Thanks. I tend to agree with you guys, but this guy says their company does a lot of engineering for sensitive equipment--Honeywell and some others-- and says somethings dealing with inductance, capacitance (unspecific) he may not have known exactly, can cause this situation. When they removed the second ground all together, the unit works fine.
Like I said, I don't see how a short piece of wire can change all of this (especially when it is a #4 in a 200amp panel or a direct connection thru the panel enclosure itself) I guess I'd need to see the technical specs.
He said they were measuring a 1/2 amp on the ground wire. I don't know how they know there isn't current on the conduit.
Where's Scott? He usually has a complex answer.