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-   -   400 amp service, 2 200 amp panels, 320 amp meter socket (https://www.askmehelpdesk.com/showthread.php?t=101878)

  • Jun 16, 2007, 09:56 PM
    GShelton
    400 amp service, 2 200 amp panels, 320 amp meter socket
    Hi, this is my first post here, but I have been reading a lot and have already learned a bunch.

    I want to thank TK already and hope you reply to this.

    I am in the process of designing my electrical system for my new home. I have some electrical experience, but am by no means a pro.

    I am putting in a 400 amp service. This will come in through a 320 amp meter socket. At that time I need to break it out to 2 200 amp panels. But this is where it is different than the others I have read about. One panel will be on the wall inside that backs up to the meter. The other will be about 120ft away in a detached garage.

    I am looking to split the incoming power in the meter housing. One side will run to the inside panel directly. (It will be equipped with a 200 amp main breaker.) The other side will run to a 200 amp panel or disconnect mounted outside next to the meter housing, then to the panel in the detached garage.

    Now I know that the panel in the detached garage will have to be wired as a sub-panel, but my first question is, when I split it at the meter housing does the panel in the house and the outside panel/disconnect get wired as a sub-panel or do they both get wired as primary panels. (One is not feeding the other, they are both fed from the meter.)

    Next question is, with a 200 amp panel in the house, a 200 amp panel outside the house (again, split in the meter socket, not in a panel) and the outside panel feeding a 200 amp panel in the detached garage, is it against code to then add any additional load to the outside panel that feeds the garage panel? (I hope this makes sense.) Let's say that I have the above situation and I decide to feed my well pump from the panel that feeds to the panel in the garage. I would then have a 200 amp breaker (2 pole) for the other panel and a 30 amp (2 pole) breaker for the well in a 200 amp panel. Is this against code?

    I know this is a lot to throw out here at once, but I appreciate all the help I can get.
  • Jun 17, 2007, 07:42 AM
    tkrussell
    Having a little trouble following your explanation.

    I am assuming the 320 amp meter will contain two 200 amp breakers. This will be considered as the Main Service Disconnecting Means. This is where the neutral, equipment ground, and grounding electrodes all connect, and only at this point. At any panel the neutral must be insulated and isolated from any equipment grounds. This is what is mistakenly understood by laypeople as a "subpanel".

    Any panel located in the garage must have at least one ground rod grounding the equipment ground bar, again, which does not connect to the neutral in this panel.

    First, there will be one panel just inside the home back to back of the meter, and the second 120 feet away in the detached garage.

    Then there is the inside panel, and a panel just outside, and then a panel in the garage.

    Really does not matter, any panel can feed any other panel, and the well pump, and comply with code. What needs to be considered is the load each panel will serve.
  • Jun 17, 2007, 11:00 AM
    GShelton
    So does the meter socket have to be a meter main in this situation?

    I was thinking I could use a twin lug on the output side of the meter and split to the inside panel (with a main) and the outside panel (with a main.)

    I was reading last night that the mains should all be in the same location though (I read that after I posted.) So that kills my theory.

    So I guess you have confirmed it all for me. I will need a meter main with 2 200 amp breakers.


    I would like to touch back on the 200 Amp panel feeding a sub-panel and the well. If the 200 amp panel is feeding through a 200 amp breaker to another 200 amp sub panel and I add the 30 amp breaker for the well, does that not put it at the possibility of drawing 230 amps per bus?

    I thank you again for your help.
  • Jun 18, 2007, 02:23 AM
    tkrussell
    Sure, if the load is that great. You need to know what the max load is before arranging breakers and panels.
  • Jun 2, 2008, 11:05 PM
    GShelton
    Hi TK,

    Sorry to drag this up from the dead, but after a long wait, I am finally installing my service.

    The POCO has approved me for a true 400amp service and supplied me with a K-Can (Landis and Gyr if it matters.) The meter can is just that. No mains. So here is my situation and what I want to do:

    The can has dual lugs already installed on the output. I want to come out of the can in 2 places. One will run to a 200Amp breaker (like a Cutler Hammer ECB200RB) and from there to the 200amp panel in the house. (Will be back to back.) This is strictly to have my main disconnect near the garage feed.

    The other out from the can, I want to run to a panel such as a CH CH8B200RF. This panel has 8 breaker locations and feed through lugs. I wish to run my outside receptacles from this panel. The feed through lugs will run to my detached garage where there is an additional 200Amp sub panel.

