Down sizing neutral conductor

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C3PO

Senior Member
Location
Tennessee
Actually That's a pretty good idea.:smile:

Well I brought it up at my meeting and they all agreed that it complied. One guy complained and said what about if they try to add new loads to it? I told him that I had learned the "you can't inspect what they might do." (I heard that here):D

Just curious, did anyone in the meeting bring up 250.122(B) ???
 

C3PO

Senior Member
Location
Tennessee
Yes, but it wasn't relivent to the question, as the wires were sized properly for the OCP.

IMHO the wires are not sized properly to the OCP

Am I missing something here? 215.2(A)(1) tells us our feeder grounded conductor can not be smaller then required by 250.122. We have 4awg protected at 60A so per 250.122(B) our EGC would have to upsized as well.

41740/2624= 1.59

10380 * 1.59 = 16504.2

which means it would have to be at least a 8 awg not 10 awg


In my mind it is relevant to the question. What am I overlooking ??? :-?
 

markstg

Senior Member
Location
Big Easy
IMHO the wires are not sized properly to the OCP

Am I missing something here? 215.2(A)(1) tells us our feeder grounded conductor can not be smaller then required by 250.122. We have 4awg protected at 60A so per 250.122(B) our EGC would have to upsized as well.

41740/2624= 1.59

10380 * 1.59 = 16504.2

which means it would have to be at least a 8 awg not 10 awg

In my mind it is relevant to the question. What am I overlooking ??? :-?

C3PO has nailed it. The #4 conductors have been increased in size relative to the 60A CB.

That's why we don't see this kind of stuff, cause its wrong (IMHO).
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
We have 4awg protected at 60A so per 250.122(B) our EGC would have to upsized as well.

which means it would have to be at least a 8 awg not 10 awg

In my mind it is relevant to the question. What am I overlooking ??? :-?
Only that I thought the OP was asking about the neutral, not the EGC.
 

C3PO

Senior Member
Location
Tennessee
Only that I thought the OP was asking about the neutral, not the EGC.

That is true but:

The size of the feeder circuit grounded conductor shall not be smaller than that required by 250.122, except that 250.122(F) shall not apply where grounded conductors are run in parallel.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
good catch, C3PO !
My mind told me that 250.122 was referenced to voltage drop, but it simply stares "where increased" for any reason.
 
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