Hi all!

Please bear with me as this could be long. I want to get all the details here.

I have asked a few questions here regarding this same setup and have come a long way with it. I just kind of want to bounce this off you again to make sure it is good to go as well as I have a few other questions.


First, the background:

400 Amp service to my new home. (Not a 320, a true 400AMP K-Can provided by the POCO.)

My plans are to split the service at the meter to 2 200 amp feed through main breaker outdoor panels. (Square D QO1816M200FTRB) (This is to fulfill the disconnect grouping requirement of the NEC.)

Click here to see a drawing of the setup


Service Panel A: Using the Feed through lugs, I will wire to the 200 AMP Siemens indoor main breaker panel located back to back with Service Panel A and will connect with a 2 1/2 inch close nipple. This will be the house's main distribution panel.

Service Panel B: Using the feed through lugs, I will wire to the 200 AMP Siemens indoor main breaker panel located in my detached garage approx 100-120 feet away. (Not physically, rather linear distance of the feed.) This will be the garages main distribution panel which will likely feed an addition subpanel in the future.


Now, we like to do HUGE Christmas light displays, so the electrical system has been mostly designed around that. (And is also the reason the POCO engineer approved us for a true 400Amp service.) We are looking at about 19 outdoor electrical receptacles. (These will be spread across about 10 circuits.) So what I want to do is feed these from Service Panel B. (This will allow my huge light display to draw from my garage feed and not affect my house. My lights would dim at the old house and I could not use other high draw appliances with the lights on. :eek: I will not likely be working in my garage while the light display is on.) My initial plan was to feed them directly from Service Panel B, however I realized there would be an issue with physically running the cables. SO... I have now planned to install a second panel in the house next to the primary panel. This is an identical panel as the first (a 200AMP Main Breaker Siemens.) This would be fed from a breaker in Service Panel B as a subpanel. (I have yet to locate the stab rating on the Square D box, so I am not sure what breaker I will use yet.)

So after all of that, here are my questions:

1. Does this plan seem OK? (I mean from a crazy, way more amperage than the average person needs, point of view.)


2. I am a big fan of copper wire, however with prices the way they are I am considering Aluminum. Will mobile home feeder be acceptable to run to the detached garage (100-120ft) and is it direct burial? (I would love to not have to run conduit due to the four 90 degree bend rule.)


3. What size wire would you recommend for the 200AMP service to the garage? (I have an idea, but would still like more input, mainly in AL. Again, I love copper.)


4. I am thinking I will use SEC to feed from Service Panel B to the subpanel inside the house. It will need to run into the house through the wall, up through the top plate, over about 4 or 5 feet, then down into the panel. My thought is to use a watertight entrance connector out of the back of Service Panel B (with the rubber side poking into the interior wall cavity.) Then run the SEC to the panel with a standard SEC cable clamp on the top of the panel. Is this the proper way to do this? I am assuming that the SEC needs to be clamped on each end which is why my thoughts go this way.


5. Is it acceptable to have this subpanel that is used to only feed exterior receptacles?


6. As a non-related to the above question, I have a mental block with the calculations for conduit fill. I have a 1" schedule 80 PVC pipe that runs under my slab from my kitchen wall to the kitchen island. I know that I need to use UF cable, but my question is, can I run 2 12/2 UF cables in the 1" pipe without being overfilled? I realize in hindsight that I should have put in larger pipe.


I think that is all of my questions for now. (I know this is a lot, but inquiring minds want to know.)

A little background on me: I am building my own house, physically. I work alone 99.9% of the time. I have an uncanny ability to read and retain things. I have read the entire NEC 2005 handbook cover to cover. (Riveting read. LOL!) I am obviously not licensed and am considered a DIYer, however, I personally do not feel I am on the typical DIYer level.

I hope that I did not miss anything, but if I did, please ask.


Thank you again to all of the experts here.

A couple of comments: See the SE stuff at Midwest Electric Products, Inc.. It would make your life so much simpler. I think they have a 400 amp service that breaks down into two 200 amp breakers outside.

(5) My cousin did the same thing. Had about 100,000 xmas lights on his house. I might use a main breaker in this panel just to serve as a disconnect. That breaker could be 200A and the feed be 100 Amps and still be a 100 A panel.

Thanks KISS.

The meter housing and dual Square D panels are already purchased and setup for the house. The POCO gave me the meter can so that saved me a boat load of cash and allowed me to go the full 400 amp service. They even installed the double lugs for me so I was good to go. I got the Square D panels on clearance. I can't remember what I paid, but I think I got 2 for the price of one. I will still look at the site you posted for the knowledge. I can't seem to get enough of it into my brain. :)


All of the panels I have are main breaker. I thought the same thing about the main being a quick switch to kill all the lights at the end of the night.

(You know, with the newer LED Christmas lights, 100,000 lights is like 3amps. LOL!)