Section 230.82, 230.85 and 225.32

[Dennis Alwon]

I believe, in the 2023, we can install an emergency disconnect and run 3 wires to an interior panel in a home and treat it as one would a service, ie, grounds and neutrals connected together.

What happens when we have a remote building (garage) with a 200 amp service and an emergency disconnect and meter mounted at that building. Can I run 3 conductors to the house or as 250.32 states do I need 4 conductors?

 

[wwhitney]

Depends on whether the supply to the house originates upstream (utility-side) of the garage enclosure with the Main Bonding Jumper. If it does, the supply to the house is a service and has to comply with Article 230. If it does not, the supply is a feeder and has to comply with Article 225, including running an EGC.

Cheers, Wayne

 

[david luchini]

I'm not sure you would need the emergency disconnect at the remote building. Run the service conductors from the single drop to the dwelling and provide an emergency disconnect there (or a service disconnect).

 

[Dennis Alwon]

I'm not sure you would need the emergency disconnect at the remote building. Run the service conductors from the single drop to the dwelling and provide an emergency disconnect there (or a service disconnect).

I get that but I was doing a hypothetical.

 

[wwhitney]

I get that but I was doing a hypothetical.

The presence or absence of an emergency disconnect on the garage doesn't matter for your hypothetical. Although the emergency disconnect would be a convenient place to splice your service conductors if you wish to run a service to the house, rather than a feeder.

Cheers, Wayne

 

[Dennis Alwon]

Depends on whether the supply to the house originates upstream (utility-side) of the garage enclosure with the Main Bonding Jumper. If it does, the supply to the house is a service and has to comply with Article 230. If it does not, the supply is a feeder and has to comply with Article 225, including running an EGC.

Cheers, Wayne

That's the oddity. We are so used to adding a disconnect and running 4 wires to a remote structure that it seems wrong to run a 3 wire.

 

[Dennis Alwon]

The presence or absence of an emergency disconnect on the garage doesn't matter for your hypothetical. Although the emergency disconnect would be a convenient place to splice your service conductors if you wish to run a service to the house, rather than a feeder.

Cheers, Wayne

Let's just say it is just a disconnect. In that case we need 4 wires to the house. If I use an emergency disconnect then I can run 3 wires to the house... seems wrong to me..

 

[david luchini]

That's the oddity. We are so used to adding a disconnect and running 4 wires to a remote structure that it seems wrong to run a 3 wire.

You could have an emergency disconnect at the house, the service disconnect inside the house in the main panel, and you would run 3 wire to the remote structure, as it is still service conductors.

 

[wwhitney]

That's the oddity. We are so used to adding a disconnect and running 4 wires to a remote structure that it seems wrong to run a 3 wire.

For a single family dwelling, 230.40 Exception 3 has always allowed you to put a junction box upstream of the garage service disconnect to splice to a second set of service conductors for the house.

Let's just say it is just a disconnect. In that case we need 4 wires to the house. If I use an emergency disconnect then I can run 3 wires to the house... seems wrong to me..

So that's an interesting question--are you even allowed to have an emergency disconnect on the garage under 230.85? Or as 230.85 is only for "one and two family dwelling units," is the first disconnect on the garage necessarily the service disconnect?

Even in the case the garage has only one disconnect (which would be the service disconnect) if it is outside you could splice the service conductors in that enclosure but on the line side of the OCPD and run service conductors to the house.

Cheers, Wayne