GFCI Adapter + 8A Charging

Discussion in 'Prime Plug-in Charging' started by AmazingPriusPrime, Sep 7, 2018.

  1. AmazingPriusPrime

    AmazingPriusPrime New Member

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    My home is close to 50 years old and an Electrician visited us last time mentioned that I need to upgrade my panel to add more dedicated circuits. So I have to share normal outlet in my garage to charge my Prime. I am thinking to use a Single Outlet GFCI Adapter and set Charge Settings -> Charge Current to 8A. Do you think there will be any problem with this plan? Do you have any recommendation for the GFCI Adapter?
     
  2. DavidA

    DavidA Prius owner since July 2009

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    No. You're fine, I'd bet. But make sure the circuit is at least on a 15A breaker.

    Our house is 108 years old. Our total power to the house is only 100A. We added a 40A 240v circuit and an additional 20A 120v for car chargings. Normally, dividing out additional 60A to the already 100A total is stupid awful idea and I would agree. But the most a Prime can pull is 16A @ 240v. The other 20A 120v is a backup (on 12A mode) if the Level 2 charger fails, or if we need it for high powered lawn equipment, so not everything is ever on at the same time.

    Are you sure you can't amp it up a little and do better than 8A 120v?
     
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  3. AmazingPriusPrime

    AmazingPriusPrime New Member

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    Thanks. I tested using a GFCI Tester and see that the outlet has correct wiring but I have no idea whether it is on a 15A breaker. I did some research and looks like even with Multi-meter, I cannot figure it out. I looked at my electrical panel and it doesn't have any information as well. Do you know any creative ways to figure it out?
    Edit: I looked at the Panel and I can see the breakers labelled with numbers like 60 (Two of them), 50 (one of them), 30 (Two of them), 20 (Multiple), 15 (Multiple) so looks like it should be at least on a 15A breaker?
     
    #3 AmazingPriusPrime, Sep 8, 2018
    Last edited: Sep 8, 2018
  4. DavidA

    DavidA Prius owner since July 2009

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    Probably it, but the 60A is pretty big. Large central air unit or electric heat/water heater?
     
  5. Old Bear

    Old Bear Senior Member

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    In the U.S., the smallest standard circuit breaker is 15-amperes. That is typical of a 120-volt circuit used for lighting (or in the case of many olderer home, for general purposes.) In most newer homes, 15-amp circuits are generally used for lighting and 20-amp circuits for outlets. This is usually true but not always.

    Those double-breakers with the 60, 50 and 30 are for 240-volt circuits which supply devices like ranges, water heaters, central air-conditioning, clothes dryers, etc.

    Circuit-Breakers.jpg

    Your Prime is designed to be plugged into an ordinary household outlet. You should have no problem charging it -- unless there is something else using the same circuit which, when added to the current drawn by the Prime, exceeds the circuit breaker capacity.

    For example, if your Prime is drawing 12 amps and is plugged into a 15-amp circuit, there is only 3 amps left available for other things plugged into the same circuit. If it's plugged into a 20-amp circuit, there would be 8 amps left for other devices on the same circuit.

    The Prime's ability to charge at a lower current of 8 amps is to allow you to plug it into a circuit which is shared with other devices which cannot be disconnected. For example, you're at your cabin at the lake where there is only one 15-amp circuit which must be shared with the refrigerator.

    If you want to identify which circuit breaker serves the outlet in your garage, here are a couple of techniques:

    1. Plug a radio or TV into the outlet and turn the volume up loud so that you can hear it when you are standing at your circuit breaker panel. Flip the breakers one by one and see which causes the sound to stop.

    2. Plug a lamp or night-light into the outlet. Have a friend watch it while you flip the breakers one by one. Stay in communication with your friend via cellphone while you do this.​

    If your house is only 50 years old, that means it was built some time in the 1960s. While there have been changes in technology and in building codes, things from the 1960s are relatively modern. Problems are much more common with wiring from the 1930s with two-prong outlets with no grounds -- or houses from the 1890s with "knob-and-tube" wires and screw-in plug fuses.

    plug-fuse-panel-sm.jpg
     
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  6. bisco

    bisco cookie crumbler

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    even if there is something else on the garage circuit, you just have to make sure it isn't used while you're charging.
    you can find the breaker for the garage by having someone turn the breakers off ne at a time until you have no power there.
    p.s. more dedicated circuits are only necessary if you are tripping breakers.
     
  7. AmazingPriusPrime

    AmazingPriusPrime New Member

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    The breaker is marked as Furnace but my Furnace is Gas so may be it was Electric originally and then got converted to Gas before I purchased.
     
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  8. AmazingPriusPrime

    AmazingPriusPrime New Member

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    Thanks, tested and it's all the Garage outlets and lights that are sharing the breaker which I won't be using when charging so looks I shouldn't have problem going with default 12A. Thanks everyone for your inputs, really appreciate and glad to have this PriusChat forum helping new Prius'ers...
     
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  9. bisco

    bisco cookie crumbler

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    this may not be a good idea, since the breaker is over rated for the gas furnace wiring, plus, you're losing much needed breaker space. but i think an electrician would be better qualified to check it out.
     
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  10. Old Bear

    Old Bear Senior Member

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    Your furnace may use gas as its energy source for heat, but it still has electric controls including your thermostat and probably an electrical ignition and electric flue damper actuator. If your heating system is forced hot-water, you'll also have one or more circulating pumps. If it's forced hot air, you will have a fan blower.

    You'd think that if you have gas heat, you'd be in great shape if you lose electric power (which might happen here in New England during a snow or ice storm), but unless you have some source of emergency electricity for all that stuff which your gas furnace's systems need, it can get pretty cold in your house.

    Have your electrician check things out. The total load of all that stuff on your furnace may be only use a couple of amps and pose no problem co-existing with your 12-amp Prime on the same circuit. If not, and if your garage wiring and/or furnace wiring runs back to your circuit breaker panel separately, your electrician may be able to separate it there and just install another circuit breaker. That would be a relatively small cost.

    The one thing you don't want to do is be in a situation where you plug in your Prime to re-charge on a cold winter day and suddenly find your house without heat and your Prime without charge because of a tripped circuit breaker.
     
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