Is an AC line Filter necessary for a servo drive. 1

[moosetracks555]

When is a AC line filter needed or not needed? The motor is a 5 Amp 480 V servo motor on an 11Amp servo drive. There will be about 50 feet of cable between the drive an motor. The servo will be making about 1 or 2 trapezoidal moves per min. We have lots of servos, and non of them have line filters on them, or if they do they are part of the drive hardware. This one is an Allen Bradley, and our distributor recommended them as a part of a complete package, but I wanted to know what they are for, and if we need them.

 

[itsmoked]

Your question is vague. Is this a filter on the input of the drive or the output on the way to the motor.

In all cases filters reduce efficiency and cost money.

A supplier will always suggest them as they can head off operational issues.

If they plant isn't using them and has no issues I probably wouldn't add one. I might note that they could be a possible requirement, and they cost about x$, for the user. So if you need one it isn't an out-of-the-blue surprise to the user's bottom line.

If you mean on the input then this is to prevent/reduce EMI from heading back out into the power wiring and causing problems with other plant equipment.

If you are talking on the line to the motor then they can extend the life of the motor by carving off the sharp electrical spikes that ultimately challenge the winding insulation. If one is foolish and runs the output lines near other plant wiring, an output filter can help with that too.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[moosetracks555]

itsmoked,

Thanks for your comments. It is a before the drive device. Here is the info from AB...
2090-UXLF-HV323 1 AC LINE FILTER,ULTRA,23 AMPS, 460V, 3 PHASE. $329.00

The device is suppose to prevent electrical noise from the drive entering the rest of the system.

 

[itsmoked]

Yeah, that's a cover their butts suggestion probably.
Like I say - it might be needed. If some sensor starts acting up, or the other drives start hunting, or the cows all stop giving milk, it may still be needed.

BTW Thanks for coming back on that.

Keith Cress
kcress -

http://www.flaminsystems.com