Real-World Noise Problems

Good afternoon,

Last week I had an issue with noise affecting some Kinetix 6500. A new analog drive was installed about 5 feet below these drives, but the gains on the drive were not set properly. This caused interference on the A.B. Kinetix drives and caused them to fault out. Lowering the gains on the analog drives solved the problem.

I wanted to hear other examples from people here in this community on their own noise-related issues, how they troubleshooted, etc. This noise issue seems very difficult to pinpoint and I would like to here other people's stories on how they prevent noise from causing too much problems in their panels.

Hopefully these examples will help me improve my own troubleshooting and design skills in the future.

Thanks ,

Check for proper grounding. Avoid wires that are too long, or coiled up excessively. Run signal wires separately from power wires. Ask the manufacturer, in your case Allen Bradley since they make the Kinetix 6500, for suggestions on how to reduce noise.

Any drives, servo, vfd, whatever, I put line reactors on their power inputs. When I'm commissioning a panel that doesn't have them and exhibits similar problems to what you're describing I start with installing line reactors. And in each case problem disappeared.

Check this out. Lots of good info plus links to other resources and information.

http://literature.rockwellautomation.com/idc/groups/literature/documents/rm/gmc-rm001_-en-p.pdf

This may be helpful also.

http://literature.rockwellautomation.com/idc/groups/literature/documents/at/motion-at004_-en-p.pdf

We commissioned a Kinetix 6500 driving an old Anorad linear motor. All was well until we coupled the motor to its load at which point we started getting feedback faults. We ended up running the shielded motor cable through a separate grounded conduit and experimented with different grounding methods (ground at the motor, at the drive, both, etc.) until we found scheme that worked. No noise issues in a couple of years of operation.

Use an oversized braided ground strap. You need more Ground.