Generator hookup questions

Discussion in 'Shop Talk' started by Coloradosteader, Nov 28, 2005.

  1. Coloradosteader

    Coloradosteader Active Member

    Jun 9, 2005
    Hey all,
    I'm planning on getting a propane genset single phase 20KW to run my shop and for larger equipment. I'm completely off grid and need to run the power cables to a breaker box for distribution. Is this where a transfer switch comes into play? I'm not going to have it as a standby etc. just need to fire it up when I need it.
    Any help on equipment I might need would be appreciated.

  2. moopups

    moopups In Remembrance

    May 12, 2002
    In beautiful downtown Sticks, near Belleview, Fl.
    If your 'off grid' completely why would a transfer switch be needed? The transfer switch is normally to sent electricity to your system seperate from grid power, its to prevent any electrical worker elsewhere from getting zapped via your generator.`

  3. tiogacounty

    tiogacounty Well-Known Member

    Oct 27, 2005
    A transfer switch is a safety device that switches a load from grid power to generator power. In this case it wouldn't be necessary. One thought I had was power stabilization. An automatic transfer switch, like one found in places like schools and hospitals, generally has a delay to allow the generator to stabilize before applying the load. You might have an issue if you hook the generator directly up to the panel and have any loads connected. So you don't want to leave things like dust collectors or electric heaters on while the generator comes up to speed. You probably would be OK if you direct wired the generator to the panel. I would want an ampere meter on each hot leg of the generator output, so you can determine that the generator is fairly balanced between phases and not overloaded. Also a volt meter is important as low voltage is rough on equipment, particularly motors. Good luck.
  4. tyusclan

    tyusclan Well-Known Member

    Jan 1, 2005
    As has been said, you would not need a transfer switch since you're not transferring from grid power to generator power. I would put a disconnect between the generator and the load to let the generator level off before putting the load on it.

    I would check the voltage output to make sure it's within +/-10% of the rated output. You don't have to worry about balancing phases since it's a single phase generator.
  5. farminghandyman

    farminghandyman Well-Known Member Supporter

    Mar 4, 2005
    I am not positive on exactly what your desires are either, as your off grid,

    but I would put some type of disconnect switch in line to be able to pull the generator totally off the circuits when starting or testing,

    disconnects are on and off switches, two positions either on or off,
    a transfer switch is three positions-- on, off, on, and it selects either one power source or the other, not both at once.

    I am on gird and have a transfer switch to select between the generator shed and the power company, it is a special double throw switch, and you hook up your out going power to the center and then only one place can supply the farm, either my generator or the power company,

    now recently i added a small generator to the generator shed for fuel conversation and to make sure that I or some one else does not back feed the generator that is off or what ever. I installed a second transfer switch in the generator shed so that only one generator can be on line at one time,

    both are manual switches, you go out and move the handle to select the generator or to the pole and select which location you want to powered from,

    if you have another form of power generator and want to protect the generators from each other a transfer switch would be a good way to do it so you can not accidentally back feed an inverter or a smaller generator, or the other way around,