Wireway/Gutter Sizing

[hoffyone]

Need help sizing a gutter/wireway for building service with the following:
1 - 1600 amp main disconnect with 4 parallel runs of 4# 600 MCM and 1 # 4/0 THHN CU conductors in 3.5" conduit. Conduits will leave top of disconnect and enter bottom of gutter. Gutter/wireway will then extend over four 200-amp unit meters and two 400-amp unit meters. Length is no problem to figure, but what width and depth is required? Engineer has the notoriuos "Sized per NEC" note for this gutter/wireway.
Thanks,

 

[lowryder88h]

Wireway

Wireway

See NEC 376.21 & 376.22

 

[hoffyone]

Wireway

Wireway

Thanks, but should the width and height of the gutter be sized according to 314?

 

[lowryder88h]

Wireway

Wireway

Thanks, but should the width and height of the gutter be sized according to 314?

314 outlets,device, pull, and junction boxes; conduit bodies; fittings; and handhole enclosures. No mention of wireway that I can see. Unless I'm missing somethig.

 

[cadpoint]

Its two words

Its two words

the notoriuos "Sized per NEC" note for this gutter/wireway

Its two words and two different articles, gutters 366,
metal wireways 376, it for you to decide per the application.
Choose A or B and proof, AKA CYA...

 

[Joe Villani]

Wireway/ Gutter Sizing

Wireway/ Gutter Sizing

This is what I came up with.

I am assuming 4- 3/0 THHN conductors to each 200 amp meter pan

I am assuming 4- 500 KCMIL THHN conductors to each 400 amp meter pan/ ct cabinet.

16 600 kcmil .8676 square inches = 13.88 sq in.
4 4/0 .3237 square inches = 1.29 sq in.
16 3/0 .2679 square inches = 4.29 sq in.
8 500 kcmil .7073 square inches = 5.66 sq in.

Total square inches equals 25.12 square inches.

25.12 divided by 20 percent fill = 125.6 square inches.

A 12 by 12 wireway/ gutter has 144 square inches

NOTE: I did not include a grounding conductor to the meter banks. If you do remember 250.122 (G) and base it on the overcurrent device ahead of the feeder but shall not be required to be larger than the tap conductors.

Also remember with a 12 inch wireway/ gutter you will have to bring the metering equipment out of the wall to comply with 110.26 (A) (3).

Hope this helps

Joe Villani

 

[hardworkingstiff]

Depends

Depends

If your service disconnect is on one end of the run, then I believe you can get by with a smaller square inch calculation. The 4 sets of 600 will encounter the 1st service, and you should only need to size the wireway for the 600's and one set for the service (since the rest of the services will be farther down the wireway and the 1st set of service conductors won't be there), etc. etc.

 

[ryan_618]

You will have to use the "One conductor per terminal" value in Table 312.6(A). This is referred to somewhere in 376. 376.22? 376.23?

 

[chris kennedy]

Here's one I'm working on now. The gutter is installed. It is 12"X12"X72".I have 7 entries that are 4" with 4 500's and 1 3/0. Calc is 110 sq". Fine. Now try and cram the wire plus 4 polaris for 8 500's in there. Each entry in the polaris must take up about an inch. 4 8" polaris in 12x12 gutter. I'm going to look like the where's Waldo post when it comes time to terminate that one. I'll let you know about bending radius later.

 

[Dave_PE]

Need help sizing a gutter/wireway for building service with the following:
1 - 1600 amp main disconnect with 4 parallel runs of 4# 600 MCM and 1 # 4/0 THHN CU conductors in 3.5" conduit. Conduits will leave top of disconnect and enter bottom of gutter. Gutter/wireway will then extend over four 200-amp unit meters and two 400-amp unit meters. Length is no problem to figure, but what width and depth is required? Engineer has the notoriuos "Sized per NEC" note for this gutter/wireway.
Thanks,

Why not use a 1600A metercenter?

 

[e57]

Why not use a 1600A metercenter?

Maybe due to depth? 1600a ends up being a cabinet main section, where as a 6-10" gutter over 6-10" equipment might be better suited to the space. Otherwise I agree, some bolt together buss equipment slapped on the wall sounds like much less time.