Simply, and I mean very simply stated, your problem us that you have a transmitter creating interference and something that acts as receiver of the interference.
There may be no
single simple solution but what Gerry said is a start.
Most folks just don't understand interference and there are many books written on the subject. Hopefully the electrical and instrumentation folks will give you specifics on what to do.
Will not go into any detail, but, resolution of the problem is something like this:
- Identify the source of the problem
- Eliminate, isolate, reduce, contain the source of interference
- Provide protection from interference to any device
I have good grounding all the way back to the main panel of the building
That may be true from a purely electrical code point of view.
For interference, ( term used very loosely for the sake of simplicity) one
may want to provide a seperate ground system.
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Simple things to do and try:
- Make sure your wires are all shielded
- Provide a ground system for the shielding
- Move the electrical plug of the VFD to different outlet that is not part of the circuit
used for the PC or electrical supply to the router.
- Move the VFD as far away from the router as possible
- Keep wires to and from the vfd away from other wires
- Any control boards etc for the vfd should be enclosed
Only do one change at a time and see if it solves the problem
RICH