Off Grid Building Disconnecting Means

[mbrooke]

Do buildings with on-site power generators require a disconnecting means? If so does it have to accessible? Sign? 710.1 just points me to the rest of the code.

 

[don_resqcapt19]

Per 90.3 the rules in Chapters 1-4 apply to a Chapter 7 installation unless the Chapter 7 article says that they don't.
However, since it doesn't have a service the code language is not clear. The disconnect rules in 230 would not apply because those rules only apply to services.
It appears 225.31 would require a disconnect for a building supplied by an on-site power generation system.

 

[mbrooke]

Per 90.3 the rules in Chapters 1-4 apply to a Chapter 7 installation unless the Chapter 7 article says that they don't.
However, since it doesn't have a service the code language is not clear. The disconnect rules in 230 would not apply because those rules only apply to services.
It appears 225.31 would require a disconnect for a building supplied by an on-site power generation system.

Hhmmm-




If I'm reading it right, 225.31 only applies if the conductors pass through the exterior, ore come from a generating hut next to the property?

 

[don_resqcapt19]

Hhmmm-

View attachment 2555448


If I'm reading it right, 225.31 only applies if the conductors pass through the exterior, ore come from a generating hut next to the property?

The requirement for a disconnect in 225.30 says supply or past through....does not talk about where the supply comes from. The rule still applies where the generation is within the building.

However, you are correct, that creates difficulty with the location rule in 225.31, as there is no point of entrance for the supply conductors if they originate within the structure. This location difficulty does not eliminate the requirement found in 225.30.

 

[mbrooke]

The requirement for a disconnect in 225.30 says supply or past through....does not talk about where the supply comes from. The rule still applies where the generation is within the building.

However, you are correct, that creates difficulty with the location rule in 225.31, as there is no point of entrance for the supply conductors if they originate within the structure. This location difficulty does not eliminate the requirement found in 225.30.

Alright. So, the question is- where do I put the main disconnect? What if there is more than one (ie 8 generators)? Would I be violting code having more than 6 throws?

 

[david luchini]

Article 225 is "Outside Branch Circuits and Feeders." I don't see how the 225.31 would apply if the generator was within the building.

 

[mbrooke]

Article 225 is "Outside Branch Circuits and Feeders." I don't see how the 225.31 would apply if the generator was within the building.

Thats what I'm thinking.

 

[david luchini]

445.18 would require a disconnecting means for the generator. It doesn't say anything about location.

 

[mbrooke]

445.18 would require a disconnecting means for the generator. It doesn't say anything about location.

I see that now. And of course a remote stop switch outside the electrical room?