Three Phase Xfer but Single Phase Panel

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Swanny

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Vineland NJ
Hello All. Our NJ State run facility just purchased an outdoor prefabbed double stall restroom. All I needed to do was run power out to it and connect to existing panel. Our facility wanted a three phase 200 amp panel instead of the 100 amp single phase that was standard. The thinking was for any future projects...(it will never happen...overkill). The bathroom is over 600 ft from any power source so we ran 3 phase 480v (voltage drop adjusted) and are gonna install a 3 phase 75kva transformer next to the bathroom and pipe it in. Cut and dry Right? Bathroom just came today and has a 200 amp single phase panel in it. Oooops. Wire is already pulled to transformer pad from main, and returning the transformer the state bought will take an act of God. My option is...demo the panel and install a three phase panel, but my boss asked if I could pull the wires but only hook it up single phase to have ready sooner. I have never even thought about it. I know its possible. It obviously will be 208/120 with a wire taped off in the transformer and panel as a "spare". Is this legal? Before anyone asks the loads are crazy small. 3 small 15amp 240v heaters is the biggest load. And I would label the voltage at the panel. I dont mind changing the panel but it would be quicker and cheaper (new panel) to use existing but is it code? Thanks in advance. ~Ed
 
IMO, you would be limited to 50kva of load of the transformer using only two legs which would be adequate for your 200 amp panel and more than adequate for the actual load
 
Looks okay to me and I agree with the 50 kva load limit noted above. Your heaters won't put out quite to rating I'd say. When I worked for the power company we did this surprisingly often on temp services and not long ago we converted a house from single phase 120/240 to this. Long story though.

Ben

Ben
 
I'm guessing the transformer is D/y, with the star point internally connected? No chance you could reconnect the trafo as a center-tapped delta and leave the wild leg at the TX? I know it's a long-shot, but I figured I'd ask.



SceneryDriver
 
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