FEEDER SIZING LESS THAN 100A

[gnu_mike]

I thought I had read on this forum that sizing feeders for less than 100A demand utilizes the 60 degree C column from table 310-16.
Is this right?

 

[ryan_618]

Re: FEEDER SIZING LESS THAN 100A

Sort of. Take a look at 110.14(C).

 

[charlie b]

Re: FEEDER SIZING LESS THAN 100A

Yes. 110.14(C)(1)(a)

 

[gnu_mike]

Re: FEEDER SIZING LESS THAN 100A

Thanks!

 

[steve66]

Re: FEEDER SIZING LESS THAN 100A

In reality, I think most terminations are rated for 75 degrees. For example, Square D type NQOD breakers have a note:

10-30 amp breakers are suitable for use with 60 or 75 degree conductors. 35-125 amp breakers are suitable for use with 75 degree conductors.

I assume that means you can use the 75 deg. column if both ends of the wire are landed on NQOD breakers.

STeve

 

[612278]

Re: FEEDER SIZING LESS THAN 100A

Hello -

Dont forget some zinsco's all rated at 40%C.
STEVE