jszrom
Member
- Location
- New York, NY
Hey code-heads!
Been trying to find the code section that actually allows this. The passed down method for wire sizing says you can use the 90 degree C column if you have 90 degree C wire, 75 degree C terminations and you are derating due to temperature or number of conductors in a raceway. Then you take the LOWER of either the derated 90 degree C value or the non-derated 75 degree C value.
The problem is I can't find where it allows this in the code. 110.14(C)(1)(b)(2) sort of implies this but doesn't say anything about derating. 320.80(A) specifically allows you to do this for AC type cable. And 334.80 allows this for NM type cable. But where in the code does it allow this for other cable types (THHN, THWN-2, etc.)?
Thanks!
Been trying to find the code section that actually allows this. The passed down method for wire sizing says you can use the 90 degree C column if you have 90 degree C wire, 75 degree C terminations and you are derating due to temperature or number of conductors in a raceway. Then you take the LOWER of either the derated 90 degree C value or the non-derated 75 degree C value.
The problem is I can't find where it allows this in the code. 110.14(C)(1)(b)(2) sort of implies this but doesn't say anything about derating. 320.80(A) specifically allows you to do this for AC type cable. And 334.80 allows this for NM type cable. But where in the code does it allow this for other cable types (THHN, THWN-2, etc.)?
Thanks!
