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Wire fill rules for ******* connecting enclosures?

MatBirch

Well-known member
Joined
Oct 10, 2013
Messages
419
Location
Filer, Idaho
An older Journeyman I worked for once told me that for "short ******* between enclosures" that there are no fill limits. "stuff all you want in there if you need to"...
Any truth to that?

I have a 12x12 hoffman box on the inside wall of my home, directly behind the panel. There is only a 2" ****** through the wall, and it's getting pretty full. It's about 5-6" long.
The previous jerk just combined a ****-ton of grounds and neutrals in the hoffman with wire nuts. I'm trying to remedy that and so I'm adding quite a few wires through the ******. At this point I can still just "slide it through", it's not like I have to work real hard at it. I have about five more circuits to do though, and most of those will be all new, so 3 wires per...

If I can't keep adding, what's my best choice? There really isn't room in the panel itself for a larger ******. Can I add a second? Come through elsewhere in conduit? Keep the **** in the box the way it is? :headshake

Thanks.
 
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exranger06

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Joined
Aug 9, 2015
Messages
1,686
Location
CT
I'm not sure what the rule is regarding ******* and conduit fill.

You can add another conduit/****** to the box. You just need to make sure that all conductors of a particular circuit are in the same conduit. In other words, don't put the hot leg of a circuit through one conduit and the neutral of that same circuit through the other conduit. The hot leg and neutral both need to go through the same conduit.

You can convert some existing circuits to multi-wire branch circuits, and that would reduce the number of neutrals you have to put through the conduit. Just put a handle tie on 2 adjacent breakers (as long as they're the same amperage) and use a single neutral wire for both breakers (again, make sure all hot wires for both breakers and neutral are all in same conduit) Then as soon as the wires get to the junction box, you can split the neutral off into two separate wires.

I wouldn't bother running an individual ground wire back to the panel for each circuit. I'd have no problem wire-nutting a bunch together in the junction box and running a single ground back to the panel. You could probably even install a ground bar in the junction box and just land all the grounds to that.
 

Terry D

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Joined
Mar 25, 2015
Messages
2,202
Location
St. Louis, MO.
******* not longer than 24" are allowed to have a 60% fill. Chapter 9, table 1, note 4 of the NEC. You can not just jam them full. Also ******* not longer than 24" are not subject to conductor ampacity derating
 
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toplessHO

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Oct 20, 2014
Messages
14,086
Location
central florida
******* not longer than 24" are allowed to have a 60% fill. Chapter 9, table 1, note 4 of the NEC. You can not just jam them full. Also ******* not longer than 24" are not subject to conductor ampacity derating

what many dont realize is that 60% is actually quite a bit when you consider the space between all those round objects.
 

teamextreme

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Joined
Aug 10, 2013
Messages
867
Location
Lakewood, CO
I wouldn't waste my time running a bunch of separate ground wires, no reason to do that. Just make sure they're made up well in the j-box, or good advice above to install a ground bar in the j-box.
 
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