Box fill

[wireday]

I have 6 # 10s THHN coming into a4X4x2 1/4 J box through a 3/4 EMT. I have two 2 wire MC cables coming into this J box also,that makes 12 # 10s. 4 black,4 white,4 green. Can I add anymore, would I need a bigger box to add a circuit or a box extension?

 

[cpinetree]

Try this

Try this

Electrical box fill calculator: http://www.constructionmonkey.com/calculations/electrical/boxfill.aspx

 

[infinity]

I have 6 # 10s THHN coming into a4X4x2 1/4 J box through a 3/4 EMT. I have two 2 wire MC cables coming into this J box also,that makes 12 # 10s. 4 black,4 white,4 green. Can I add anymore, would I need a bigger box to add a circuit or a box extension?

According to T314.16(A) you're allowed 12-#10 conductors. Did you do a calculation?

 

[1793]

I have 6 # 10s THHN coming into a4X4x2 1/4 J box through a 3/4 EMT. I have two 2 wire MC cables coming into this J box also,that makes 12 # 10s. 4 black,4 white,4 green. Can I add anymore, would I need a bigger box to add a circuit or a box extension?

Don't the Equipment Grounding conductors, green, only get counted once?

 

[GoldDigger]

In terms of ampacity, none of them count. In terms of conduit or box fill, they all take up space. Bare EGCs take less space than insulated ones would.

Sent from my XT1080 using Tapatalk

 

[infinity]

All of the EGC's count as one single conductor for box fill. There is no distinction made in 314.16(B) for bare or insulated conductors.

 

[Smart $]

In terms of ampacity, none of them count. In terms of conduit or box fill, they all take up space. Bare EGCs take less space than insulated ones would.

Sent from my XT1080 using Tapatalk

But according to box fill requirements, all EGC's count as one "volume" using the largest of the lot. Each additional set, such as isolated EGC's, count as one additional "volume".

OP has 9 "volumes" of box fill at 2.5 in? each [unless he failed to enamor any I-EGC(s)]. That's 22.5 in? total. OP said 2-1/4 deep 4sq, but 2-1/8 deep is standard at 30.3 in?. He has room for 3 more #10 volume allowances.