Conductor sizing Sub A/C panel

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Dennis Alwon

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Chapel Hill, NC
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Retired Electrical Contractor
Yes, as long as the neutral is not smaller than the GEC you are good. At first I thought you were using copper but I realize those are alum. sizes.
 

infinity

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Location
New Jersey
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Journeyman Electrician
For #4/0 Al your connected load would need to be 180 amps or less to use a 200 amp OCPD.
 

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
For #4/0 Al your connected load would need to be 180 amps or less to use a 200 amp OCPD.
That is correct however for the op's understanding, the OCPD may still be 200 amp as long as the load is under 180amps as Trevor stated. 240.4(B)
 

Mr. Tuttle

Member
Location
wisconsin
Connected load

Connected load

Yes, I think the connected load was 130 amps roughly. All 15SEER A/C units. Since this was all going to be piped in my concern was the neutral. We "only" needed a neutral for the 1-20 amp general purpose gfci for A/C's. No other branch circuits will ever be added to this panel. So, 2,400 watts or 20 amps on the neutral. I was curious as to what the smallest neutral that can be ran with that setup and egc to match.
 

kwired

Electron manager
Location
NE Nebraska
Yes, I think the connected load was 130 amps roughly. All 15SEER A/C units. Since this was all going to be piped in my concern was the neutral. We "only" needed a neutral for the 1-20 amp general purpose gfci for A/C's. No other branch circuits will ever be added to this panel. So, 2,400 watts or 20 amps on the neutral. I was curious as to what the smallest neutral that can be ran with that setup and egc to match.

Neutral can not be smaller than the required equipment grounding conductor.

See 215.2 for feeders, I am not finding anything specific to branch circuits but am pretty certain that same thing applies to branch circuits.

See 250.24(C) for grounded service conductors - generally you are looking at not being any smaller than required grounding electrode conductor.
 
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