Underground service design q

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I am looking at a job and was hoping I might be able to get a bit of advice to see if I'm on the right track.

The project is about a 7000 sf home. There is a transformer with meter pedestal about 250' away. The meter pedestal (provided by the utility) has (2) 200A breakers. There is currently (1) 3" Sch 40 PVC between the transformer and the homesite.

I was looking at pulling (6) 4/0 Cu THHN and (2) #4 Cu THHN in the 3". My question is what happens when we reach the house. Is there a cabinet that I can bring a 3" into that has (2) 200 breakers that I can terminate in? I've seen meter/ mains in that configuration but have never needed one with just breakers and no meter.

Also in this configuration do think it would be permissable to use SER from this cabinet to the panels in the house? Would this be considered service equipment since there is a disco in front of it? If not what wiring method would you recommed?

Thanks
 

Rewire

Senior Member
I am looking at a job and was hoping I might be able to get a bit of advice to see if I'm on the right track.

The project is about a 7000 sf home. There is a transformer with meter pedestal about 250' away. The meter pedestal (provided by the utility) has (2) 200A breakers. There is currently (1) 3" Sch 40 PVC between the transformer and the homesite.

I was looking at pulling (6) 4/0 Cu THHN and (2) #4 Cu THHN in the 3". My question is what happens when we reach the house. Is there a cabinet that I can bring a 3" into that has (2) 200 breakers that I can terminate in? I've seen meter/ mains in that configuration but have never needed one with just breakers and no meter.

Also in this configuration do think it would be permissable to use SER from this cabinet to the panels in the house? Would this be considered service equipment since there is a disco in front of it? If not what wiring method would you recommed?

Thanks
Why are you adding additional breakers outside?
 

Riograndeelectric

Senior Member
although I have worked any thing bigger than 200A feeds from a pedestal Meter before my guess would to bring the 3" into a gutter and then nipple out of the gutter to each panel.
I believe Square D makes a panel that would accommodate 2-200A breakers. But then since each of the 200A feeds are from seperate load then the could not pass thru the panel


I worked on a couple duplex house several years ago in commerce city. there was something strange about the property line in that Excel energy would provide 1 feed to each duplex we than had to set a gutter and than make tap of excel feeders to feed each of the 150A services .:)
 

Steviechia2

Senior Member
Location
Massachusetts
The 2-200 amp breakers are for the power company.They are a hot sequence for the power company to kill the load for them to work on the meter. Just bring the 3" to a gutter/trough and nipple into 2-200 amp main breaker panels. Treat this like a regular service- bonding is done inside to the panels not at meter. You could also run 2-2" and go directly to each panel and eliminate gutter.
 
Thanks for the input. The HO on this kind of went off half cocked and decided he wanted to get a trench dug and conduit in the ground before he consulted anyone on what should be in there- hence the 3". Given the opportunity to design it I would have opted for 2 2".

I was looking for one cabinet but I now think hitting a gutter and going into 2 separate discos is the way to go.

From that point is it permissable to use SER?
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
From your disconnects at the house (outside or closet point of entry), SER would be permissible if conditions allow.
Care should be taken on two accounts. As neither SER carries the entire dwelling load, 310.15(B)(6) is normally not allowed and, if you are under the '08 Code your AHJ may enforce the 60? ampacity rating per 338.10.
 

growler

Senior Member
Location
Atlanta,GA
I was looking at pulling (6) 4/0 Cu THHN and (2) #4 Cu THHN in the 3". My question is what happens when we reach the house. Is there a cabinet that I can bring a 3" into that has (2) 200 breakers that I can terminate in? I've seen meter/ mains in that configuration but have never needed one with just breakers and no meter.


It really doesn't matter where the meter is located. What really counts is where the main disconnect is located. If you are building the main at the house then I don's see the need to run a ground in the conduit.( I could be wrong !!!):mad:

I haven't seen this set up for residential so I would get with the power company engineer that is in charge of the project and with the local inspector and make sure what you are planning to do is going to be OK with them.
 
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