static causing communication problems...again

[Ken Sully]

Just a final thought. How old is your DC? Could you have a motor failing causing electrical noise in the ground leg? Seems odd the only time you have trouble is when its turned on.

[bking1836]

Just a final thought. How old is your DC? Could you have a motor failing causing electrical noise in the ground leg? Seems odd the only time you have trouble is when its turned on.

The DC is an Oneida Gorilla Pro that’s less than one year old. Seems to work perfectly.

[Burkhardt]

Get somebody with a battery operated (to avoid just another ground issue) oscilloscope to probe the various sections of your wiring in a systematic fashion. Once you "see" the noise (including frequencies and amplitudes) you have a handle to test changes immediately. Otherwise you may just continue the hit-and-miss experimentation. There must be something unique about your setup so that the standard recipes don't work. Right now you don't even know if this is high frequency noise (like from VFDs), if it is radiated or conducted, or if this is just AC leakage.

[bking1836]

I rigged up a long wire lead to one of the probes of the multimeter and checked continuity, which exists from the bare copper wire at the dust show all the way to the ground bus on the electrical panel. I don’t know enough to determine whether the continuity is “good” or however you’d measure it, but the multimeter beeps. Sometimes it’s a bit of a staccato beep. But it beeps.

Also grounded the frame.

Any ideas?

[EricSchimel]

Try it with the grounded frame and report back!

[bking1836]

Try it with the grounded frame and report back!

Grounding the frame didn’t stop the problem.

[Brady Watson]

Grounding the frame didn’t stop the problem.

How exactly did you ground the frame? Did you put the wire on an exposed bolt or did you drill into the steel & attach a lug/ring terminal etc?