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#34310 02/08/04 01:56 PM
Joined: May 2001
Posts: 129
frodo Offline OP
I am wondering about your advice on the following installation:

Need to upgrade an existing 125A service to 200A and install new 200A load center in basement. There is an existing 125A loadcenter w/main that will be left in service.

I am proposing the following installation:

Install a new meter base on exterior wall of garage, immediately on the inside there will be a main breaker. From there I plan to install a SE Cable down to the basement to a gutter then refeed the existing 125A panel and the new 200A panel. Do I need a main in the 200A panel?

Or, should I feed the 200A panel from the main then refeed the 125A panel from the 200A panel?

Thanks for any ideas or comments.


#34311 02/09/04 01:41 AM
Joined: Sep 2003
Posts: 200
Sounds similar to my situation...

- existing 100A SE panel in house
- existing 60A sub-panel for basement suite
- existing 40A sub-panel in attached garage
- going to install new 200A service in attached garage
- going to install a sub-panel in detached garage

I've found that standard 100A and 200A panels (with main breaker) are very cheap because of the market demand. OTOH, a 200A enclosed switch, splitter/gutter, and a 200A load center (no main breaker) are going to be spendy.

I'll be installing the 200A SE panel in garage, then feed the house, suite, attached garage, and detached garage from it.

The only situation I see where the main switch is desirable is if all your loads are closer to the existing 125A panel than they are to the new SE. Even then, I think I'd scrap the gutter idea, and feed the 125A as a branch circuit in the new 200A panel. Heck, if you keep with the same brand panels, there's a chance you can convert your 125A panel to main lugs and re-use the 125A breaker in the 200A panel.

I've intentionally not gone into Code details as the NEC applies to you, and the CEC applies to me. [Linked Image]

#34312 02/09/04 06:06 AM
Joined: Jul 2002
Posts: 8,423
Likes: 3
Not sure what normally happens in the US, but here in NZ, we would feed the SE to the 200A panel and run a Submain to the 125A panel.
Main Isolator would be in the 200A panel.
Also don't get me wrong, we don't use services this big in a house here, we use 230VAC 2 Wire, as standard!. [Linked Image]

#34313 02/09/04 10:47 PM
Joined: Jan 2004
Posts: 615

I'm not entirely familiar with the use of SE cable because I don't use it up here in IL. But if you put a main breaker immediately after the meter, then technically your run down to the basement would be a feeder and not service entrance. Can you use SE cable for anything outher than Service Entrance? (sorry I'm not familiar with it.)

A couple of different ways to consider doing it, all would depend on different variables.

Could you change the 125 amp panel to the 200 amp and then feed off that to a 100 amp in the basement?

Could you put the 200 amp meter on a wall just outside the basement and put the 200 amp there, and then feed th garage with 100 amp?

Get a combination meter with two breakers (this would technically be called the service, so pay attention to how you ground and bond) and feed each with its own breaker? (2) 100 amp breakers..... or a 300 amp service with (1) 100 amp breaker and (1) 200 amp breaker.

I don't have the NEC reference, but you can't put a breaker in a panel that is larger than half the size of the main. (somebody please correct me if I'm wrong)

Good luck.

#34314 02/10/04 12:13 AM
Joined: May 2001
Posts: 129
frodo Offline OP
se cable is used frequently to feed new or existing sub panels in residential or commercial applications like aprtment complexes. you can not get away with running it unprotected from the meter base to the main, but from the load side of the the main there is no restriction on using it that I am aware of.

Also, I am not aware of any problem feeding a 125 amp panel from a 200A main lug panel. It is all dependant on the load being served.

My main consideration is the size of the main and the ampere rating of the meterbase..I am not familiar with any residential meterbases that are larger than 200A.

I will have to do some research to see what the actual calculation is to determine exactly what the code says about sizing breakers for this type of situation.

I was sure that this is not a unique situation and that someone else has already been down that road. If you are dooing a large home a single 40 ckt panel is not going to be large enough to handle all the circuits, so usually two load centers are installed side by side...i am just curious as to the size of the main etc..

I have seen plenty of 200A panels with 100 & 125A breakers in them!

thanks for any ideas/comments.

I will dig into it and see what the good book says.



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