Box fill Question

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wireday

Senior Member
Location
New England
Occupation
Master electrician
Does a male EMT fitting count? also MC speed connectors ,the kind with a set screw clamp. Most everything on these is outside the box.
 

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Sorta retired........
Does a male EMT fitting count? also MC speed connectors ,the kind with a set screw clamp. Most everything on these is outside the box.

314.16 (B) No allowance shall be required for small fittings such as locknuts and bushings.

314.16 (B) (2)
No allowance shall be required for a cable connector with its clamping mechanism outside the box.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
how silly is all that and yet the clamps that are part of the plastic boxes need to be counted as conductor fill. I would bet that there is less area from those plastic tabs that a connector thread and locknut.
 

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Sorta retired........
how silly is all that and yet the clamps that are part of the plastic boxes need to be counted as conductor fill. I would bet that there is less area from those plastic tabs that a connector thread and locknut.
Absolutely! Makes no sense......
The old work boxes with the metal clamps I can see but not the plastic tabs. Lots of times they get knocked out completely. When that happens I just staple it really straight and close to the box. Never have been turned down for a missing plastic tab.
However the clamps in the 2 gang and up boxes don't tend to fall out as easily.
But do each one of those count as a wire or just the ones we use?
 
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kwired

Electron manager
Location
NE Nebraska
how silly is all that and yet the clamps that are part of the plastic boxes need to be counted as conductor fill. I would bet that there is less area from those plastic tabs that a connector thread and locknut.
Really? I have never counted them. With those kind of boxes they give you the volume, and often the max number of conductors allowed. When they give you both the max number of conductors matches up with calculations that disregard the clamps. Any time a box is marked with it's volume I have always assumed it accounted for anything included in the box but you had to count anything that is field added.

Absolutely! Makes no sense......
The old work boxes with the metal clamps I can see but not the plastic tabs. Lots of times they get knocked out completely. When that happens I just staple it really straight and close to the box. Never have been turned down for a missing plastic tab.
However the clamps in the 2 gang and up boxes don't tend to fall out as easily.
But do each one of those count as a wire or just the ones we use?

Those clamps are required to secure the cable to the box on other than what is essentially described as one gang device boxes.

Read the last sentence of 314.17. The exception that follows allows the one gang box to not have a clamp but the cable must be fastened within 8" of the box instead of the usual 12" if the cable is not "secured" to the box.
 
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