Generator 240V3P Delta High leg system

[CAC-ELEC]

I have a location and they want to install (1) generator on two services. The problem I've run into is that both the services are 240V 3P Delta High Leg. On one service they kept the "B" phase as the high leg throughout. On the second service at the meter equipment they switch the high leg to the C phase and run it through out. Am I allowed to swap the high leg from the C phase to the B phase between the generator disconnect and the ATS for that side? Will this have any issues with GND faults etc? I can't find anywhere in the code this is prohibited but it also doesn't seem to address this specific issue. I am making the generator a separately derived system and putting in 4-pole transfer equipment.

 

[ActionDave]

What kind of loads? Swapping phases on an existing building is a potentially dangerous undertaking.

 

[CAC-ELEC]

It's a winery, so some motor, a large chiller, receptacles / pump stanchions and lighting all existing. The generator is large and should have plenty of capacity to run all loads but they will also have some load shedding installed. Yes, I don't want to rewire one side of the facility (they actually have everything nicely labeled on every panel which leg is the high leg). I want to switch the high leg between the generator disconnect and the ATS (so I don't have to rewire) but I'm hesitant. Thanks for any feedback.

 

[zbang]

If you do move the high leg, roll all the phases instead of swapping two-
A B C -> C A B (or B C A)
not
A B C -> A C B
(maybe that's more my preference than any requirement, but it's better at distributing load)

That said, as long the generator matches the PoCo when it gets past the ATS, I don't see a problem.

 

[LarryFine]

It seems to me that, as long as you match the existing rotation and connections, the premises internal wiring is not relevant.

 

[synchro]

It seems to me that, as long as you match the existing rotation and connections, the premises internal wiring is not relevant.

Yes. As I see it, matching the connections of the actual high leg conductors that have 208V to neutral/gnd is the most critical thing regardless of the labeling. Then the other two phases need to be connected properly to obtain the existing rotation in each location as mentioned above.