20 amp 120 volt circuit to feed 100 amp Main Breaker panel

[sparkync]

I have a customer who just had a utility building delivered and set up next to his inground pool. He has a electrical panel at his pool with only 1 space left in the panel. He wants to come out of that panel and just feed 120 volts to his building. He is using the building mostly for storage and does not need anything but the lights and the (2) receptacles that were already prewired. The building came with a 100 amp. electrical panel with a main breaker, and (2) 15 amp single pole breakers for the lights and receptacles. In order to get him just the 120 volts for the panel, I'll have to jumper to the (2) legs together. Is there anything in the code that says I can't do this? The panel itself will be protected by a 20 amp single pole GFI circuit. The 100 amp main breaker in the panel will actually just be a disconnect. I will drive the 2 ground rods and the neutral and ground will be separated. I know this is an odd set up, but his main electrical panel is about 150 ft. from the building. See anything wrong about this installation?
Permit has already be obtained for the building and electrical.
Thanks

 

[LarryFine]

1. The line lugs are probably not rated for two wires, but you can use a wirenut and pigtails.

2. The grounding is not required when a single branch circuit is the supplying power source.

 

[sparkync]

Thanks Larry, and yes I found it and actually had it circled in my code book, but just forgot it (about the grounding).

 

[jaggedben]

You should put a placard or label on it that warns not to install multi-wire branch circuits.

One could argue that the panel is being used contrary to its listing, and this violates 110.3(B). One could probably argue the opposite, too.

The grounding is required if there are two branch circuits in the panel, as your supply to the panel then becomes a feeder.

 

[sparkync]

According to my understanding and the wording of 250.32A, exception, of the 2011 Code ( I don't have a current code book available right now), that...."A grounding electrode shall not be required where only a single branch circuit, including a multiwire branch circuit, SUPPLIES, the building or structure and the branch circuit includes an equipment grounding conductor...." There are two circuits in the panel that was prewired, but only one that supplies the building. If the two circuits that are prewired is a problem, I could just make them one since there are only 2 outlets and 3 lights in the building. Am I misunderstanding the term, "Supplies"?
Thanks

 

[david luchini]

According to my understanding and the wording of 250.32A, exception, of the 2011 Code ( I don't have a current code book available right now), that...."A grounding electrode shall not be required where only a single branch circuit, including a multiwire branch circuit, SUPPLIES, the building or structure and the branch circuit includes an equipment grounding conductor...." There are two circuits in the panel that was prewired, but only one that supplies the building. If the two circuits that are prewired is a problem, I could just make them one since there are only 2 outlets and 3 lights in the building. Am I misunderstanding the term, "Supplies"?
Thanks

The building is being supplied by a feeder regardless of how many circuits are in the panel...the exception does not apply.

 

[infinity]

According to my understanding and the wording of 250.32A, exception, of the 2011 Code ( I don't have a current code book available right now), that...."A grounding electrode shall not be required where only a single branch circuit, including a multiwire branch circuit, SUPPLIES, the building or structure and the branch circuit includes an equipment grounding conductor...." There are two circuits in the panel that was prewired, but only one that supplies the building. If the two circuits that are prewired is a problem, I could just make them one since there are only 2 outlets and 3 lights in the building. Am I misunderstanding the term, "Supplies"?
Thanks

As David stated you do not have a branch circuit supplying the panel but a feeder unless you eliminate the OCPD's at the remote building.

Feeder. All circuit conductors between the service equipment, the source of a separately derived system, or other power supply source and the final branch-circuit overcurrent device.

 

[LarryFine]

It's a feeder, all right. If the shed's panel contained a single breaker, it could possibly be considered a disconnect.

 

[blkmagik21]

I have a customer who just had a utility building delivered and set up next to his inground pool. He has a electrical panel at his pool with only 1 space left in the panel. He wants to come out of that panel and just feed 120 volts to his building. He is using the building mostly for storage and does not need anything but the lights and the (2) receptacles that were already prewired. The building came with a 100 amp. electrical panel with a main breaker, and (2) 15 amp single pole breakers for the lights and receptacles. In order to get him just the 120 volts for the panel, I'll have to jumper to the (2) legs together. Is there anything in the code that says I can't do this? The panel itself will be protected by a 20 amp single pole GFI circuit. The 100 amp main breaker in the panel will actually just be a disconnect. I will drive the 2 ground rods and the neutral and ground will be separated. I know this is an odd set up, but his main electrical panel is about 150 ft. from the building. See anything wrong about this installation?
Permit has already be obtained for the building and electrical.
Thanks

I’d have to lookup the reference but for a circuit supplying a subpanel I’m quite sure the minim size is 30 amps. If you don’t need any 229 you are not required to install the second phase. But you will still need ground rods and a ground wire


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[david luchini]

I’d have to lookup the reference but for a circuit supplying a subpanel I’m quite sure the minim size is 30 amps.

I don't believe there is any requirement to use a 30A circuit.

 

[charlie b]

I’d have to lookup the reference but for a circuit supplying a subpanel I’m quite sure the minim size is 30 amps.

I don't believe there is any requirement to use a 30A circuit.

I believe blkmagik21 is thinking about 225.39(B). It has a minimum requirement of 30 amps for a two-circuit installation at a separate building. But that limit applies to the rating of the disconnecting means, not to any overcurrent protective device.