Extension Box - Overextension

[Lon Culbertson]

Existing building circuit in the original 4" square box was just long enough to make up in the box. The three extension boxes were added to connect this circuit to the new work associated with the building remodel.

The stacked extension box assembly is to be foamed in with insulation; hence the reason for the stacked assembly of 4" square box and (3) extension boxes.

NEC or U.L. Listing violations?

 

[infinity]

The limiting factor is meeting the required conductor length not the number of extension collars.

 

[kwired]

Existing building circuit in the original 4" square box was just long enough to make up in the box. The three extension boxes were added to connect this circuit to the new work associated with the building remodel.

The stacked extension box assembly is to be foamed in with insulation; hence the reason for the stacked assembly of 4" square box and (3) extension boxes.

NEC or U.L. Listing violations?

300.14.

you must have at least 6 inches of free conductor in the box, and for small box like that you must have at least 3 inches of conductor that can extend beyond the front of the box.

 

[GoldDigger]

300.14.

you must have at least 6 inches of free conductor in the box, and for small box like that you must have at least 3 inches of conductor that can extend beyond the front of the box.

And from the OP's description, I infer that the wire nuts or whatever is used are buried in the deepest box, which will be totally unreachable. At best pull new wires for that run?

 

[sameguy]

Someone pull out the picture of the 5' extension ringamabob!

 

[480sparky]

Someone pull out the picture of the 5' extension ringamabob!

 

[sameguy]

Thanks, I never get tired of that!

 

[LarryFine]

It's more like a 4 x 4 x 12 trough.

 

[electrofelon]

how are the face up and face down ext rings fastened together? Are they just floating?

 

[Craigv]

how are the face up and face down ext rings fastened together? Are they just floating?

I was pondering this as well. The two that face each other would be "assembled" first, which could be dicey unless you drill out the threads in one box. From there you would be able to "twist n snap" the rest using the keyhole slots.

Sure is a stretch regarding accessibility of the connections....:lol:

This has me wondering whether the extension listings have a stated limit of how many can be stacked.

 

[kwired]

And from the OP's description, I infer that the wire nuts or whatever is used are buried in the deepest box, which will be totally unreachable. At best pull new wires for that run?

Only entry so far is in the second from "front" box so that helps some. Just because the ends are in the deepest part of the box don't make them non compliant, how much can be pulled out is the key here.

 

[480sparky]

I was pondering this as well. The two that face each other would be "assembled" first, which could be dicey unless you drill out the threads in one box. ...................

Run an 8-32 screw from one extension ring right into the other one.

 

[Craigv]

Run an 8-32 screw from one extension ring right into the other one.

I would drill out one side's threads for a clearance fit, just so you aren't trying to screw one threaded tab into another threaded tab. Overthinking it for sure, especially for a Rube Goldberg solution...