Gutter at a Service

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Miami, FL
We are repairing and replacing a big section of an existing service at a shopping center, the plans shows to replace the existing 1200A main disconnect (fused at 900A), from there we are planing to have a gutter next to the disconnect and all the meter / disconnect for each spaces at the bottom, (very typical) the gutter will connect on the side of the disconnect with (3) 3" conduits, this is typical done wit a 12x12xL gutter, the plan review is not agree with the gutter size, he is making us to size the gutter according to the 314.28, instead of the 376.
I always seen this type a service done this way, the engineer on the design has talked to the plans review and is not willing to approved it, what I missing here, this a typical service, are all this services on violations? Is the reviewer correct?
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
We are repairing and replacing a big section of an existing service at a shopping center, the plans shows to replace the existing 1200A main disconnect (fused at 900A), from there we are planing to have a gutter next to the disconnect and all the meter / disconnect for each spaces at the bottom, (very typical) the gutter will connect on the side of the disconnect with (3) 3" conduits, this is typical done wit a 12x12xL gutter, the plan review is not agree with the gutter size, he is making us to size the gutter according to the 314.28, instead of the 376.
I always seen this type a service done this way, the engineer on the design has talked to the plans review and is not willing to approved it, what I missing here, this a typical service, are all this services on violations? Is the reviewer correct?
It is my opinion that where conductors enter and leave a wireway, then that wire way is being used as a pull box and the sizing rules in 314.28 apply. This is not a common reading of the code (and somewhat surprised that the plan reviewer has read it the way I do), but the issue is conductor damage when they are being installed. This damage typically happens when you are trying to force the end of the loop into the enclosure that is too small....that is one that does not comply with 314.28.

I have submitted a public input for the 2017 code on this issue. We will see what the CMP has to say.
 
Location
Miami, FL
After Bob input, I looked at the 366.2, there is the answer of what we are doing, spoke to the plan review and hi said he review as a wireway because is how the engineer name it, we are reviewing the plans and call it "auxiliary gutter" to be cover the 366, be meeting with him tomorrow, let you know.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
After Bob input, I looked at the 366.2, there is the answer of what we are doing, spoke to the plan review and hi said he review as a wireway because is how the engineer name it, we are reviewing the plans and call it "auxiliary gutter" to be cover the 366, be meeting with him tomorrow, let you know.
I don't think you are using the item in question to "to supplement wiring spaces at meter centers, distribution centers, switchgear, switchboards, and similar points of wiring systems." If you are not doing that, you don't have an auxiliary gutter.
 
Location
Miami, FL
I don't think you are using the item in question to "to supplement wiring spaces at meter centers, distribution centers, switchgear, switchboards, and similar points of wiring systems." If you are not doing that, you don't have an auxiliary gutter.

I am connecting all the meters to a main disconnects (and then from each meters it'l go to disconnects for each bay), inside the main disconnect there is not enough room for the (6) meters set of wires to be connected to it, I am doing exactly what the definition as 366.2. as you pointed above,
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
I am connecting all the meters to a main disconnects (and then from each meters it'l go to disconnects for each bay), inside the main disconnect there is not enough room for the (6) meters set of wires to be connected to it, I am doing exactly what the definition as 366.2. as you pointed above,
The gutter is to make more room in the original enclosure. If you are adding the gutter and making enough room to land the six sets of wires within the disconnect itself, fine.

If you running one set of conductors out of the main disconnect and splicing to the other 6 sets of conductors in your "gutter", it is my opinion that you have a wireway or a junction box, and not a "gutter".
If I was the plan review, it still gets rejected.

Also what it the enclosure you are going to use listed as?
 
Location
Miami, FL
The gutter is to make more room in the original enclosure. If you are adding the gutter and making enough room to land the six sets of wires within the disconnect itself, fine.

If you running one set of conductors out of the main disconnect and splicing to the other 6 sets of conductors in your "gutter", it is my opinion that you have a wireway or a junction box, and not a "gutter".
If I was the plan review, it still gets rejected.

Also what it the enclosure you are going to use listed as?

Enclosure will be metal N3

My understanding of your point (correct me if I am wrong), is the if we need extra room to add an additional conduits and wires and do the taping at this connect it self it will be ok (then I see it as wireway or pull box) but if I do the taping at the additional enclosure then is a J-box and need to comply with 314.28

However in the 2008 NEC edition the definition of this enclosure was change removing the term "wireway" to be more specific. 366.56 (A) allow to do taping inside the auxiliary gutter and do not specific or limit the amount of taping. 366.58 (A) refer to the table 312.6(A) and in my case a 12x12 will be ok. If I do the tapping at the disconnect only then this "gutter" is used as a "pull box" and need to comply with the 366.58 (B) that make you to comply with 314.28 (A) 1 & 2.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
It is my opinion that where conductors enter and leave a wireway, then that wire way is being used as a pull box and the sizing rules in 314.28 apply. This is not a common reading of the code (and somewhat surprised that the plan reviewer has read it the way I do), but the issue is conductor damage when they are being installed. This damage typically happens when you are trying to force the end of the loop into the enclosure that is too small....that is one that does not comply with 314.28.

I have submitted a public input for the 2017 code on this issue. We will see what the CMP has to say.

So if the conduit enters a PB directly that makes the PB a pull box?
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
So if the conduit enters a PB directly that makes the PB a pull box?
It is a pull box if the conductors enter and leave the enclosure. If they are splice or terminated, I am not as sure, but 314.28 says the "6x" rule applies to boxes that contain conductors that are spliced.
The issue of conductor damage is what drives the rules in 314.28. In my opinion that same issue exists no matter what you call the enclosure.
 
Location
Miami, FL
It is my opinion that where conductors enter and leave a wireway, then that wire way is being used as a pull box and the sizing rules in 314.28 apply. This is not a common reading of the code (and somewhat surprised that the plan reviewer has read it the way I do), but the issue is conductor damage when they are being installed. This damage typically happens when you are trying to force the end of the loop into the enclosure that is too small....that is one that does not comply with 314.28.

I have submitted a public input for the 2017 code on this issue. We will see what the CMP has to say.

The plans got approved, and everything was resolved using the 366, the review was agree in all except we should use the 366.58(B), this is when the gutter is used as pull box, in my case is typical gutter next to the main disconnect (connected with nipples), and the wires for the meters passing through a nipple at the bottom of the gutter, (we agree the wires from the transformer up to the main, and from the load center up to each disconnect are pulled) however the wires passing through the nipple were not consider pulled and as per the definition 336.2 the enclosure is designed to for the conductor to be "laid in or set in place". There is another typical installation on services when the 366.58(B) need to be consider, when the wires come straight from the transformers and get into the bottom of the gutter itself and then tap into the conductor feeding the meters, in this case the wires were pulled up to the gutter, this is when 366.58(B) therefore 314.28 will apply; you can get into the gutter by the side with elbow, then even if the wires are pulled throughout the box the conductors will "laid in or set in place" therefore 366.58(B) will not apply. I am glad it was solved this way, there is to many gray areas on the code were the interpretation and respectfull discussion can find a safe common ground.
 
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