Neutral Size

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It was for odd order harmonics during the paranoria years and it has gotten permanately stuck in some designers minds.

Roger
 
Commonly known as a 200% neutral. Technically the ungrounded conductors have been upsized so the EGC may be too small.
 
infinity said:
Commonly known as a 200% neutral. Technically the ungrounded conductors have been upsized so the EGC may be too small.
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I thought in most cases the neutral was the grounded conductor.

You bring up a point though, do I have to increase the size of the EG when the neutral is oversized but not the Phase conductors? I wouldn’t, but I’ve been wrong at least once....in the last 10 minutes.
 
ptonsparky said:
I thought in most cases the neutral was the grounded conductor.

You bring up a point though, do I have to increase the size of the EG when the neutral is oversized but not the Phase conductors? I wouldn’t, but I’ve been wrong at least once....in the last 10 minutes.
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250.122(B) references increasing the EGC only when the ungrounded conductors are increased in size.
 
infinity said:
Technically the ungrounded conductors have been upsized so the EGC may be too small.
Click to expand...
We don't know that. The OCPD could be a 100 amp breaker. That properly corresponds with a #2 ungrounded conductor and a #8 EGC.

 
charlie b said:
We don't know that. The OCPD could be a 100 amp breaker. That properly corresponds with a #2 ungrounded conductor and a #8 EGC.
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Could be or maybe not. #3 THHN is a 100 amp conductor so #2 would be an increase in size from #3.
 
infinity said:
Could be or maybe not. #3 THHN is a 100 amp conductor so #2 would be an increase in size from #3.
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I agree, EGC likely needs proportional increase in size in this case unless we can come up with a detail that says #3 isn't a 100 amp conductor for this application.
 
ptonsparky said:
I thought in most cases the neutral was the grounded conductor.

You bring up a point though, do I have to increase the size of the EG when the neutral is oversized but not the Phase conductors? I wouldn’t, but I’ve been wrong at least once....in the last 10 minutes.
Click to expand...
Scratch this....now I see where you came up with oversized phase conductors.:dunce:
 
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