Properly configuring layout for 400 A service/meter socket with 3 downstream panels

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gcammerata

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This is my first post on this forum. As a quick overview, I have a large shop/equipment building that is adjacent to where my new home will be constructed. The equipment building is complete, the home won't break ground until next year. The new pad mount utility transformer is adjacent to the new equipment building. The service size is 400A. Ultimately, I want the shop to have a 150A load center (sub panel), and the main house to have two, 200 A load center (sub panels). Inside the equipment building, immediately after the meter socket, I am assuming would need a 400A fused disconnect, followed by a 600A trough that would allow me to connect each of the 3 sub panels. Here are my questions:

1. Is this the best way to do this or is there a better way?

2. Is the 400A fused disconnect better than a 400A breaker in an enclosure?

3. I have never used a trough, but if that is the best way to go, the ones I have seen have bus bars inside. How do I make the connections to the bus bars.

4. Any links to specific equipment would also be helpful.

Thank you for the help!

Greg
 
Since you will have only 3 throws of a hand (you're allowed 6) I would think about a 400 amp main lug panel with (2) 200 amp breakers and (1) 150 amp breaker. (Since this will probably be on the other side of the wall from the meter it may not be legal) I'm sure someone will tell me if I'm wrong....
You'll probably be required to do a load Calc too.
 
qcroanoke said:
Since you will have only 3 throws of a hand (you're allowed 6) I would think about a 400 amp main lug panel with (2) 200 amp breakers and (1) 150 amp breaker. (Since this will probably be on the other side of the wall from the meter it may not be legal) I'm sure someone will tell me if I'm wrong....
You'll probably be required to do a load Calc too.
Click to expand...
Can’t do that anymore, each service disconnect has to be in its own enclosure now.
 
gcammerata said:
This is my first post on this forum. As a quick overview, I have a large shop/equipment building that is adjacent to where my new home will be constructed. The equipment building is complete, the home won't break ground until next year. The new pad mount utility transformer is adjacent to the new equipment building. The service size is 400A. Ultimately, I want the shop to have a 150A load center (sub panel), and the main house to have two, 200 A load center (sub panels). Inside the equipment building, immediately after the meter socket, I am assuming would need a 400A fused disconnect, followed by a 600A trough that would allow me to connect each of the 3 sub panels. Here are my questions:

1. Is this the best way to do this or is there a better way?

2. Is the 400A fused disconnect better than a 400A breaker in an enclosure?

3. I have never used a trough, but if that is the best way to go, the ones I have seen have bus bars inside. How do I make the connections to the bus bars.

4. Any links to specific equipment would also be helpful.

Thank you for the help!

Greg
Click to expand...
The fused disconnect may be easier to get right now. Breakers seem to have a long lead time.
 
Do you have any idea which Code cycle will be in effect when you do the installation.
The "six throw disconnect rule" and the number of feeders you can install to the house both change between the 2017 and 2020 Code cycles.
 
augie47 said:
Do you have any idea which Code cycle will be in effect when you do the installation.
The "six throw disconnect rule" and the number of feeders you can install to the house both change between the 2017 and 2020 Code cycles.
Click to expand...
Hi Augie , Yes the installation will be done within the next 30 days, so it appears 2017 NEC will apply
 
Thanks for the replies so far everyone. If I choose to meet the newest version of the code, even though PA is still on 2017 NEC, it would mean the two 200 A sub panels in the main house would each have 200 A main breakers, and the 150 A sub panel in the equipment building would also have a main breaker, correct?
If I use a 400 A fusible disconnect immediately on the interior wall from the 400 A meter socket, what is the best way to get from the fusible disconnect to the 3 feeds, one for each sub panel? Do I need a trough?
 
gcammerata said:
So would it make sense to go from the fused disconnect to a trough to pull the other feeds from or is there a better way?
Click to expand...
Lugs for all 3 feeders on the load side of switch? Not sure how tap rule would play into this.
 
