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-   -   Main breaker and main disconnect (https://www.askmehelpdesk.com/showthread.php?t=59858)

  • Feb 3, 2007, 06:34 PM
    cobraofdenver
    Main breaker and main disconnect
    What I have is a home built in 1960 moved in 2 years it had a meter hanging from the rear of house with no main, 240v 50amp circuit to stove, 240 30amp to dryer, 5 breakers for the rest of house 1 20amp and 4 15amp.

    What my plan is to replace the meter housing and put a g.e. 200amp Disconnect on the rear of the house and put the new main panel in the basement along with 2 sub panels and another sub panel in the garage
    All ready talked with utility company and they will change out my overhead to a bigger size and do the meter change over for me.

    Here is my small list of questions---

    Can I have a main disconnect outside plus one in my main panel and garage subpanel?

    What size wire to run from my disconnect to main panel in basement about 30 -35 feet away?

    In my main panel would like a 200amp main------ from main to garage is about 15 apart would like a 100amp main in subpanel plus the 100amp 240v in main
    What size wire should I use for this?

    Will have 70amp breaker in main to first subpanel which will have all my lower amp circuits 20 total circuits lights, kitchen,etc. will this work

    Will have 40amp breaker going to 8 circuit sub panel which will have a t.v.s.s snap in breaker and 6 afci 15 amp breakers controlling all bedroom circuits- does this sound good?

    Thanks for all your help. I have done a break done of my proposed circuits on an excel spreadsheet if someone could give me an email to verify
  • Feb 4, 2007, 05:07 AM
    tkrussell
    1. Yes , it is not necessary but not a problem to have another disconnect inside at the panel. Just that all grounding must now go to the outdoor disconnect, which is now the main service disconnect. Be sure to understand that the neutral and ground is only connected together at the main service disconnect, and both are separated at all panels downstream.

    2.#4/0- 4 wire aluminum SER cable will work for this.

    3.#2- 4 wire aluminum SER cable will work for this.

    Be sure to know how to terminate aluminum conductors, which need wire brushing, antioxidant compound, and proper torquing.

    4.Not sure,need to see the total load and confirm that it will not exceed 80% of the 70 amp CB , or 56 amps.

    5. Same as #4, except the max amps load is 36 amps. Why only a TVSS in this panel? One should be in each panel if you are truly interested in protecting sensitve equipment from transients. All bedroom wiring needs to be protected with AFCI breakers also. Need to check local codes to see if smoke detectors are waived from AFCI protection.

    PM me and I can give an email address.
  • Feb 4, 2007, 11:48 AM
    labman
    I leave technical questions like yours go, knowing you will get a good answer. I would suggest with all the work you are doing, you incorporate some sort of an approved double throw switch to isolate your wiring from the electrical service. If you ever want to wire in a generator for emergency use, you must have a positive disconnect making it impossible to back feed into the utility. Being able to throw an outside disconnect is not enough. You might look at a double throw disconnect for outside. One of the cheapest ways to go is an interlock plate. They are just a simple sliding metal plate that prevents the main breaker and a selected other breaker the generator feeds from both being on a once. I know they are are available to fit both Square D and some GE boxes.

    If you are interested, post back or do a search here on connecting a generator.

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