Thanks for your reply.
I thought that maybe because the equipment grounding conductor was sized according to the amperage of the overcurrent device in T250.122 at some point with derating it might call a larger wire than is shown in T250.122.
Thanks
Let's be clear about our use of terminology here.
But that is not a process of derating the EGC, since as I said already the EGC does not have an ampacity rating.
- IF because of having more than three current-carrying conductors in the same raceway you have to derate the conductor's ampacity,
- AND IF because of this you have to use a larger size wire for the ungrounded conductors,
- THEN you also have to use a larger EGC.
Sorry I took so long to get back.
I read 250.122(B) and I understand it to say if I have to increase the size of the ungrounded conductors because of derating or volt drop then I should increase the size of the equiptment grounding conductor proportionately. So its
got nothing to do with carrying current unless there is a fault.
Do you agree?
That is always true for an equipment grounding conductor.So its got nothing to do with carrying current unless there is a fault. Do you agree?