Frank44
Member
- Location
- Oakland CA
I have the following installation:
2-pole 240V breaker with two #2 AWG and one #6 AWG EGC feeding a Phase Perfect phase converter which requires a 125 AMP service and outputs 58A, 240V, 3 phase.
The phase converter supplies a 100A 240V distribution panel (no main breaker) with #4 AWG.
On the distribution panel there is one 3-pole 240V 30A breaker supplying a table saw, with a 30A 240V 3-pole non-fused disconnect ahead of the saw.
Also on the distribution panel there is an existing 3-pole 240V 60A breaker with #4 AWG supplying a 240 to 480V step up 30KVA transformer (delta-delta). The 480V output of the xfmr goes to a fused, 3-pole 480V disconnect and has one load, a shaper rated at 20 full load amps (it is soft start).
Only one piece of equipment will be used at a time.
Two questions:
1. Do I need main breaker on the 240V 3 phase distribution panel (i.e. on the load side of the phase converter)?
2. The 30KVA transformer does not have a corner, or ?B? ground. There are no ground indicating devices. I believe one or the other is required even if the output is hard-wired to a single load. Is the corner ground preferable? Should it go to H2? (xfmr is a step up).
Thank you.
2-pole 240V breaker with two #2 AWG and one #6 AWG EGC feeding a Phase Perfect phase converter which requires a 125 AMP service and outputs 58A, 240V, 3 phase.
The phase converter supplies a 100A 240V distribution panel (no main breaker) with #4 AWG.
On the distribution panel there is one 3-pole 240V 30A breaker supplying a table saw, with a 30A 240V 3-pole non-fused disconnect ahead of the saw.
Also on the distribution panel there is an existing 3-pole 240V 60A breaker with #4 AWG supplying a 240 to 480V step up 30KVA transformer (delta-delta). The 480V output of the xfmr goes to a fused, 3-pole 480V disconnect and has one load, a shaper rated at 20 full load amps (it is soft start).
Only one piece of equipment will be used at a time.
Two questions:
1. Do I need main breaker on the 240V 3 phase distribution panel (i.e. on the load side of the phase converter)?
2. The 30KVA transformer does not have a corner, or ?B? ground. There are no ground indicating devices. I believe one or the other is required even if the output is hard-wired to a single load. Is the corner ground preferable? Should it go to H2? (xfmr is a step up).
Thank you.