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Trough Sizing

WCEI

WCEI

Senior Member
Location
Central Virginia
Occupation
President/Owner, Wayne Cook Electric, Inc.
Situation:

Power Company CT cabinet. I must exit the top of the CT cabinet with the customer side service conductors. My preference is to use a 4” nipple to go up into this trough. The trough will extend past the side of the CT cabinet so that I can drop down in 4” conduit to a trough that will be below my disconnects. (Before you ask, and it has no bearing on the question I’m about to ask anyway, because of a design problem I can not extend the top trough over and feed my disconnects from the top.)

Does 314.28 apply to sizing the trough? Or am I missing something. If I must use 314.28 then I will have a gigantic junction box that looks like crap.
4” x 6 times the trade size = 24” plus 4” for the other opening in the same wall.

I swear I have put a ton of troughs up in my career and I’ve never put one up this large in this deminision. Have I always done it wrong but never been caught, or am I having a senior moment?
 
augie47

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
It doesn't change your situation but I think this would actually be Art 376 installation.
The wording of 376.23 gives you the same leeway,
(might be relevant if an inspection is involved)
 
electrofelon

electrofelon

Senior Member
Location
Cherry Valley NY, Seattle, WA
Eddie702 said:
Don't know what code he is on but 2023 doesn't have 366.2. What is the difference between a wireway and a Aux Gutter? Same products is it not?
Click to expand...
Sorry, Im in the 2017. I think they moved all the definitions up to the front? Anyway:

366.2 Definitions.
Metal Auxiliary Gutter. A sheet metal enclosure used to supplement wiring spaces at meter centers, distribution centers, switchgear, switchboards, and similar points of wiring systems. The enclosure has hinged or removable covers for housing and protecting electrical wires, cable, and busbars. The enclosure is designed for conductors to be laid or set in place after the enclosures have been installed as a complete system.

Metal wire ways are not required to be listed, so you could use an auxiliary gutter as a wire way. As far as the other way around, using a wire way as an auxiliary gutter, I'm not sure, they do have some listing requirements:


366.6 Listing Requirements.
(A) Outdoors. Nonmetallic auxiliary gutters installed outdoors shall be listed for all of the following conditions:
(1) Exposure to sunlight
(2) Use in wet locations
(3) Maximum ambient temperature of the installation
(B) Indoors. Nonmetallic auxiliary gutters installed indoors shall be listed for the maximum ambient temperature of the installation.
 
augie47

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
A few years back Ryan Jackson had a pretty good article regarding wireways vs auxiliary gutters,
It included a rather descriptive photo....
1717726469174.jpeg
 
W

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
jaggedben said:
I agree too.
Click to expand...
I understand that may be the intention, but I'm having trouble seeing the definitions as saying that. Are you and others reading "supplement wiring spaces" to imply that the enclosure must to be contiguous with the "meter center, distribution center, switchgear, (or) switchboard" enclosure?

I guess I can see that, although my first instinct is to read it the same as "provide supplemental wiring space" at such equipment, which to me would only require it to be in the general vicinity (366.12 provide a distance limit of 30') of such equipment.

Cheers, Wayne
 
E

Eddie702

Licensed Electrician
Location
Western Massachusetts
Occupation
Electrician
If I understand what @augie47 posted is that a Aux gutter must be immediately adjacent maybe even attached to the meter cabinet and that a wireway can be connected to the meter cabinet with pipe or a nipple. Either way the requirement for "6x the raceway size" seems to be negated by 376.23 A which seem to be in conflict with B . A which refers to refers to 3.126A wire bending space. and B which refers to 3.14 28 A 2 which refers you back to 6x the raceway size.

Very confusing
 
W

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
jaggedben said:
I agree too.
Click to expand...
OK, I think I'm with you now, the key point is the sentence "The enclosure is designed for conductors to be laid or set in place after the enclosures have been installed as a complete system." Since enclosure (singular) means the auxilliary gutter, then enclosures (plural) must include the enclosure of the "meter center, distribution center, switchgear, (or) switchboard." Which means the above sentence implies continuity, if "laying in or setting" rules out pulling through a conduit nipple.

That's a lot of work for a single s to do, so I think it could be clearer.

Cheers, Wayne
 
W

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Eddie702 said:
. . . 376.23 A which seem to be in conflict with B . A which refers to refers to 3.126A wire bending space. and B which refers to 3.14 28 A 2 which refers you back to 6x the raceway size.
Click to expand...
I think the idea is that based on the wording of 376.23(B), it is only requiring us to look at the part of 314.28(A) that covers "the distance between raceway and cable entries enclosing the same conductor" and not all of 314.28(A).

Cheers, Wayne
 
E

Eddie702

Licensed Electrician
Location
Western Massachusetts
Occupation
Electrician
So to size a wireway would you size it by using 376.23A wire bending space or 376.23B which refers you back to 6x the raceway size. This is assuming a typical job with say 2 disconnects mounted to a wireway with nipples between the wireway and the disconnects and tw0 pipes out of the wireway side or back. Not the ends.

Seems like there is something I am not getting
 
W

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Eddie702 said:
So to size a wireway would you size it by using 376.23A wire bending space or 376.23B which refers you back to 6x the raceway size.
Click to expand...
No, it refers you to (1) for straight pulls "the length of the box or conduit body shall not be less than eight times the metric designator (trade size) of the largest raceway" and (2) for angle pulls "The distance between raceway entries enclosing the same conductor shall not be less than six times the metric designator (trade size) of the larger raceway." Not the rest of 314.28(A)(2).

Cheers, Wayne
 
J

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
wwhitney said:
I understand that may be the intention, but I'm having trouble seeing the definitions as saying that. Are you and others reading "supplement wiring spaces" to imply that the enclosure must to be contiguous with the "meter center, distribution center, switchgear, (or) switchboard" enclosure?

...
Click to expand...
wwhitney said:
OK, I think I'm with you now ...
Click to expand...

Frankly I think you'd be less confused if you were intimately familiar with the parts like those of us saying it's Article 376. Simply, 'trough' is almost always slang for a 376 wireway. Moreover, he said he's putting a "nipple" between it and the CT cabinet, which is almost always slang for a single piece of RMC (Article 344) with appropriate fittings. So he's already left the CT cabinet with one wiring method and is simply continuing his run with another. He's not supplementing the wiring space at the CT cabinet. And yes, to my understanding an auxilliary gutter would be contiguous with the CT cabinet, probably made by the same manufacturer? I've never installed an auxilliary gutter in my career, and I'm not sure I've ever even seen one. But I install a wireway on almost every job nowadays, and they are all over the place.
 
electrofelon

electrofelon

Senior Member
Location
Cherry Valley NY, Seattle, WA
I actually kind of can't imagine using an auxiliary gutter these days, with them being so uncommon that most people haven't even heard of them, and with most inspectors being super trigger happy on "listing violations". I can just see the ensuing battle with the inspector after I chop off the bottom of a cabinet and custom fabricate an auxiliary gutter to it. 😳
 
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