Main emergency conduit

[anbm]

If the emergency generator locates outside the building and main emergency panel (first panel downstream of EG) locates on 3rd floor, will the conduits from the generator to this panel need to be concrete encased? Thanks

 

[charlie b]

This is not unique to emergency systems. Anytime you bring power into a building, you need to have a means for disconnecting the power. That device (breaker, fuses, unfused disconnect switch, whatever) has to be either outside the building or inside nearest the point of entrance of the conductors. If you put a disconnect outside the building, then the conductors going to the first panel don't have to be concrete encased. If there is no disconnect outside the building, then by encasing the conduits in concrete (minimum 2 inches) you get to consider that the conduits are still "outside" the building. That way, when you get the conduits into the third floor electrical room, it is only then that they are considered to have entered the building, and you can take credit for a main breaker in that first panel as being the required disconnecting means.

 

[don_resqcapt19]

You would need to comply with the rules in 700.9(D) for fire protection of the emergency feeder, assuming this is an Article 700 application.

 

[OTT2]

I addition to what others have said, if this generator is "within sight of" and the disconnecting means on or at the generator is "suitable for use as service equipment" then a disconnecting means nearest the point of entrance is not required if you comply with 700.12 (B)(6).

 

[cowboyjwc]

I was gonna say most generators have an over current device on them.

 

[don_resqcapt19]

I addition to what others have said, if this generator is "within sight of" and the disconnecting means on or at the generator is "suitable for use as service equipment" then a disconnecting means nearest the point of entrance is not required if you comply with 700.12 (B)(6).

Not exactly correct. The disconnect at the generator must be within sight from the building, not just the generator itself.

 

[OTT2]

Not exactly correct. The disconnect at the generator must be within sight from the building, not just the generator itself.

...if this generator is "within sight of" and the disconnecting means on or at the generator is "suitable for use as service equipment"...

Isn't that what I said?

 

[don_resqcapt19]

...if this generator is "within sight of" and the disconnecting means on or at the generator is "suitable for use as service equipment"...

Isn't that what I said?

To me you are saying that only the generator must be within sight. The rule says that the disconnect itself must be within sight. A disconnect inside of the generator enclosure is not within sight from the building, unless there is a window. Likewise a disconnect on the side of the generator that is facing away from the building is not within sight from the building.

700.12(B)(6) Outdoor Generator Sets. Where an outdoor housed generator set is equipped with a readily accessible disconnecting means located within sight of the building or structure supplied, an additional disconnecting means shall not be required where ungrounded conductors serve or pass through the building or structure. The disconnecting means shall meet the requirements of 225.36.

 

[ceb58]

To me you are saying that only the generator must be within sight. The rule says that the disconnect itself must be within sight. A disconnect inside of the generator enclosure is not within sight from the building, unless there is a window. Likewise a disconnect on the side of the generator that is facing away from the building is not within sight from the building.

I agree with what Don has said. All inspectors I have ran across have ruled this way. And from what I have seen the gen. must be ordered with a service rated breaker and window to comply.