awg necessary on disconnect and subpanel

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hardworker

Senior Member
I am installing a 200 amp 1 phase disconnect within 2ft of an existing 400 amp main panel. The disconnect will feed a 200 amp subpanel about 60 ft. away.

Using 3/0 for the hots and #4 for ground. All copper.

Does code want something heavier between disconnect and main?

Thanks
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
I am installing a 200 amp 1 phase disconnect within 2ft of an existing 400 amp main panel. The disconnect will feed a 200 amp subpanel about 60 ft. away.

Using 3/0 for the hots and #4 for ground. All copper.

Does code want something heavier between disconnect and main?

Thanks

Just need the feeder breaker in the 400A to be large enough to protect the 3/0 wire. Which in your case would be a 200A breaker.
 

infinity

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Location
New Jersey
Occupation
Journeyman Electrician
If this is a tap the EGC should be #3, its size based on the 400 amp OCPD ahead of the feeder that you're tapping.
 

Smart $

Esteemed Member
Location
Ohio
Is there not a feeder breaker in the 400A panel?

It is not obvious why you are installing a fused disconnect switch within 2ft of another disconnecting means (the breaker in the panel).
 

Glock23gp

Member
Location
United States
I think he's saying he's pulling off the 400amp. Hitting a 200amp disco feeding a 200amp panel 60` away. If that's the case you fall within the 10' tap rule.

Sent from my SAMSUNG-SM-T337A using Tapatalk
 

Smart $

Esteemed Member
Location
Ohio
I think he's saying he's pulling off the 400amp. Hitting a 200amp disco feeding a 200amp panel 60` away. If that's the case you fall within the 10' tap rule.
I realize he may be doing a feed thru [tap]. Just looking for clarification.
 

hardworker

Senior Member
Is there not a feeder breaker in the 400A panel?

It is not obvious why you are installing a fused disconnect switch within 2ft of another disconnecting means (the breaker in the panel).


There is not a feeder breaker in the 400 amp panel. I will have to tap it. It is an older installation.
 
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