Feeders in metal trough

Grouch

Grouch

Senior Member
Location
New York, NY
Does anything in the NEC prohibit placing multiple feeders serving apartments in a common trough / wireway? Each apartment is fed by a 120/208 volt, single phase, three wire feeder, and it is being discussed to run all of them in a common trough.
 
Grouch1980 said:
Thank you sir.

I'm following Article 376... we'll have less than 30 current-carrying conductors, so no need to derate.
Click to expand...
If you have a barrier inside the troughs, it will create 2 separate compartments and you can have more wires on a single trough. So if you have a 10x10 wireway, you can put 60 wires (30 in each compartment) if you have a barrier inside the 10x10 wireway
 
Tainted said:
If you have a barrier inside the troughs, it will create 2 separate compartments and you can have more wires on a single trough. So if you have a 10x10 wireway, you can put 60 wires (30 in each compartment) if you have a barrier inside the 10x10 wireway
Click to expand...
I have argued that a barrier would make this into two separate raceways but there is no code wording that says such a thing. The NEC clearly defines a barrier in a box as creating what can be considered to be two separate boxes but that wording does not exist for a wireway.
 
infinity said:
I have argued that a barrier would make this into two separate raceways but there is no code wording that says such a thing. The NEC clearly defines a barrier in a box as creating what can be considered to be two separate boxes but that wording does not exist for a wireway.
Click to expand...
We did this in NYC and the inspector was ok with it, and also the NYC electrical committee says it's ok
 
At a job site someone mentioned to me there's a wireway application where you're permitted up to 40 CCC's without derating. Is this true or false? Have not been able to find it in the NEC.

EDIT: actually, true! It's in the NYC amendments (for auxiliary gutters):

Section 376.22—Add an Exception after subsection (B) to read as follows:
Exception: Metallic auxiliary gutters may contain up to 40 service entrance conductors without applying derating factors.
 
Last edited:
Grouch1980 said:
At a job site someone mentioned to me there's a wireway application where you're permitted up to 40 CCC's without derating. Is this true or false? Have not been able to find it in the NEC.

EDIT: actually, true! It's in the NYC amendments (for auxiliary gutters):

Section 376.22—Add an Exception after subsection (B) to read as follows:
Exception: Metallic auxiliary gutters may contain up to 40 service entrance conductors without applying derating factors.
Click to expand...
Yes that is typically used on a 4000 amp service with 10.sets of 600's. Note that it says 40 conductors not CCC's.
 
infinity said:
Yes that is typically used on a 4000 amp service with 10.sets of 600's. Note that it says 40 conductors not CCC's.
Click to expand...
so this means a ground conductor would count?

Edit: Acutally it says 40 service conductors, a ground conductor is not a service conductor so it shouldn't count?
 
infinity said:
Yes that is typically used on a 4000 amp service with 10.sets of 600's. Note that it says 40 conductors not CCC's.
Click to expand...
Tainted said:
so this means a ground conductor would count?

Edit: Acutally it says 40 service conductors, a ground conductor is not a service conductor so it shouldn't count?
Click to expand...
No, 10 sets (3Hots-1Neutral/set) equals 40 conductors. There are no EGC's ahead of the service disconnect. You're allowed up to 40 conductors, current carrying or not, then derating applies.
 
infinity said:
There are no EGC's ahead of the service disconnect.
Click to expand...
You are correct, I don't normally do it but I've seen it happen see pic below. Those service conductors are going to two sets of troughs and you can see the ground going with them. Pic is taken inside below a service end box.

IMG_9160.JPEG
 
Grouch1980 said:
At a job site someone mentioned to me there's a wireway application where you're permitted up to 40 CCC's without derating. Is this true or false? Have not been able to find it in the NEC.

EDIT: actually, true! It's in the NYC amendments (for auxiliary gutters):

Section 376.22—Add an Exception after subsection (B) to read as follows:
Exception: Metallic auxiliary gutters may contain up to 40 service entrance conductors without applying derating factors.
Click to expand...

I dont understand that. Why are they talking about auxiliary gutters in article 376? Shouldnt that exception be in 366? :unsure:
 
electrofelon said:
IF you read 366.2 it should be clear. Essentially a auxiliary gutter "extends" an enclosure, it isnt nippled to it. I dont know what they are trying to say with that exception. :unsure:
Click to expand...
so is an empty switchboard section an auxiliary gutter?
 
You must log in or register to reply here.
Top