Servo motor power with signal wiring

[skabike]

I have a machine that is going to be installed into an isolator type fume hood so I need to keep the power and I/O to a minimum. There four servo motors using 48vdc, a handfull of solenoids(24vdc), limit/home switches, and some rs232 comms. The power supplies are all separate to avoid noise issues. Can I get away with running all power wiring in one multiconductor cable w/ twisted pairs and another for signal/comms?

 

[Skogsgurra]

That depends a lot on what kind of servos you have. PWM servos would probably cause some concern even though they seem to have an isolated supply. Capacitive coupling usually is enough for them feed EMI back into the feeding cable.

Considering that they are isolated (and perhaps filtered?) I would try with the configuration you mention. But I would use separate screens for all of the twisted pairs. And probably also for the power cables.

If the servos are linear (non-switching), which is highly unlikely, you do not have to be concerned about EMI at all.

There may be some code issues as well. I do not know about your country, but some countries have rules about power and signals in the same cable. Check that out with a sparky.

 

[skabike]

Thank you for the advice. Sounds like the only obstacle might be the country - going to ship this beast to our Ireland facility. Sure glad I found this forum.