Electrical Building Disconnect

[WA_Sparky]

I'm working on a project where there is a 100 sf structure adjacent to a large building for storage. Does anyone know if there are any exceptions regarding disconnecting means per NPFA 70 230.3 "One building or structure not to be supplied through another". The only loads for this building will be (1) receptacle and (1) light. If possible id like to avoid adding an additional disconnect, meter, panel, and 200' of conduit to shed. I'm hoping I might be able to get away with providing 30' trenched conduit from a panel within the main building, to a disconnect (located on the shed exterior) for the 1 circuit. Thanks in advance.

 

[david luchini]

I'm hoping I might be able to get away with providing 30' trenched conduit from a panel within the main building, to a disconnect (located on the shed exterior) for the 1 circuit. Thanks in advance.

230.3 wouldn't apply to this setup. You wouldn't be routing service conductors to the shed.

See Article 225, Section II.

 

[LarryFine]

In other words, just run a single circuit (even a single MWBC), and no disconnect is needed.

 

[david luchini]

In other words, just run a single circuit (even a single MWBC), and no disconnect is needed.

Which section does away with the disconnect requirement? I had that in my mind, too, but couldn't find it.

 

[jap]

I'm working on a project where there is a 100 sf structure adjacent to a large building for storage. Does anyone know if there are any exceptions regarding disconnecting means per NPFA 70 230.3 "One building or structure not to be supplied through another". The only loads for this building will be (1) receptacle and (1) light. If possible id like to avoid adding an additional disconnect, meter, panel, and 200' of conduit to shed. I'm hoping I might be able to get away with providing 30' trenched conduit from a panel within the main building, to a disconnect (located on the shed exterior) for the 1 circuit. Thanks in advance.

You're not providing power to the shed "through" the large building.
You're providing power to the shed "from" the large building.

You'll still need need a disconnect of some sort at the shed if you install more than 1 circuit to it, but, it sounds like you're not wanting to build a separate service for the shed, which you don't have to.


JAP>

 

[jap]

A disconnect such as a simple 1p switch may suffice if you're installing just 1 circuit, or, 1 MWBC which counts as 1 circuit.


JAP>

 

[don_resqcapt19]

Which section does away with the disconnect requirement? I had that in my mind, too, but couldn't find it.

While there is an exception, 250.32(A), Exception, that says a second building fed by a single circuit does not need a grounding electrode, there is no such exemption for the disconnect as far as I know.

225.36 Type of Disconnecting Means. The disconnecting means specified in 225.31 shall be comprised of a circuit breaker, molded case switch, general-use switch, snap switch, or other approved means. Where applied in accordance with
250.32(B), Exception No. 1, the disconnecting means shall be suitable for use as service equipment.

 

[david luchini]

While there is an exception, 250.32(A), Exception, that says a second building fed by a single circuit does not need a grounding electrode, there is no such exemption for the disconnect as far as I know.

Yes, that's what I was thinking of.

 

[WA_Sparky]

230.3 wouldn't apply to this setup. You wouldn't be routing service conductors to the shed.

See Article 225, Section II.

Perfect, so this is considered an accessory building, not service entrance, since its same owner and on the same meter. I'm permitted to supply (1) branch circuit to the given building and all i need is a disconnect at the shed building or structure (inside or on exterior).

Clarification for future projects:
Hypothetically, in the future, if i need to supply power to more than one circuit in an accessory building, the (1) supply circuit/feed verbiage in the code, I could provide a feeder to a small MCB panel at the shed (interior or exterior), then multiple branch circuits could be pulled from that given panel?

Thank you everyone for your input.

 

[david luchini]

Hypothetically, in the future, if i need to supply power to more than one circuit in an accessory building, the (1) supply circuit/feed verbiage in the code, I could provide a feeder to a small MCB panel at the shed (interior or exterior), then multiple branch circuits could be pulled from that given panel?

Yes

 

[LarryFine]

In other words, just run a single circuit (even a single MWBC), and no disconnect is needed.

My bad.

The disconnect can be as simple as a toggle switch.

 

[electrofelon]

Perfect, so this is considered an accessory building, not service entrance, since its same owner and on the same meter. I'm permitted to supply (1) branch circuit to the given building and all i need is a disconnect at the shed building or structure (inside or on exterior).

Clarification for future projects:
Hypothetically, in the future, if i need to supply power to more than one circuit in an accessory building, the (1) supply circuit/feed verbiage in the code, I could provide a feeder to a small MCB panel at the shed (interior or exterior), then multiple branch circuits could be pulled from that given panel?

Thank you everyone for your input.

For completeness, see 230.40 exception #3 for accessory structures to dwelling units which allows you to run a "service entrance" to each.