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RV Y Adapter Cord 50Amp(240V) Female to Two Male(120V) - Any Possible Issues?

Discussion in 'Supercharging & Charging Infrastructure' started by surfaholic, Jul 31, 2019.

  1. surfaholic

    surfaholic Member

    Joined:
    Aug 14, 2018
    Messages:
    21
    Location:
    Ottawa
    Hello
    I ended up getting one of these when I was in the US:
    https://www.amazon.com/gp/product/B07FH6TJC3 - RV Y Adapter Cord 50Amp Female to Two Male
    I couldn't find anyone that might have used one via the forums so I thought I would give it a try.
    I just tested it out at home using an adapter for 5mins and only pulling 12amps/240V via two separate circuits in my garage(One 15amp one is 20amp). It worked! but now I'm worried about long term use and issues that might happen?
    I had got this for camping at a campground not far from me that has separately breakered TT30 and 15amp(non-GFCI) that I will return to.
    I now realize this might not be that useful here as I can use a TT30 adapter for EV's(120V/24amp) vs this y adapter getting (240V/12amp) as I also probably shouldn't draw more then 12amps using this setup? So really I'm pulling the same number of watts in either setup?
    Regardless this seems like a much cheaper option to devices like the Quick 220V in a location when you have only 120V/12amp outlets. So in the end the what is the point of this more expensive device like a Quick 220V. Unless I'm missing some sort of safety feature this provides? Is it not just merging 2 x 120V from two separate circuits to make a 240V?
    Thanks
     
  2. Akikiki

    Akikiki A'-Lo-HA ! y'all

    Joined:
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    Kaneohe
    I realize the question is not being directed to me, but I say, Noooooooooooooooooo Comment.
    I know that I would not consider using this. Scary setup for my too expensive car for me to try.
    Good luck.
     
    • Disagree x 1
  3. Rocky_H

    Rocky_H Active Member

    Joined:
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    Location:
    Boise, ID
    Well, I do have some knowledge from some years on these forums, and I do have a Quick220.

    I wasn't very familiar with this kind of Y device. There are at least a couple potential issues:

    (1) It might not work at all, depending on where you plug it in. Here's how I am thinking it is wired. The 5-15 outlet and the TT-30 outlet are 120V, so they have a hot and a neutral. I think this Y device is taking those two hot lines and putting them on the Hot1 and Hot2 of the 14-50 receptacle. Sounds fine, except...what if the same hot phase was used for the 5-15 and TT-30 outlet at that place. There's no preventing that. You said you tested it at your house, and you got lucky and had two separate phases, so you saw 240V--yay for you. But if a campground happens to have the same phase on those two outlets, it's 0V between them when you plug into the 14-50, and you just get nothing.

    That's like a toss of a coin of whether this could even work or not at each place you go, so for most people, it's just not worth it.

    Now for potential problem (2). Yes, there is a specific safety feature that real Quick220 type devices do. With just trying to do a hardware linkup between 2 hot wires like this, the hot connection goes through the car and then out to the prongs of the other plug. So if one side of this is unplugged while it's still in the car, there is live 120V AC electricity on one of the prongs that someone could touch. Like if someone trips on a cord and it pulls one side out, and you go to grab it to plug it back in, that's risky, especially since that is so opposite of how we normally think of where the electricity is with outlets versus plugs, so we aren't generally careful about picking up a plug end.

    The Quick220 devices have a set of relay circuitry that are a continuity kind of checker, so if either side gets unplugged, it cuts off both sides, so it doesn't have live voltage on exposed metal prongs. I do consider that an important safety feature. Also, the Quick220 has indicator lights when you plug into two outlets, it will tell you if you got two opposite phases that will work, or if you need to keep trying other outlets.

    (3) And this is the main issue of why I don't recommend any of these kinds of things. You are using a Tesla plug of a 50A outlet type. That is drawing from 30A and 15A circuits, so you must remember to dial that down to 12A in the car. I don't really trust my own or anyone's memory or diligence to do that when you're getting to a campground, unloading the car, getting camping stuff set up, oh, and remembering to plug in the car, and getting distracted by something else, maybe when it's late at night when you arrived, so you're sleepy, etc. etc. It's 2019. We don't have to do that kind of thing with mismatched amp levels and having to remember to manually dial things down anymore. I would recommend to get the appropriate TT-30 adapter and just use it. It will automatically set the amps without risk.

    This is not really a concern. It can't do anything that could be any kind of a problem that could damage the car. However things are hooked up, the car will see either 0V, 120V, or 240V, which it can happily deal with. It's more about dangerous situations for people or overloading wiring or a breaker.
     
    • Like x 3
    • Informative x 1
  4. surfaholic

    surfaholic Member

    Joined:
    Aug 14, 2018
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    Location:
    Ottawa
    Thanks for your input and analysis, if I did use this I would be sure to always dial back the amps and make sure it wasn't anywhere someone would trip over it, goes for any charge location I would use. I will probably just use TT30 adapter wired for EV use when camping. I still might use this cable as an emergency thing in a safe location when no one can tamper/ trip over it. Unless someone has further electrical fire/safety input as to why not? As for damaging the car I agree it is pretty smart and sure it has precautions to avoid any damage. I just don't want to start an electrical fire
     
  5. Rocky_H

    Rocky_H Active Member

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    Location:
    Boise, ID
    Yep, you take the precautions you can take, and I realize that around the Ontario area you may be in places where you have to get what charging you can get with less charging infrastructure sometimes. So double check what you can and be safe.
     

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