magnetically locked because even trying to rotate by hand it very hard to turn (motor was removed from housing and therefore I have stator and rotor exposed)

When switched off, rotor turns freely and smoothly by hand, therefore bearings are not an issue.
Motor is a capacitor run. Checked capacitor and both windings, all looks fine (see image attached). Coils ohmage measured was 15 and 40 ohms and capacitor reads 10microF OK.

Can someone please help what could be the problem? Thanks!

Centrifugal switch gone U/S