wire ways or gutter fill ?

[wireman1]

what size wire way would you need for 70 number 12 thhn wires and must you derate after 30 wires can you put a barrier in the wire way to separate the conductors . also what is the difference between a wire way and a auxillarygutter

 

[infinity]

In the past it was my opinion that a barrier made the wireway (similar to a barrier in boxes) into two separate compartments, the CMP thinks otherwise.

8-134 Log #798 NEC-P08 Final Action: Reject
(376.22)
________________________________________________________________
Submitter: Paul E. Guidry, Fluor Enterprises, Inc. / Rep. Associated Builders
and Contractors
Recommendation: This is an updated proposal to one previously sent. Part of
the text was left out. Please reject the previous proposal.
Add new text to read:
376.22 Number of Conductors and Ampacity. The number of conductors and
their ampacity shall comply with 376.22(A) and (B).
(A) Cross-Sectional Areas of Wireway. The sum of the cross-sectional areas of
all contained conductors at any cross section of a wireway shall not exceed 20
percent of the interior cross-sectional area of the wireway.
(B) Adjustment Factors. The adjustment factors in 310.15(B)(3)(a) shall be
applied only where the number of current-carrying conductors, including
neutral conductors classified as current-carrying under the provisions of
310.15(B)(5), exceeds 30. Conductors for signaling circuits or controller
conductors between a motor and its starter and used only for starting duty shall
not be considered as current-carrying conductors.
For the purposes of this Section, wireways with metallic dividers installed
constitutes separate wireways.
Substantiation: Wireways are often being used with dividers that are a listed
part of the equipment. Often these divided sections contain up to 30 current-
carrying conductors in each divided section. Where dividers are used, this
proposal would allow each divided section of the wireway to be counted as
individual wireways and allow up to 30 current-carrying conductors and 20%
fill without derating of ampacities.
Panel Meeting Action: Reject
Panel Statement: CMP-8 acknowledges that the use of internal barriers in
wireway is not prohibited. The submitter has not provided adequate technical
substantiation to permit increasing the number of conductors in a divided metal
wireway above 30 without applying the provisions of Section 310.15(B)(5).
Number Eligible to Vote: 12
Ballot Results: Affirmative: 12

 

[dkidd]

As its name implies, an auxiliary gutter provides additional gutter space for wiring in various types of electrical enclosures and equipment. This additional gutter space may be necessary to provide sufficient room for the number of conductors in an enclosure or to provide adequate wiring bending/deflection space where conductors connect to a terminal. Although the construction of an auxiliary gutter is no different from that of a wireway, it is the field application of this equipment that differentiates an auxiliary gutter from a wireway.
A wireway is a raceway in accordance with the definition of raceway in Article 100. Auxiliary gutters supplement enclosure wiring spaces and are not encompassed by the definition of raceway. Therefore, Code requirements that apply only to raceways do not apply to auxiliary gutters. An example of such a requirement is 230.7, which prohibits service conductors from being installed in a raceway with conductors that are not service conductors. This rule applies to wireways installed in accordance with Article 376 and 378. However, an auxiliary gutter installed to supplement the wiring space of a service equipment enclosure is not a wireway and therefore is not subject to 230.7.
2011 Handbook

An auxiliary gutter provides additional gutter space for wiring in various types of electrical enclosures and equipment. This additional gutter space may be necessary to provide sufficient room for the number of conductors in an enclosure or to provide adequate wiring bending/deflection space where conductors connect to a terminal. Although the construction of an auxiliary gutter is no different from that of a wireway, the field application of this equipment differentiates an auxiliary gutter from a wireway.

A wireway is a raceway in accordance with the definition of raceway in Article 100. Auxiliary gutters supplement enclosure wiring spaces and are not encompassed by the definition of raceway. Therefore, Code requirements that apply only to raceways do not apply to auxiliary gutters. An example of such a requirement is 230.7, which prohibits service conductors from being installed in a raceway with conductors that are not service conductors. This rule applies to wireways installed in accordance with Article 376 and 378. However, an auxiliary gutter installed to supplement the wiring space of a service equipment enclosure is not a wireway and, therefore, is not subject to 230.7.

2014 Handbook

 

[Cow]

The best I've come up with now, is to make sure conductors come into the gutter as close to the panels or equipment as possible to stay under 30 ccc's. If that isn't possible, I'm willing to stack another gutter on top of an existing one and chase nipple between. With you having 70 conductors, it might look a little out of place having 3 gutters stacked though....?

 

[dkidd]

The best I've come up with now, is to make sure conductors come into the gutter as close to the panels or equipment as possible to stay under 30 ccc's. If that isn't possible, I'm willing to stack another gutter on top of an existing one and chase nipple between. With you having 70 conductors, it might look a little out of place having 3 gutters stacked though....?

You are talking about wireways, not gutters.

 

[infinity]

Auxillary Metallic Gutters have a similar 30 CCC limitation when applying adjustment factors. The 30 CCC limitation is for the entire gutter not just at a cross section.

366.23 Ampacity of Conductors.
(A) Sheet Metallic Auxiliary Gutters. Where the number
of current-carrying conductors contained in the sheet metallic
auxiliary gutter is 30 or less, the adjustment factors specified
in 310.15(B)(3)(a) shall not apply.