Jogging of a DC motor

[rajendrad]

I am facing problem with a DC motor & drive. Drive used is of ABB. When I Switch on the drive , the motor starts jogging. I checked speed ref from PLC and also the same has been removed but still it joggs. I changed firing board and mother board of the drive and also replaced the thyristors still problem is there. Could you all please help me to solve the problem

Thanks

 

[nif]

Hello!
Have you checked if you have any direction commands on?
If you have and you have parametrized a minimum speed then it will start.
Have you checked the wireing?
Check the field(magnetizing) cabels if they are connected or if there any electizity going all the time then it will rotate.

 

[hesham]

hi
Do you mean by jogging that the motor is start to rotate and the stop and then rotate and so on Or the motor is running at a low speed continuosly?
Most propably you are controling you drive from the control terminal please try to change the operating mode to the keypad and let us know the result.
Also for the time being you must have a run command and a speed referance(Jogging speed) applied to your drive in order to run .Please check thoe two signals
Best Luck

 

[panic mode]

I agree with hesham. Try to better explain problem.
Is the motor drifting all the time or
it still moves but at low speed when speed is set to zero?
Not all drives have true 0-100% speed control so it is not
that unusual that motor would move when you issue run command
even if speed reference is set to zero. What control signals
you have? How about "Drive Enable"...?

 

[DickDV]

And, if you please, tell us the drive model number.

 

[rajendrad]

Dear friends,

I had written this thread when I got a complain from customer and tried to explain what he talked to me. When actually I was gone to site I was able to solve this problem. This was a shear drive and when I checked speed referance ckt, found when Accelaration On command from PLC comes to drive, Normal speed referance and torque referance is getting added during that time. This DI ( accelaration On) from PLC was coming contneously high that's why eventhough there is no speed ref signal from PLC but only torque ref signal was going out at all the time hence motor was jogging. After changing relay card everything was working OK.

Hope you will understand what I am talking about. Thanks to all for your help.

Rajendra