Advice: Customer wants a 400a ATS and Gen to power entire house

[gooblanzee]

As stated in title...
Customer wants a 400a transfer switch installed for a FUTURE ~400a genny to power his entire home.
Does not want the genny installed, just pre-wired with an ATS, gen feed, etc.

New construction home.
400a service
3x 200a sub panels
(upstairs, downstairs, A/Cs + outdoor equipment)
Single phase

Planning on installing a 400a ATS next to the 400a meter base.
Feeding a 400a Nema 3r Main breaker load center
Part #- BR4242B400R
Then branch off to feed the 3 Subs with 200a breakers

That's where what I thought was a good plan dissolved. I cannot find plug on 200a BR breakers for the 400a main panel


PHOTO OF MOCK UP

Anyone have some advice on this?

https://imgur.com/a/PLyaCIs

 

[ptonsparky]

Use the tap rules.

 

[gooblanzee]

Use the tap rules.

The ATS does not have lugs for parallel taps on the load side. At least, none I have found thus far do. Where would I make my taps?

 

[hillbilly1]

As ptonsparky suggested, just use two 200 amp 3r mains tapped off the 400 amp tswitch. If the load lugs on the switch do not accept two wires if single lug, or does not have double lugs, use insulated tap blocks such as made by Polaris to split off the full size 400 amp feed.

 

[gooblanzee]

As ptonsparky suggested, just use two 200 amp 3r mains tapped off the 400 amp tswitch. If the load lugs on the switch do not accept two wires if single lug, or does not have double lugs, use insulated tap blocks such as made by Polaris to split off the full size 400 amp feed.

Thank you.

Will reduce down to 2x 200a mains.

I was complicating it by trying to tap off with 3x 200a panels.

got it

 

[hillbilly1]

Just seen you are feeding four 200 amp subs, still can be done with three 200 amp 3r disconnects with one 200 amp MB 3r panel for the A/C’s. Five port Polaris lugs and a 3r wireway would be a must. The 400 amp tswitch is service rated?

 

[hillbilly1]

Manufacturer of Aluminum and Copper set screw connectors for the Utility, OEM, and Contractor and Industrial Markets

There are other manufactures of the same style.

 

[mopowr steve]

The ATS does not have lugs for parallel taps on the load side. At least, none I have found thus far do. Where would I make my taps?

The last 400 A Generac ATS I installed did have its lugs rated for parallel conductors. They are single lug but of an oblong hole design for installation of two conductors.

 

[electrofelon]

Just seen you are feeding four 200 amp subs, still can be done with three 200 amp 3r disconnects with one 200 amp MB 3r panel for the A/C’s. Five port Polaris lugs and a 3r wireway would be a must. The 400 amp tswitch is service rated?

Perhaps getting a nice single panelboard, with the 200A breakers and the AC stuff in it as well would be the way to go.

 

[gooblanzee]

Perhaps getting a nice single panelboard, with the 200A breakers and the AC stuff in it as well would be the way to go.

I cannot find a 400a 240/120V single phase Nema 3r panel with bolt breakers or even snap in breakers that size to 200a. Any suggestions?

 

[gooblanzee]

The last 400 A Generac ATS I installed did have its lugs rated for parallel conductors. They are single lug but of an oblong hole design for installation of two conductors.

Was that the #RXSW400A3? Generac Listing

 

[electrofelon]

I cannot find a 400a 240/120V single phase Nema 3r panel with bolt breakers or even snap in breakers that size to 200a. Any suggestions?

A Siemens P2 panelboard would do it. You would have to order it from Siemens. Just tell them what you need and it shall be done

 

[hillbilly1]

Perhaps getting a nice single panelboard, with the 200A breakers and the AC stuff in it as well would be the way to go.

Yes, the op could get a Square D iLine panel, it would be a little more pricey, but would be a cleaner look.

 

[electrofelon]

Yes, the op could get a Square D iLine panel, it would be a little more pricey, but would be a cleaner look.

yeah that would work too. Only thing with an I-line is Im not sure if you can put 15-100A miniatures in there in addition to the distribution breakers. I know the Siemens can be configured with a mix of different frame sized breakers if you wanted/needed.

 

[hillbilly1]

yeah that would work too. Only thing with an I-line is Im not sure if you can put 15-100A miniatures in there in addition to the distribution breakers. I know the Siemens can be configured with a mix of different frame sized breakers if you wanted/needed.

You can, my old boss has a 600 amp in his house, and it has an adapter for QO breakers. His is five + years old, so they should still have them readily available. He also has three 200’s feeding panels throughout the house.

 

[paulengr]

yeah that would work too. Only thing with an I-line is Im not sure if you can put 15-100A miniatures in there in addition to the distribution breakers. I know the Siemens can be configured with a mix of different frame sized breakers if you wanted/needed.

The older ones are limited to 150 A frames. The newer “F” series frames if I remember my numbering go up to 250 A in Square D.

With Siemens you may have to upgrade to the larger 800 panel board but it will do it. Common for mobile home parks.

 

[electrofelon]

.

With Siemens you may have to upgrade to the larger 800 panel board but it will do it. Common for mobile home parks.

Yeah the Siemens P1 can only take B and BQD branches (15-125A). Move up to a P2, which is a 600A panelboard, and you can do QR frame branches which go up to 250A.

 

[gooblanzee]

Yeah the Siemens P1 can only take B and BQD branches (15-125A). Move up to a P2, which is a 600A panelboard, and you can do QR frame branches which go up to 250A.

Sounds like the P2 is what I am after. Thank you guys for all the help.

 

[augie47]

side note: Check your equipment ground size for your 400 amp ATS.

 

[mopowr steve]

Was that the #RXSW400A3? Generac Listing

Looks right, even though the listing shown says lug size for 600-#4 or 1/0-250 this must be a typo should say (2) 1/0-250. I’m sure that I checked this during the install if not printed on the lug then it must have been in the spec sheet.