ray cyr
Senior Member
- Location
- Yakima, Wash.
The plant I work in has three large, three phase transformers. Each one feeds its? own switchgear. The serving utility tells us that all three are Delta secondary configurations. I am told that each is an ungrounded system.
On system ?A? at disconnects fed from its? switchgear, when I measure voltage I read 480 volts from line A-B, line B-C and line A-C. When I measure voltage between line A and the disconnect cabinet, I read 480 volts. Same thing for line B. Between line C and the can I read 4 volts (nope, not a typo).
I get the same results on system ?C?.
On system ?B? I read 480 volts line to line and 277 volts from each phase to the can.
I know what my thoughts are on this and they don?t agree with what I am being told?
I will appreciate your thoughts on this.
Thanks,
Ray
On system ?A? at disconnects fed from its? switchgear, when I measure voltage I read 480 volts from line A-B, line B-C and line A-C. When I measure voltage between line A and the disconnect cabinet, I read 480 volts. Same thing for line B. Between line C and the can I read 4 volts (nope, not a typo).
I get the same results on system ?C?.
On system ?B? I read 480 volts line to line and 277 volts from each phase to the can.
I know what my thoughts are on this and they don?t agree with what I am being told?
I will appreciate your thoughts on this.
Thanks,
Ray