Emergency power feeder

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Greenboy

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We are installing a 800 amp emergency generator with main breaker in Generator.

This feeder runs into the building stubbed into electrical room #1, then ran approximately 35' from Electrical room #1 to Electr4ical room #2 to the Generator panel (GDP). From GDP, to other panels (Life Safety, Critical branch panel, Equipment branch).

Electrical room #1 = main electrical switch gear.
Electrical room #2 = Where the Emergency panel located.

The electrical engineer is stating that the feeders from the generator needs to follow the 15' rule, like unfused conductors rule. Is this true?


Also, the engineer is stating that Data cabling are not allowed in the electrical room #1. Is this true?



The reason we are stubbing into Electrical room #1, is because Electrical room #2 would put us 15' below grade. Just in case you were wondering.
 
Greenboy said:
The electrical engineer is stating that the feeders from the generator needs to follow the 15' rule, like unfused conductors rule.
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As a point of clarification for the benefit of the membership, although the NEC only vaguely states that a building's main disconnecting means is to be "inside nearest the point of entry," Washington State sets the limit at 15 feet.

Let me probe a couple areas. First, where is the generator, in relation to the building that contains the two electrical rooms? There are circumstances in which the generator breaker can serve as the building's disconnecting means for the backup power system. If you don't meet those requirements, then I believe you will need to install a disconnect (not necessarily fused) either outside or within 15 feet of the point of entry. You can satisfy the 15 foot limit by encasing the feeder in conduit, but I think that would not be my first choice.

Secondly, please describe the generator distribution panel. Does it have a main breaker of its own? Does it have separate vertical sections to feed the three transfer switches? Have you looked into selective coordination between breakers within the GDP and the generator breaker?

 
charlie b said:
As a point of clarification for the benefit of the membership, although the NEC only vaguely states that a building's main disconnecting means is to be "inside nearest the point of entry," Washington State sets the limit at 15 feet.

Let me probe a couple areas. First, where is the generator, in relation to the building that contains the two electrical rooms? There are circumstances in which the generator breaker can serve as the building's disconnecting means for the backup power system. If you don't meet those requirements, then I believe you will need to install a disconnect (not necessarily fused) either outside or within 15 feet of the point of entry. You can satisfy the 15 foot limit by encasing the feeder in conduit, but I think that would not be my first choice.

Secondly, please describe the generator distribution panel. Does it have a main breaker of its own? Does it have separate vertical sections to feed the three transfer switches? Have you looked into selective coordination between breakers within the GDP and the generator breaker?
Click to expand...

I think you mean encasing in concrete.
 
charlie b said:
As a point of clarification for the benefit of the membership, although the NEC only vaguely states that a building's main disconnecting means is to be "inside nearest the point of entry," Washington State sets the limit at 15 feet.

Let me probe a couple areas. First, where is the generator, in relation to the building that contains the two electrical rooms? There are circumstances in which the generator breaker can serve as the building's disconnecting means for the backup power system. If you don't meet those requirements, then I believe you will need to install a disconnect (not necessarily fused) either outside or within 15 feet of the point of entry. You can satisfy the 15 foot limit by encasing the feeder in conduit, but I think that would not be my first choice.

Secondly, please describe the generator distribution panel. Does it have a main breaker of its own? Does it have separate vertical sections to feed the three transfer switches? Have you looked into selective coordination between breakers within the GDP and the generator breaker?
Click to expand...

To answer question #1 -> The generator is placed approximately 150 lineal feet from the building(Electrical room #1, & #2) it is feeding. The generator has a main breaker. And we also have the load banking requirement as well.

Answer to #2 Panel GDP has a 800 amp main breaker. Not following the vertical sections though. Would you mind pointing out the code article that indicates this?. However, each breakers takes up panel spaces as follow. breaker 1(1,3,5,2,4,6), Breaker 2(7,9,11,8,10,12), and breaker 3 (13,15,17, 14,16,18). Selective coordination has been an ongoing discussion and close, with few ongoing changes.
 
Washington has some rules on generators, in the WAC,
A disconnect is not required at the building if the generator is within 15 ft of the building
the generator disconnect can be used as a disconnect even though it does not meet the requirements in 225
Emergency ckts are identified with orange, not red

And the 2017 NEC has a requirement for a back up to an emergency generator for when it is out of service..
 
Greenboy said:
To answer question #1 -> The generator is placed approximately 150 lineal feet from the building(Electrical room #1, & #2) it is feeding. The generator has a main breaker.
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Take a look at 700.12(B)(6). Do you meet the exception to this article? If not, then you might have an issue to work out.

 
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