motor rotation proble

[A.N.O]

hi
I have problem in motor,its rotation is slower than before.
Its starting method is star delta and it is slow in both of them
can any one help me???
I want to know the problem is in power circuit or in the motor itself ?
thanks advance

 

[burt007]

How are you driving them? Hbridge? by pulse or what? Check the voltage across the motor, remove them and test them outside to see that they are ok. Are the dc motors or ac? brush or brushless? or stepper? Give some more information as to the type of motors the circuitry around them etc.

hi
I have problem in motor,its rotation is slower than before.
Its starting method is star delta and it is slow in both of them
can any one help me???
I want to know the problem is in power circuit or in the motor itself ?
thanks advance

 

[A.N.O]

the motor is AC ,3-phase motor
I check the voltage between its pole it was 380

 

[WimRFP]

You mentioned star/delta starting so you don't use a VFD. The RPM is determined by the mains frequency, number of poles and the load (assuming an induction motor).

If you did not change anything there must be increased load or a malfunction in the motor. When RPM reduces significantly, the motor current would increase (more then factor 2), resulting in smoke, blowing a fuse, damage, etc

Did you actually measure the motor speed (at the motor shaft) and determined the slip?