We would install like this................
Place meter base, if the panels are opposite the meter base, nipple through to one panel, and LB, sweep, etc. over to other panel. At one of the panels, use a feed through block to feed the 3rd panel. No outside disconnect needed as we are still on the 2017.

If the panels aren't close, then two disconnects to two panels and feed out of one panel to the 3rd panel.

This is assuming a 320A (400) meter base.
 
Under the 2107 Code you are not allowed 2 feeders (just pointed out by curt)...
It's a bit "backward" but I would ask my AHJ if I could apply 230.40 Exception3 and feed the house directly off the 400 amp meter
(norm would be the meter on the house then a feed to the shop) and install a small wireway at the house to feed yopur two panels with that service sized by Art 220.
 
augie47 said:
Under the 2107 Code you are not allowed 2 feeders (just pointed out by curt)...
It's a bit "backward" but I would ask my AHJ if I could apply 230.40 Exception3 and feed the house directly off the 400 amp meter
(norm would be the meter on the house then a feed to the shop) and install a small wireway at the house to feed yopur two panels with that service size
Click to expand...
 
Based on your reply, would this be an acceptable way to accomplish this within code rules (See attachement)
 

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gcammerata said:
Based on your reply, would this be an acceptable way to accomplish this within code rules (See attachement)
Click to expand...
It would be acceptable but likely a bit overkill. I would clear it with your AHJ but here you could come directly off your meter to the house (remaining outside)....if you do want to to go thru a disconnect I would calculate the load and see if a full 400 is needed
 
Little Bill said:
We would install like this................
Place meter base, if the panels are opposite the meter base, nipple through to one panel, and LB, sweep, etc. over to other panel. At one of the panels, use a feed through block to feed the 3rd panel. No outside disconnect needed as we are still on the 2017.

If the panels aren't close, then two disconnects to two panels and feed out of one panel to the 3rd panel.

This is assuming a 320A (400) meter base.
Click to expand...
Hi Bill, thank you for the feedback. Can you give me your thoughts on the attached configuration?
augie47 said:
It would be acceptable but likely a bit overkill. I would clear it with your AHJ but here you could come directly off your meter to the house (remaining outside)....if you do want to to go thru a disconnect I would calculate the load and see if a full 400 is needed
Click to expand...

augie47 said:
It would be acceptable but likely a bit overkill. I would clear it with your AHJ but here you could come directly off your meter to the house (remaining outside)....if you do want to to go thru a disconnect I would calculate the load and see if a full 400 is needed
Click to expand...
If I do it that way, and clear it with AHJ, I have 2 questions:

1. The load side of the meter socket would have to be capable of accepting 2 wires on each terminal, correct?
2. I would need to have 2 disconnects doing it this way (one at the house, and one at the equipment building), correct? How would I size those two disconnects? Because I thought there had to be one disconnect that matched the service entrance size (400A), that could turn off the entire service with one throw?
 

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  • Wiring.pdf
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Your meter socket would have 2 conductors per phase...normally not a problem as most have bolt on lugs.
You are allowed up to six disconnects at each location so one in your shop building and one or more at the house.
If you have two or more disconnects at the house the service conductors can be sized by the calculatedd load to a wireway (see Ex 3 to 230.90) where you would tap off with conductors rated for the individual panel mains
 
Thank you for your reply, I think I understand everything you described. The one thing that doesn't make sense is that you could technically be pulling more than 400A through the 400A meter/service if you do it that way. Because I would assume that the disconnect at the house would be 400A to accomodate the two 200A panels, and then you would have a disconnect at the shop of 150A. so if you are pulling maximum through each, it could, in theory be 550A before it trips. If you do it the other way, where there is a 400A main disconnect, wouldn't that protect the meter socket so that it never sees more than 400A? I am sure you are correct since you have alot more experience than me, its more that I don't understand why you would be allowed to pull 550A through a 400A service and meter socket.
 
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