Now I want a generator - Wireway Sizing

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SIRSPARKSALOT

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Saturday before Sandy I began installing a 400A residential service for my customer. Everything was great...then Sandy hit. Now the customer wants a stand-by generator. Is my trough (6x6) big enough for the feeders to pass straight through to get to the ATS and receive and tap the feeders coming from the ATS? Please see the picture.

If I knew there was a generator being included in the design, my approach to the service would have been much different. Now I deal with it and move forward.

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First, I have to agree with Bob. NEC 702.5 requires your generator match your calculated load. Once you have decided how you are to accomplish that, it might be easier to address the layout.
Keep i n mind that service conductors and non-service conductors can not occupy the same raceway although a barrier might address that problem.
 
1. Calculated load is 33,230VA
2. Customer wanted a 400A service from POCO because bigger is better...I tried to tell him.
3. Customer wants all of the house on the generator (ie. general lighting, heat, etc.)
4. If I load shed the A/C units using the LCM modules it brings the load down to approximately 18,000VA. Probably going to go with a 30kW anyway.

The reason for the 400 Amp transfer switch is to use as the 400A main.

The reason for the fused switches was to comply with 310.15(B)6 as the subpanels are fed with SER cable.

I forgot about occupying the same raceway...thanks Augie!

Any other thoughts?
 
Always difficult top second-guess not being in site, but my thinking would be to feed the ATS by a nipple between the meter and the ATS and convert the wireway to feeders from the ATS to the disconnects using the tap rule, either by feeders to the ATS, length permitting or taps in the wireway.
 
My thought was to bring the 400A feeder from the ATS to the wireway and tap there to feed each 200A disconnect.

I am seeing manufacturer of the wireway I installed has a listed barrier to deal with the service entrance and non service entrance conductors in the same raceway.

Thanks for the input Augie!


Sandy has fouled up a bunch of things up here including this. I need to foul up in reverse now.:)
 
what are the two 200A disconnects for? two downstream panelboards?

can you make the xfer switch fused and make it the service disconnect? then you would not need to worry about the service wires in the raceway issue although I am inclined to agree that a short conduit run from the meter to the ATS would simplify things a lot.
 
petersonra said:
what are the two 200A disconnects for? two downstream panelboards?

can you make the xfer switch fused and make it the service disconnect? then you would not need to worry about the service wires in the raceway issue although I am inclined to agree that a short conduit run from the meter to the ATS would simplify things a lot.
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Yes. The original design was to have (2) 200A panels. One would be flush mounted in the garage and the other placed in the basement. Additionally, the garage panel would take care of the garage, a 100A subpanel on the second floor and site power (over 4 acre lot). The outside fused switches allow me to use SER cabling to feed the other sub panels while having the ability to fuse the feeders down in order to comply with 310.15(B)6.

Now...it's built and I am looking for the most cost effective way to incorporate the generator.

POCO will not allow me to nipple out of the left side of the meter base as they claim that if for their wiring only and I cannot cross their wiring. So...I can either move the meter to the left (not looking to do that) or provide a barrier (thanks Augie) and head U/G to the transfer switch and back to the trough.
 
Eliminate the wireway and run one conduit fron the meter socket to the ATS.
Then run individule conduits from the ATS to each disconnect.
Install double lugs on the load side of the ATS and then you are code complient.
 
Was that wireway ever large enough? How are you getting 6X to the opposite wall from the nipples below the panel? What pathway are you taking into the wireway from the ATS -- below or the side? With a U pull and 1.5" conduits, you'd need 9" to the opposite wall. With 2" conduits, you'd need 12" to the opposite wall. Actually probably even more than this since you have multiple conduits in a given wall.
 
suemarkp said:
Was that wireway ever large enough? How are you getting 6X to the opposite wall from the nipples below the panel? What pathway are you taking into the wireway from the ATS -- below or the side? With a U pull and 1.5" conduits, you'd need 9" to the opposite wall. With 2" conduits, you'd need 12" to the opposite wall. Actually probably even more than this since you have multiple conduits in a given wall.
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So which article applies here...314 or 376?
 
May not be practical but what if you moved the meter to the left where you were originally going to put the transfer switch and put the transfer switch in the spot where the meter is now?

It would lay out just right.


Just a thought.
 
jap said:
May not be practical but what if you moved the meter to the left where you were originally going to put the transfer switch and put the transfer switch in the spot where the meter is now?

It would lay out just right.


Just a thought.
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He has indicated he doesn't want to do that, but I still think it is best thing to do. Hopefully the backhoe in the photo is still available
 
SIRSPARKSALOT said:
So which article applies here...314 or 376?
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Actually Aux gutters is Art 366. 366.58 does have references to 312.6(A) and 314.28(A), use whichever one applies. I believe the 312.6(A) dimensions apply to this installation, and the 6 inch gutter is likely fine if no conductors are larger than 250 kcmil.
 
suemarkp said:
Was that wireway ever large enough? How are you getting 6X to the opposite wall from the nipples below the panel? What pathway are you taking into the wireway from the ATS -- below or the side? With a U pull and 1.5" conduits, you'd need 9" to the opposite wall. With 2" conduits, you'd need 12" to the opposite wall. Actually probably even more than this since you have multiple conduits in a given wall.
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The dimensions to the opposite wall are not required for auxillary gutters and wireways used as pull boxes. Only the distance between raceways are required to meet the 6X or 8X rule.(376.23(B). The height of the wireway has to meet the deflection of conductors from table 312.6(A). See 376.23(A).
 
I would get a new gutter (8 X 8) and move it to the left. Pipe straight from the meter to the transfer switch thus eliminating the need for a barrier. Then from the transfer switch to the gutter and on to the disconnects.
 
masterinbama said:
I would get a new gutter (8 X 8) and move it to the left. Pipe straight from the meter to the transfer switch thus eliminating the need for a barrier. Then from the transfer switch to the gutter and on to the disconnects.
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OP stated the POCO claims the left side of the meter socket for their supply conductors and he can not nipple out of that side.
 
kwired said:
Actually Aux gutters is Art 366. 366.58 does have references to 312.6(A) and 314.28(A), use whichever one applies. I believe the 312.6(A) dimensions apply to this installation, and the 6 inch gutter is likely fine if no conductors are larger than 250 kcmil.
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kwired, did you use the second column of 312.6(a) for that figure? Meaning two conductors per termination and if so you chose that because the feeder conductor appears that it would have two taps coming off it?
 
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