Generator transfer switch for house

Discussion in 'Electrical Forum discussion & Blog' started by mikesignal, Mar 19, 2014.

  1. mikesignal

    mikesignal New Member

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  2. DonL

    DonL Jack of all trades Master of one

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  3. mikesignal

    mikesignal New Member

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    thanks. I emailed the local building inspector. Hopefully he will respond.
  4. DonL

    DonL Jack of all trades Master of one

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    Properly rated extension cords work and could be safer.


    Good Luck.
    Last edited: Mar 20, 2014
  5. hj

    hj Moderator & Master Plumber Staff Member

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    quote; Properly rated extension cords work and could be safer.

    As long as you mean to the appliance and not to feed the panel.
  6. DonL

    DonL Jack of all trades Master of one

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    Unless it is a big generator it won't do much good to have it connected to the main.

    A extension cord is easy for a portable generator running only what is really needed.
  7. hj

    hj Moderator & Master Plumber Staff Member

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    quote; Unless it is a big generator it won't do much good to have it connected to the main.

    Unless they think that they could just turn the breakers they want to service on and turn the other ones off, which would be a recipe for disaster.
  8. mikesignal

    mikesignal New Member

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    having a "big" generator is really not necessary, at least in my opinion. My only concern to get a transfer panel is to run my gas furnace. I could see if you had a heat pump and need the watts to run it, but other than that I don't see a point in anything larger than 7k.
  9. DonL

    DonL Jack of all trades Master of one

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    As long as the generator can run everything at 50% load then you should be good.

    Most generators are over rated, it depends on the motor.

    You do not get something for nothing, And Losses are involved.

    It may be easier to put a changeover on your furnace, Instead of a 100+ amp Whole House Switch.


    Good Luck on your project.
  10. hj

    hj Moderator & Master Plumber Staff Member

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    Here, the furnaces plug into the wall with a pigtail connection. If you have that, or could change to one, then a pair of duplex outlets, one wired to the utility, and one wired to a generator connection, would serve the purpose. Just plug the furnace into which ever one has power at the time. No possibility of "back feeding" and very little expense.
  11. mikesignal

    mikesignal New Member

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    that is an easier solution. I guess I could get a 100' extenstion cord. It might reach. the furnace is in the attic (3rd floor).

    really all I'm looking to run is my refridgerator, furnace and microwave(800 watt). Lights would be a bonus (you know how women are) that isn't a necessity..... That' why i bought the 5700 watt one. It's enough to run those 3 things. Even if the fridge and furnace both kicked on at the same time I was using the microwave I'm not overloading it.
  12. Reach4

    Reach4 Active Member

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    Modem, router, computer, cordless phone base?
  13. mikesignal

    mikesignal New Member

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    yea, that would be nice too. Wouldn't draw hardly anything either.
  14. Reach4

    Reach4 Active Member

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    If it is summer (furnace off), maybe power the fridge part of the time. In winter, move some food outdoors to keep it cold.
  15. mikesignal

    mikesignal New Member

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    Location:
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  16. DonL

    DonL Jack of all trades Master of one

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  17. mikesignal

    mikesignal New Member

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    That may be the route I go with. Just easier. The inspector never emailed me back and adding in a whole house tranfer panel may not be worth the cost and too much of a PITA.

    I actually have a panel with a walking beam disconnect on it that I was going to use, but I don't think the walking beam is up to code for household use. It's just a snap in walking beam. I also found a neutral switching kit made by generac that I was going to use with the panel. I wonder why retail stores sell a tranfer panel kit for portables if they are not up to code. If switching the neutral is now code. Home depot sell the reliance kit.

    http://www.northerntool.com/shop/to...ci_sku=28614&gclid=CKbxvPGspr0CFUpnOgod1hQA-w


    also wish I had a picture of my wife's face when I told her there will be an extention cord running through the house up to the furnace if/when the power goes out. :)
    Last edited: Mar 22, 2014
  18. DonL

    DonL Jack of all trades Master of one

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    I would just drive a ground rod at the generator.

    I would not trust a Neutral switching relay, for ground fault protection.


    For your generator the simple is better.
  19. ActionDave

    ActionDave Electrician

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    Huh?? Driving a ground at the generator, or anywhere, had nothing to do with ground fault protection; unless we not talking about the same thing.
  20. mikesignal

    mikesignal New Member

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    Location:
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    I found this and copied it from an old thread on here:

    445.1702.10(A)702.10(B)445.1702.10(A)702.10(B)445. 1702.11(A)702.11(B)
    GENERAL
    This category covers internal-combustion-engine-driven generators rated 15 kW or less, 250 V or less, which are provided only with receptacle outlets for the ac output circuits. The generators may incorporate alternating- or direct-current generator sections for supplying energy to battery-charging circuits.

    "When a portable generator is used to supply a building or structure wiring system:

    1. The generator is considered a separately derived system in accordance with ANSI/NFPA 70, "National Electrical Code" (NEC).
    2. The generator is intended to be connected through permanently installed Listed transfer equipment that switches all conductors other than the equipment grounding conductor.
    3. The frame of a Listed generator is connected to the equipment-grounding conductor and the grounded (neutral) conductor of the generator. When properly connected to a premises or structure wiring system, the portable generator will be connected to the premises or structure grounding electrode for its ground reference.
    4. Portable generators used other than to power building or structure wiring systems are intended to be connected to ground if required by the NEC."

    the way I read it in laymans terms is you need a 3 wire switching panel, 2 hots and the neutral. The ground must be connected to the house ground for reference. Any interlock kit that fits into a main panel would not be up to code because it only isolates the 2 hots, and does not islolate the neutral. Same for many of the tranfer panel sold in retail stores. What I don't understand is if this is code then why are there interlock kits and why are there transfer panels available that do not switch the neutral. I know it will work without switching the neutral but what if someone makes up a cord and mistakenly switches the neutral wire with one of the hots?
    Last edited: Mar 23, 2014
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