    So first question is: Will this work and is it acceptable?

    I understand that the panel in the house as well as the one in the garage have to be wired with 4 conductor and have the ground and neutral separate. So would the ECB200RB and CH8B200RF both be wired with a combined ground/neutral? If not, where would this occur?

    I know I will have more questions, but it is late and my head is spinning from all the reading I did tonight. LOL!

    Also, I like Siemens products, (I know some don't) but I could not find a panel with feed through made by them (or Murray). If you know of an option I would appreciate that knowledge also. I like to keep all my stuff brand specific. I know that doesn't really matter, but it is my OCD. ;)

    Thanks again and I look forward to your reply.
  • Jun 3, 2008, 04:00 AM
    stanfortyman
    What you suggest is fine, and rather common.
    YES, the main bonding jumper will occur in the main switch and feed-through panel outside, and no where else.
  • Jun 3, 2008, 07:09 PM
    GShelton
    Thank you!

    Oh and I found a Siemens with feed through. :)
  • Jun 9, 2008, 11:11 PM
    GShelton
    OK, first off, let me know if I should start a new thread or continue my stuff here. :)


    I picked up 2 Square D main panels with feed through (QO1816M200FTRB) to be used as my disconnects. The one feeding the detached garage will also feed the outside receptacles on the house (we do a HUGE X-mas light display and don't want to take the power from the house. The garage will not likely be occupied during the time the lights are on.) The one feeding the house will not currently have any circuits running from it, only feeding through to the house panel. I may eventually add power to the shed and feed it from here.

    #1. Within the NEC rule of all disconnects having to be in the same location, can I mount these on opposing sides of the meter can? (Main - Meter - Main) This would make them no more than 4 feet apart. I will label them each accordingly.

    #2. I am going to pre-wire for a backup generator using a Siemens GenReady panel. Can I run the feed (125Amp) from the generator into the bottom of the main panel that feeds the house and then into the house sup-panel through the same nipple (back to back) with the house feed? Does this violate any NEC codes? (2005 BTW) The feed from the generator will have no connections inside of the main panel. It will only connect inside the house sub-panel. If it can not run through the main panel, will it be required to be in conduit once it enters the wall of the house?

    #3 (not totally related) The house will be sided with fiber cement lap siding over 1/2" sheathing on wood frame. When I mount the disconnect for the A/C and other surface mount boxes, what is the best way to run the wires through the wall? Can I use a nipple and just end it in the wall cavity? Does the wire need to run in conduit to the panel? (The A/C will feed off of the inside panel.) Can the wire just poke through the siding and into the disconnect using a bushing?

    The wire for the A/C should be small enough to be workable. I am worried if I can not run the gen feed through the main panel, that it will be difficult to get it into the panel.


    #4 (and the last one for tonight) If I install receptacles in the soffits for x-mas lights, do these need to be "waterproof while in use" receptacles?
  • Nov 26, 2008, 05:34 AM
    abrownpe
    [QUOTE=GShelton;1073009]Hi TK,

    The POCO has approved me for a true 400amp service and supplied me with a K-Can (Landis and Gyr if it matters.) The meter can is just that. No mains. So here is my situation and what I want to do:

    The can has dual lugs already installed on the output.

    What were the part #'s of the dual lugs?

    I have essentially the same setup but my meter arrived without lugs.
  • Nov 26, 2008, 05:37 AM
    stanfortyman
    Quote:

    Originally Posted by abrownpe View Post
    What were the part #'s of the dual lugs?

    I have essentially the same setup but my meter arrived without lugs.

    The supply house that sold you meter pan should have also sold you the lugs. These pans rarely come with them.
  • Nov 26, 2008, 06:49 AM
    GShelton
    Quote:

    Originally Posted by abrownpe View Post

    What were the part #'s of the dual lugs?

    I have essentially the same setup but my meter arrived without lugs.

    I don't have the part number as I did not buy them. It was all supplied complete from my POCO. Sorry that doesn't help.

    Quote:

    Originally Posted by stanfortyman View Post
    The supply house that sold you meter pan should have also sold you the lugs. These pans rarely come with them.

    I would agree with this. If you are running something that requires dual lugs then it should have come from somewhere that is not a big box store, therefore they should be able to sell you the lug kit.

    Otherwise, check with the manufacturer of the can, they will have part numbers.

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