When derating conductors of different sizes you would use the table 5a 5b but my question is when you do this you still need to go to 310 for derating?I only ask because a apprentice working with me was taught that when it was done in 5a chapter 9 it is already derated.I don't recall that and thought was used for unlike conductors mainly not derating.
derating conductors
- Thread starter tommy
- Start date
- Status
bphgravity
Senior Member
- Location
- Florida
Re: derating conductors
I don't know how you would use Table 5 in Chapter 9 for derating purposes? Table 5 is used for sizing conductors to be used in raceways. Maybe you are talking about Annex C which does not consider derating.
I don't know how you would use Table 5 in Chapter 9 for derating purposes? Table 5 is used for sizing conductors to be used in raceways. Maybe you are talking about Annex C which does not consider derating.
Re: derating conductors
That's what I say but I figure I would check.What brought this is lets say you had a 4" conduit and installed 9 #12 gauge conductors does the size of the conduit make a difference.I was taught n
ver three conductors in any raceway you must derate.Right?
That's what I say but I figure I would check.What brought this is lets say you had a 4" conduit and installed 9 #12 gauge conductors does the size of the conduit make a difference.I was taught n
ver three conductors in any raceway you must derate.Right?bphgravity
Senior Member
- Location
- Florida
Re: derating conductors
Yes, you are correct. The code does not specify adjustments for larger than required raceway sizes. It is conceivable that 9 #12 AWG conductors in a 4" raceway would have enough heat disipation to not require a 30% reduction in current-carrying capacity, but the code does not allow this.
Yes, you are correct. The code does not specify adjustments for larger than required raceway sizes. It is conceivable that 9 #12 AWG conductors in a 4" raceway would have enough heat disipation to not require a 30% reduction in current-carrying capacity, but the code does not allow this.
- Status