Centroid Community CNC Support Forum

There is a reason to use shielded cable and it only does its job if ONE end is grouned.

Gary Campbell wrote: ↑Fri Mar 29, 2019 3:54 pm Chaz..
The US 18AWG size requirement converts to .75mm dia and .196mm^2, so you are undersize, which is known to cause issues

Ok, didnt think it would be as thick as that. Ill use something larger tomorrow and see. Ive used similar wire before on my other setups, no issue but ill test.

Thanks

ghack wrote: ↑Fri Mar 29, 2019 4:41 pm There is a reason to use shielded cable and it only does its job if ONE end is grouned.

Thanks, tried that, didnt make a difference.

On a VFD, it's ground needs to be carried through to the motor and the VFD grounded at the service entry point shielded VFD cable from motor to VFD is preferred

martyscncgarage wrote: ↑Fri Mar 29, 2019 5:34 pm On a VFD, it's ground needs to be carried through to the motor and the VFD grounded at the service entry point shielded VFD cable from motor to VFD is preferred

Thanks, I am using a shielded cable from VFD to motor. Its not grounded (from memory), will check tomorrow. Which side should I ground?

Chaz wrote: ↑Fri Mar 29, 2019 6:12 pm

martyscncgarage wrote: ↑Fri Mar 29, 2019 5:34 pm On a VFD, it's ground needs to be carried through to the motor and the VFD grounded at the service entry point shielded VFD cable from motor to VFD is preferred

Thanks, I am using a shielded cable from VFD to motor. Its not grounded (from memory), will check tomorrow. Which side should I ground?

You just opened up a debate with that question be prepared if you're talking about the drain wire. If you're talking about the ground wire then it gets grounded at both ends. I'm not going to comment on the drain wire though.

no worries marty i wont make any more comments on this board good day

ghack wrote: ↑Fri Mar 29, 2019 8:37 pm no worries marty i wont make any more comments on this board good day

?
I was just sharing a link. It's up to the user as to what works best for them.

I did a video that demonstrated what happened to me when one end of the cable carrying the analog signal to the VFD. It was erratic.

Marty

A few points.

Earth, done, everywhere needed.

'Drain' which I assume you mean the shield around either the VFD cable from VFD to Motor, not connected to anything.

For the signal chain, the 'drain', shielding around the 0-10V to Earth Ive tried and whilst it changes the behaviour, it remains inconsistent.

My VFD is also outside of the control box, side of the Bridgeport to keep it as clean / noise free as possible. Ill try a HY drive with the same setup and see if the issue goes away.