Load Balancing

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sfordsr

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I have been called to do service at a commercial building with a 120/208 4-wire service and someone has installed a single phase back-up generator (19KW generator, 120/240 Volts) with an automatic transfer switch. My question is this - is it legal for them to take all of the customer requested loads off the 3 phase panel, and put them in a single phase panel?
They fed the single phase panel with a 2 pole 80 amp breaker in the 3 phase panel. The problem is the load on the main is now 0 amps on phase A, 58 amps on phase B, and 28 amps on phase C. The neutral is carrying 43 amps.
 
Not sure I exactly understand what was done but it sounds legal to me. I am assuming it is not affecting any MWBC that may have been in the 3 phase panel.
 
Load Balancing

The 3 phase is only used for A/C loads. That's why there was no load on A phase at the time of the reading.
 
sfordsr said:
The 3 phase is only used for A/C loads. That's why there was no load on A phase at the time of the reading.
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The AC will not be able to operate on standby power, but I am sure you are aware of this, what about the owner?

And if there were any 4 wire MWBC's they will need some changes.
 
IMO, this is not an nec violation however I am not sure why the loads are not distributed to the 3rd phase also.
 
Dennis Alwon said:
IMO, this is not an nec violation however I am not sure why the loads are not distributed to the 3rd phase also.
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Because they put them all in a single phase panel so they could back them up with the single phase generator.

Sounds like about all that was not put there was the three phase A/C.
 
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