Bardac DC Drives

Just a quick (but long) question:

Has anyone experienced issuse with the Bardac 3600XRi/32 model? I have a very serious issue with a motor reversing direction when it shouldn't be. The control is based on Beckhoff I/O, and is being controlled by a proprietary motion control system. All other axes in the system are working perfectly.

Prior to shipping out the job (which consists of approx 30 drive units), I had a strange episode with one of the drives in our shop. The quench circuit built into the drive didn't work properly (FS did NOT result in a fast stop), and when I sent it back to the factory, it was determined by Bardac that the drive had no problems. I had our local vendor's tech guy verify the failure of the quench circuit in our shop, so I had a second set of eyes confirming the problem. This drive has since been returned to me (with a BRAND NEW drive), although Bardac denied problems.

Now, I have (possibly) a second drive acting erratically. We plan on changing out the Beckhoff front end first.

But......

I am a bit worried that the drive(s) may be failing, and really don't want to keep replacing them. Especially 30 of them.

Any insight?

Thanks,
Bryan

Bryan, you simply haven't given us anywhere's near the specifics necessary to help you. For example, if the motor is reversing when it isn't supposed to, is the drive also going into reverse or is this a motor issue? If the motor is reversing, is the armature reversing polarity or is it the field that is reversing?

The list goes on! Give us something more to work with.

DickDV said:

Bryan, you simply haven't given us anywhere's near the specifics necessary to help you. For example, if the motor is reversing when it isn't supposed to, is the drive also going into reverse or is this a motor issue? If the motor is reversing, is the armature reversing polarity or is it the field that is reversing?

The list goes on! Give us something more to work with.

Click to expand...

Dick
Are you saying that a DC motor can reverse all by itself without reversing any of the controls?

OR are you saying the load is reversing the motor?

Assuming a shunt motor (for simplicity sake ??)
AND I never change the polarity of the supply conductors to the shunt field
AND I never change polarity of the conductors to the armature
The motor can change direction?
I have never heard of this (which means nothing of course)
Under what conditions can this happen?

Dan Bentler

Dan, unless the motor is being overhauled to the extent that it is forced to turn in reverse, I would only expect the motor to reverse if either the field or the armature polarity is reversed.

That's really my question to the original poster. When the motor reverses, what, if any, connections are reversing polarity?

Thanks Dick
I was trying to figure out how to get a DC motor to reverse itself all by itself. Based on your input I will stop trying.

Dan