Camara Practice Problems Chpt. 65 #7

[Chester95]

I have a question regarding the books answer to this problem. It states that for this case, circuits less than 100A you need to use the 60degC column for cable ampacities. Is this because they only give the terminal ratings of the OCPD and not the field devices? The code will allow the use of 75degC as long as the equipment, etc is rated appropriately.

Thanks!

 

[Flyer_PE]

That agrees with my reading of NEC 110.14.c.1. Since the temperature rating for the end device is not listed, you have to conservatively assume that it is only good for 60 deg.

If both the end device and the OCPD are rated for 75 deg., the cable can be chosen using the 75 deg. ampacity.