Bjarney, I see now your line about the harmonic content. Sorry I didn't notice it earlier. I have comprehension problems when reading from a CRT screen!
I'm sure the UPS equipment is generating all sorts of jagged waveforms, there is no doubt that high harmonics are there. But I wonder if this is destructive, or if it is just an issue of some vibration coming off some component in the trip unit that responds resonantly to the high harmonics.
Will replacing the breaker with like kind actually solve the noise issue, or will it just re-occur with the new breaker? When I was checking this out, the air conditioning equipment associated with the computer loads were not on, so the load was very light..pretty much UPS's and a small transformer fed panel. Perhaps with additional loading the noise gets swamped out, I don't know. Wattsup, did the load distribution on your breaker changeouts change at all for the elevator issue? I suppose, in your case, the load was probably just the elevator drives, and the load was still the same. Any feedback from the supplier or from Westinghouse about why the noise was generated?
Just don't want to spend gobs of time traveling and replacing parts if the noise is just an artifact of the particular design of the Westinghouse breaker.
