2008 NEC handbook, exhibit 700.5

[MikeOlson]

As shown in exhibit 700.5, I have multiple feeders into a building from a generator, and terminating on individually enclosed circuit breakers inside. Two of the feeders are parallel conductor sets each rated for 600A, and the other feeder is one set of conductors rated for 150A. The 600A feeders are (2) sets of 4#350+G, and the 150A feeder is 4#1/0+G. There is a total number of (5) conductors per phase for the three feeders.

If the generator breaker is 1200A, and has 4 lugs per phase rated for #3/0-500MCM, can I terminate the (5) sets of conductors at the generator breaker? If not, please let me know your thoughts on the conductor termination methods at the generator breaker.

Thanks

 

[chris kennedy]

If the generator breaker is 1200A, and has 4 lugs per phase rated for #3/0-500MCM, can I terminate the (5) sets of conductors at the generator breaker? If not, please let me know your thoughts on the conductor termination methods at the generator breaker.

That size generator should have room for polaris taps.

Edit: You may have other design issues here. Are you using 240.21 here.

 

[MikeOlson]

Yes, I was taking 240.21(B)(5) into account.

 

[Cold Fusion]

... Two of the feeders are parallel conductor sets each rated for 600A, and the other feeder is one set of conductors rated for 150A.

...There is a total number of (5) conductors per phase for the three feeders.

...please let me know your thoughts on the conductor termination methods at the generator breaker.

I'm guessing a 480V, 800kw.

Consider installing a j-box with 1200A bus, right next to the gen. Run 4-350 from the gen to the j-box. Run the individual feeders from the j-box.

cf