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UPS output waveform

UPS output waveform

UPS output waveform

(OP)
I have an engineer that has come back from a site with the waveforms from a 50KVA UPS that were captured on his scope. The phase to phase waveform is sinusoidal without a great deal of distortion. The unit did not seem to be loaded anywhere near the system capabilities but the engineer did not check the crest factor of the load.
However, the phase to neutral waveform is almost triangular in shape on all three phases. Any ideas why the phase to phase voltage is OK but the phase to neutral waveform is so distorted?

UPS Service Manager http://www.nolanpower.com

RE: UPS output waveform

Third-tone injection is a common technique to get full phase-phase voltage. But this does not sound quite like that. What do your other UPS-es look like?

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: UPS output waveform

OK. Better talk to the manufacturer then.
I still think it is in good order and that the third tone injection is causing the waveform. No need to worry, I think.

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

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