Derating
#1
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Derating
I was reading the code and I don't under stand what derating is and how it applies.
Why is it allowable to derate neutral, relative to the line wires?
Why is it allowable to derate neutral, relative to the line wires?
#2
Derating is a compensation for the inability to radiate heat because the cables or wires are close together or are in a high heat area. The ampacity is reduced.
The neutral is sometimes allowed to be smaller than the ungrounded conductors due to not all circuits need a neutral.
The neutral is sometimes allowed to be smaller than the ungrounded conductors due to not all circuits need a neutral.
#3
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Typically, you only have to be concerned with derating if you're running more than 9 current carrying (hot & neutral) wires in one channel (usually conduit). When you pull NM-B through studs/joists, you want to limit it to no more than 3 (or 4) cables through a single hole across a few studs or joists.