Branch circuits in 84 circuit panels

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Tinmaniac

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Fort Myers Fl
I have two 42 circuit 3 phase panel boards nippled together. The panels have feed through lugs and are fed from one 400A enclosed circuit breaker. Because of changes in the field I need to bring branch circuits that are piped into the first section to breakers in the second section. They pass through a nipple that do not contain the main lug jumpers. Is this a code violation?
 

roger

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Fl
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Perfectly fine and even if they were in the same raceway as the feeders it would be fine as well.

Roger
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Welcome!

It only matters that all conductors of a given BC or MWBC pass through the same nipple and all terminate in the same panel.
 

infinity

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New Jersey
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I have two 42 circuit 3 phase panel boards nippled together. The panels have feed through lugs and are fed from one 400A enclosed circuit breaker. Because of changes in the field I need to bring branch circuits that are piped into the first section to breakers in the second section. They pass through a nipple that do not contain the main lug jumpers. Is this a code violation?

Done all of the time. Take a look at 312.8. Your nipple if 24" or less can have a fill of up to 60% and no derating.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Correct, and don't forget a neutral when used is one of those circuit conductors.
All means all.

Having said that, if the conductors pass through the same nipple as the main conductors, the neutral could land in the other panel.*

*This is electrically speaking, not code-compliance speaking; if you draw it out, you'll see what I mean. The same thing usually happens when adding a generator transfer switch.
 

kwired

Electron manager
Location
NE Nebraska
All means all.

Having said that, if the conductors pass through the same nipple as the main conductors, the neutral could land in the other panel.*

*This is electrically speaking, not code-compliance speaking; if you draw it out, you'll see what I mean. The same thing usually happens when adding a generator transfer switch.
I know what all means, just had to throw a comment in there because some easily forget the neutral is part of the circuit.

* pretty sure I know what you are getting at, and it can be a little complicated depending on how things are arranged.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
pretty sure I know what you are getting at, and it can be a little complicated depending on how things are arranged.
Example: Let's say power enters Panel A, and feed-thru to Panel B. Now, let's say Circuit A1 needs to be moved to Panel B, but the neutral is left in Panel A.

As long as the same nipple is used, there will still be no net current issues, because the line current will still cancel, and the neutral current won't use the nipple.

Had A1's neutral been moved, it would merely be cancelled because it would have used the same nipple as the feeder. It's important to always use the same nipple.
 

kwired

Electron manager
Location
NE Nebraska
Example: Let's say power enters Panel A, and feed-thru to Panel B. Now, let's say Circuit A1 needs to be moved to Panel B, but the neutral is left in Panel A.

As long as the same nipple is used, there will still be no net current issues, because the line current will still cancel, and the neutral current won't use the nipple.

Had A1's neutral been moved, it would merely be cancelled because it would have used the same nipple as the feeder. It's important to always use the same nipple.

Net current isn't an issue if you moved B1 to panel A either if the ungrounded branch circuits pass through same nipple as the feeder as the feeder neutral is carrying the unbalance.

Having current on feeder neutral to panel B when the ungrounded conductors open supplying panel B are open is seen as an issue for some, may or may not be an issue with NEC, I'd have to look harder to give a definite answer to that.
 
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