ABB DCS 500 speed control problem.

[raghand]

We are currently suffering a reoccuring problem where a section of our machine runs backwards when requested to jog or run. This problem is reoccuring but happens once and then machine will run without fault for long periods of time.
Drive controlling section is a ABB DCS 500
We have set up test equipement to monitor speed input reference and speed feedback. We captured on the latest results that the speed input reference was positive in amplitude but the feedback was negative.
This to me suggests that the fault or problem lies within the DCS drive.
Could this be a incorrect parameter setting or an actual fault with the control card?

 

[niallnz]

What sort of speed feedback are you using? DC Tacho generator or AC Tacho or encoder?.

If you are not operating the motor at greater than rated speed (ie not into field weakening) you could set the DCS500 to use teh back EMF as the speed feedback and see if it behaves differently.

Also is the DCS500 configured so that direction is set by the analog speed reference, forward and reverse can be controlled by digital inputs.

Cheers

 

[Thedroid]

We have 2 of the same drives each running 2 kiln drive motors. I'll ask if anyone has ever seen something like this. As far as i've seen, we've never had a problem with the drives. we use a dc tacho on each motor.

 

[raghand]

Feedback is generated from an increamental encoder, 1024 p/rev bidirectional.
The drive is part of a paper converting line and is the slave in a master/slave control set up. So speed control is via analogue input signal -10v - 0v - 10v.
The fault again has gone into hiding and has not appeared since last I posted. Its most frustrating as we know its going to reappear, and we'll get the usual remarks from production "thought you fixed it last time?".
If only they knew what an intermitant fault takes to find.

 

[Skogsgurra]

Some drives can be set up to use either the two quadrature traces (A and B) of the encoder or just one single trace (A or B). There might be a problem there. Check the configuration data for the encoder.

Gunnar Englund

http://www.gke.org

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