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15 years ago I personally installed a Reliance 6 station Transfer Switch for generator to my box when building my home. I have never had to use it. So naturally I have sorta forgotten particulars. It's a Maximum 8000 watts.
I recently purchased a Westinghouse WGen11500TFc which is 13,000 peak and 11,500 running watts.

When I look at larger transfers with 10 stations, they still are rated at 8000 watts.

Does someone make a Transfer switch rated for more watts. Did I waste $$$$ on over kill generator?

It's a very large home. 6000 square feet, 3 full baths and 5 bedrooms PLUS Plus. However kids are all gone but one, so most of these rooms don't get used.

Can someone explain how these transfers work? I have an electric oven, 2 wells and a sump. I believe a 4 ton AC.
Water heater and furnace are gas. Dryer is Gas. So I am sure I have a large enough generator for my need

My concern is the transfer Switch Size.

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    generator model is a Westinghouse WGen11500TFc 11500 is running watts @ THD 5% Not sure how to post pictures. I shrank them down so small you can barely see the enlarged view and it still says they are to big to download . This forum must have an older setup ??
    – Rick53
    Commented Jul 4 at 15:52

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TL;DR Don't use a Transfer Switch

Transfer switches have a lot of issues. But unless they are automatic transfer switches, which normally are used only for switching the entire utility service to an automatically starting generator, they are not really any better than an interlock. Among the issues:

  • Limited number of circuits. With an interlock all circuits are available.
  • Limited capacity (the stated problem). With an interlock, the generator breaker/wiring determines the capacity. 30A to 50A typical, larger is possible with a hardwired connection.
  • Included inlet is normally installed indoors. That is an invitation to running the generator either indoors (extremely dangerous) or with an extension cable running through an open door or window (only slightly less dangerous). With an interlock, the inlet is installed outdoors, solving the problem.
  • Possible problems with AFCI and/or GFCI circuits.

The way an interlock works is that you have a special sliding piece of metal, like [this Square D interlock from Home Depot]:

Square D Interlock

designed and installed such that it is impossible to have both the main breaker and a branch breaker next to it (one specific location, varies by panel/interlock type) on at the same time. Instead of:

  • Turn on transfer switch
  • Turn on generator
  • Use the specific loads that are on the switch

it becomes the slightly more complicated, but far more flexible:

  • Turn off main breaker
  • Slide interlock to generator setting
  • Turn off all breakers you don't want to have running on the generator
  • Turn on generator

This has two main advantages:

  • Limit on generator size is set by breaker connected to it and wire size - For example, if your generator has a 50A output then you can use a 50A breaker and use up to 12,000 W.
  • No limit on loads. For example, if you are using a transfer switch you probably would not put your electric clothes dryer or electric oven on the switch because they would use too much power. But with an interlock and some reasonable management of loads you could, for example, turn off the air conditioning, cook dinner with the oven and then turn the air conditioning back on.

On my panel I marked the list of breakers with symbols to indicate:

  • Always on when using generator - e.g., refrigerator, internet connection, computer, main lighting circuits.
  • Always off when using generator - e.g., oven, dryer - yet I know I could use them if I really needed to. But I definitely don't want them on with the generator without planning.
  • As needed - e.g., air conditioning, washing machine, microwave oven, etc.

How To Do This Right

The Westinghouse generator you are using has a 14-50 receptacle, so:

  • Install a 14-50 inlet on the outside of your house near the main panel and run a cable or wires in conduit to the main panel - 6 AWG copper cable, 8 AWG copper wires or (provided the inlet is compatible with aluminum wires) 6 AWG aluminum wires.
  • You will need a 14-50 male/female cable (a.k.a., extension cord) when using the generator. Make sure that cable is UL or ETL listed - too much power to risk using junk.
  • Move either the top left or top right pair of breakers/circuits from the main panel to the subpanel. Which ones you move will depend on how the interlock for your panel is designed to be installed.
  • Install a 50A double-breaker in the now empty pair of spaces in the main panel and connect it to the cable/wires from the inlet.
  • Install an interlock kit.
  • Label your breaker list so that you know at-a-glance which breakers should normally be on/off when using the generator.

Yes, the necessary components are relatively expensive (e.g., 50A inlet, interlock kit) but the transfer switches tend to cost even more, and this gives you a far more flexible solution.

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  • Main Panel 40 breaker panel is full . While I could move 2-3 circuits to my sub panel. It seems less complicated to just purchase a bigger Transfer Switch. Not sure why you think there's lots of issues with a transfer box . Like what exactly? I'm not following . If I had room in my main box I'd just move a few breakers around and install a larger 30 or 50 AMP Breaker . Unfortunately that's not an option unless a upgrade my main panely service
    – Rick53
    Commented Jul 4 at 15:30
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    @Rick53 It could be possible to combine some circuits or use double-stuff breakers so as to open up two spaces for a 240VAC breaker: that's all you need to get manassehkatz's proffered idea to work. Ask a new question "How can I get a generator interlock breaker in here?" with pictures of the inside of the breaker panel and its labels, and the experts here can guide on what modifications are needed. Commented Jul 4 at 15:56
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    @Rick53 re the "why are transfer switches bad? question, that's been discussed many times, maybe a search might help. The TL;DR version: they limit the available circuits to 6 or 10 breakers max and may not be compatible with AFCI/GFCI breakers on the generator or in the house. They may also be current limited below the generator's capabilities. Commented Jul 4 at 15:58

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