Box fill calculation question

[mapesken]

Box fill confusion
Currently planning electrical for my 40 x 40 metal building.

I am running 4 circuits 14ga THHN through 3/4 EMT into junction box represented by the blue square.

8 CCC in conduit 70% derate so 25 amps allowed at 90C 25a x 0.7= 17.5 amps
15 amp breaker due to max allowable over current protection

The question is do the two circuits that run through the box (no splices) count as 4 or 8?

This will most likely be going into a 3-gang box may upgrade to 4-gang just because.

Does everything look up to NEC code? (Clay county Florida)

Did I miss anything?

Sorry about the crude pic and huge post if I have learned anything here It's that insufficient information is not an option.

 

[Charles (in GA)]

Wires that pass thru without splices count as one each. Wires that splice and continue on count as two.

I prefer ½ EMT with fewer wires, and more runs of conduit. That will be a packed box, as you are at the max for a 2-1/8 deep 4x4. Only saving grace is you gain a small amount with the cover.

 

[sands35]

I found a 6x6 electrical box at:

http://www.garvinindustries.com/electrical-junction-boxes/6-square-junction-boxes/1-1-2-to-3-deep

No relation.

It worked well for a couple boxes with lots of wires and a 8-3 wire to a weld outlet.

 

[MTW]

Stuffing Boxes

Layout planning suggestions.

To avoid stuffing device boxes to the fullest extent possible. Use an additional pull box before the device box, for pulling through the conductors not required in the device box.

The upper pull box can be located higher than the device box, and a drop made to the device box, with only the wiring required for the particular devices.

Saves extra conduit runs, cost is minimal, simplifies servicing devices later. It's a bit more cumbersome locating the additional pull box and uses slightly more wire and labor.

Still need to derate the conductors though.

MTW Ω

 

[mapesken]

Thanks for the great ideas

I found NEC table 314.16(a)

A 4-11/16 x 4 11/16 x 2-1/8 is 42 cubic inches and will hold 21 #14's.

I didn't want to to too large these are wall mounted this box in particular holds a GFI outlet that will protect two outlets on the ceiling for cord reels as well as another GFI that protects other wall outlets.

Even if I split the outlets into their own 4" boxes I would still be 1 CCC over max fill.

Plus I didn't want to have to climb up a ladder to reset the outlet.

 

[mapesken]

Sorry here is a pic of my project