200 amp ats switch install with an existing 150amp panel.

[Tim11]

Hi everyone looking for a help and advice. This is probably a pretty common scenario in a dwelling but I work commercial and Industrial so wanted to run it by those of you who who would more familiar just in case I'm missing anything.

A friend of my family purchased a 22kw standby generac kit which came with a 200 amp service rated ATS. Anyways, I am curious if there any issues or violations with utilizing the 200 amp ats without having to upgrade his exsisting 150 amp panel?

His meter can and lateral are both rated for 200 amps. So as long as I upgraded his service entrance conductors to the utility side of the ATS with a 4/0 AL. Then sub fed his 150 amp main breaker panel with 4/0 AL or a 2/0 Cu plus a #6 equipment ground I don't think there would be any issues besides changing his cold water bond to a #4 cu.

Would appreciate any input and or advice...

 

[augie47]

I see no problem.
If one of the 240.21 tap rules apply you could possibly get by with a smaller feeder.

 

[Tim11]

That's a good point.

I was planning on placing the ATS on the inside of the home directly next to exsisting service panel. He doesn't have much room to work with on the exterior of the home next to the meter. You could make it work but it would look goofy.

 

[Tim11]

I see no problem.
If one of the 240.21 tap rules apply you could possibly get by with a smaller feeder.

Not all too familiar with the 10ft tap rule haha. Just looked at my 2017 code book and I believe the smallest feeder in that case would be a 1/0 Cu for a 150amp ocpd as long as all other requirements are meant.

1/0 Cu at is rated for exactly 150 Amps at 75 degrees C and nothing for AL.