90 Degree Conductors

[dvcraven052256]

Working on a project requiring all power load wiring to be #10AWG stranded copper wire and all feeder conductors to be rated 90deg C.

Not sure how to interrupt this.

Would this imply using 90Deg C column for ampacities?

 

[infinity]

No the conductor insulation is rated for 90° C like THHN.

 

[dvcraven052256]

Are most conductor insulation rated for 90 deg

 

[infinity]

Are most conductor insulation rated for 90 deg

For the most part yes. THHN/THWN-2 is 90° both wet and dry locations. THHN/THWN is 90° C dry, 75° C wet.

 

[winnie]

In general you won't use the 90C column for ampacities, because the ampacity of the conductors will be limited by the termination temperature ratings.

The exception (where you get to use the 90C values) is where you have adjustment for the total number of conductors in a raceway or adjustment for odd ambient temperatures. The other place you might use 90C values is for odd situations where you intentionally use 90C terminations to get maximum ampacity in a limited space (eg. there is an existing conduit that you _must_ use).

-Jonathan

 

[augie47]

As mentioned, the 90° is pretty much a "standard" but the #10 minimum branch circuit seems a bit over "overkill" and will be a bit more aggravating for device and fixture terminations,.

 

[infinity]

As mentioned, the 90° is pretty much a "standard" but the #10 minimum branch circuit seems a bit over "overkill" and will be a bit more aggravating for device and fixture terminations,.

At least they were smart enough to spec stranded #10's.