Building Fed w/ 240 single Phase, add 480V feeder?

Sparky2791

Sparky2791

Senior Member
Location
Northeast, PA
Occupation
Electrical Design
I have a project with a concession stand that has a 240V, single phase service. The concession stand is between 2 Tennis courts. Near the building (About 150' away) is a 277/480V panel for different service on site, this is an athletic complex. They want to add lights to the Tennis Courts. The 240V service is not large enough to handle the load. Am I permitted to bring a 277/480V feeder to the building to feed a panel where I can serve the lighting and some additional electric heaters they want to add?
 
kwired said:
225.30(E) would allow it.
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That is the section that had me scratching my head because it applies when more than one feeder or branch circuit is supplying a single building or structure. In my example, the building would be supplied with a service , directly from the POCO, and a feeder from a panel that is part of a different service so the building is only being fed with one feeder.

Is it acceptable to have a feeder supplying a building that has a service. The different characteristics (277/480) helps but this seems an odd situation not fully covered by the NEC or I am just missing it.

Thanks!
 
You might look into the monthly charges for the 240 service, vs the annual transformer kwh losses of a 480:240 transformer, abandoning the 240 service and installing a 480:240 transformer might be more economical.
 
For the 2026 NEC I attempted to get the CMPs behind Articles 225 and 230 to coordinate on whether it is acceptable to have a building supplied by both one service and one feeder. They each declined to change their articles at all, on the basis that Article 225 only covers feeders and so shouldn't mention services, and vice versa.

My conclusion is that therefore it's fine for any building to be be supplied by one feeder and one service, even at the same voltage. There is certainly nothing in the NEC that explicitly prohibits it.

Cheers, Wayne
 
Is there a reason why you need to land on the building before refeeding the lights? Are they currently 120V and you are trying to tie into the existing conduit?

Where are the time clocks?

Try intercepting the UG run with splices in a hand hole and small fuse D/Cs at the time clock. 240.21(B)(5) If the time clock is at the tennis courts and not on the building.
 
tortuga said:
You might look into the monthly charges for the 240 service, vs the annual transformer kwh losses of a 480:240 transformer, abandoning the 240 service and installing a 480:240 transformer might be more economical.
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This is a 'band aid' situation. The 480V panel has limited capacity available too. One of those, what are our options to do this quick and cheap clients. Not one of those , what is the right way to do this clients. So, offering options.
 
tortuga said:
You might look into the monthly charges for the 240 service, vs the annual transformer kwh losses of a 480:240 transformer, abandoning the 240 service and installing a 480:240 transformer might be more economical.
Click to expand...
Probably the biggest load in there is the deep fryer, and that might be capable of being reconfigured to 480. If so the transformer needed might be a 10 KVA at most
 
wwhitney said:
For the 2026 NEC I attempted to get the CMPs behind Articles 225 and 230 to coordinate on whether it is acceptable to have a building supplied by both one service and one feeder. They each declined to change their articles at all, on the basis that Article 225 only covers feeders and so shouldn't mention services, and vice versa.

My conclusion is that therefore it's fine for any building to be be supplied by one feeder and one service, even at the same voltage. There is certainly nothing in the NEC that explicitly prohibits it.

Cheers, Wayne
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Glad I am not the only one who feels that way about those 2 Code sections and the ambiguity it leaves in these situations! As always AHJ could 'gripe' but I would challenge them to point to the section of the code that prohibits it. Thanks for the reply!
 
wwhitney said:
For the 2026 NEC I attempted to get the CMPs behind Articles 225 and 230 to coordinate on whether it is acceptable to have a building supplied by both one service and one feeder. They each declined to change their articles at all, on the basis that Article 225 only covers feeders and so shouldn't mention services, and vice versa.

My conclusion is that therefore it's fine for any building to be be supplied by one feeder and one service, even at the same voltage. There is certainly nothing in the NEC that explicitly prohibits it.

Cheers, Wayne
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What was their panel statement? Would the disconnects need to be grouped?
 
tortuga said:
What was their panel statement?
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I submitted 3 PIs:

1) 225.30 Change the title to "Number of Branch Circuit or Feeder Supplies." to make it clear there was no prohibition on a service as well.
CMP response: The proposed revision does not add clarity because this is already in the article referring to outside branch circuits and feeders.

That can be seen as saying the change would have no effect, because it's already clear there is no prohibition on a service as well.

2) 225.30 Opposite effect: change to "A building or other structure that is supplied by a service, branch circuit or feeder shall not be supplied by another branch circuit or feeder unless permitted in 225.30(A) through (F)."
CMP response: "The building is only served by a branch circuit or feeder and not a service. Services are not included in the scope of Article 225."

The first sentence could be seen as saying the building couldn't also be supplied by a service, while the second sentence suggests the opposite.

3) 230.2 Equivalent change to (2) above: change to "A building or other structure supplied by a service, branch circuit, or feeder shall not be supplied by another service unless permitted in 230.2(A) through (D)."
CMP response: "Article 230 addresses service, and does not include feeders and branch circuits."

This suggests that it's fine to have one feeder and one service without needing to meet any of the specified conditions.

Cheers, Wayne
 
Wow @wwhitney your like our own MH forums CMP advocate, thanks.
I recall we had a thread about that some time back and it was unclear. That sure clears it up.
 
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