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easiest way to upgrade grandparents garage for visiting?

Discussion in 'Model S: Battery & Charging' started by balefire, May 18, 2014.

  1. balefire

    balefire Member

    Sep 27, 2013
    Chicago, IL
    We visit our grandparents often in Indy, but they only have a standard 110v outlet at their townhouse garage.
    We routinely charge there at 4mi/h. We use the local Tesla mall charger to top off, but this is a small hassle.

    Their garage is detached and I don't think their breaker is in the garage. What is the easiest way to upgrade their outlet? A friend said a 240v 30amp line would be costly and a hassle for this detached garage. Is there a simpler outlet to change to that would allow us to do any better than 110v?
  2. tiblot

    tiblot Member

    May 22, 2013
    Herndon, Virginia, United States
    By breaker, you mean the entire Breaker box/ Panel, right? If its not near the garage, anything you try to add is going to be alot of $$ :(

    Probably nothing you can do that's cheap. How is the 110v fed? From a breaker in the townhome somewhere?
  3. pgiralt

    pgiralt Supporting Member

    Jun 16, 2013
    Cary, NC
    If the wiring to that outlet in the garage is 12 gauge, you could upgrade to a NEMA5-20 plug and get 16A instead of 12A out of the 110V outlet to give you slightly better. You'd have to change the breaker and the outlet. Again this would only work if the wiring is already 12 AWG.

    The lowest-current 240V outlet that Tesla provides is 30 Amp, so you'd need at least 10 AWG wire for that. If you happen to have 10 AWG there, you could run a NEMA10-30 which is 3-wire and does not require a neutral and Tesla makes an adaptor for that. You'd have to re-label the white conductor to be black instead of white (by just wrapping the ends with electric tape) to indicate that they are both hot. On the panel side, you'd have to swap it out to a dual-leg breaker to make it 220V. This would really only work if that outlet already have 10 AWG and is a single home-run to that one outlet (not daisy-chained to multiple outlets in the detached garage).
  4. TurboFroggy

    TurboFroggy Member

    Dec 5, 2012
    Everett, WA
    If you can be 110% sure there are no other outlets on that circuit, it is possible to change out the breaker to a 240V two pole breaker and the outlet to a L6-20 so you could charge at 3.84KW or about 10 mph.
    However getting a 14-50 installed would be ideal, which would require some conduit. I would recommend jumping on Yelp or Angie's List and look for electricians in the area and get a couple of quotes for installing a 14-50 there. I would then offer to arrange the entire install and pay for all of it.
  5. dsm363

    dsm363 Roadster + Sig Model S

    May 17, 2009
    Agree. Get a couple of quotes and install a 14-50 since it is a place you visit often. I had two 14-50s installed in an attached garage a few years ago. They had to tunnel under the back yard about 25 feet and ended up costing $1,000. Hopefully it won't be that much.
  6. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

    Jun 21, 2012
    #6 FlasherZ, May 18, 2014
    Last edited: May 18, 2014
    There are some limitations when the building is detached. Adding a larger circuit requires placing a subpanel in the garage. You may only run a single branch circuit or multi-wire branch circuit to a detached building (and it requires a disconnect in the building) or you must place a subpanel in there.

    You will not be able to place a 240V circuit out there without upgrading the electrical feeder and adding a subpanel, which is what I would do if I were to upgrade it. Otherwise, you'll need to do a bit of investigation to find out whether it's one 120V circuit or a multi-wire circuit. Look for the existing breaker that goes out to the garage, is it a two-pole (two breaker handles tied together) or a single-pole (just a single small breaker)? That will determine your options.

    (Technically, if you had 12/3 wire to the building, you could run a 20A MWBC, place a NEMA 5-20 on one leg for charging and lights and outlets can be on the other side. However, it's likely if 12/3 already exists it was wired in a different way. You're probably going to need an electrician either way.)
  7. David_Cary

    David_Cary Member

    Dec 17, 2012
    Cary, NC
    Can you park outside close to the laundry room? Like people have said, it sounds like you have no "easy" option for the detached garage.

    Whenever I see a townhome and detached garage, I usually think pavement in between which makes running a new wire very costly. But if you can run an extension cord from a laundry room, that is pretty cheap.
  8. GSP

    GSP Member

    Dec 28, 2007
    I would look into installing a 14-50 or a 30A, 240V outlet on an exterior wall of the townhouse, near a parking spot. An RV extension cord could be used if needed. Hopefully this is an option for you.

  9. CHGolferJim

    CHGolferJim Member

    Jan 28, 2014
    Chapel Hill, NC

    Seems like I've read here that there might be an issue with a daily unplugging of the dryer plug. Anyone have thoughts on that? I'm considering starting out with the dryer plug, then deciding on garage wiring after gaining some experience (have an SC 35 miles away).
  10. Cottonwood

    Cottonwood Roadster#433, Model S#S37

    Feb 27, 2009
    With a Supercharger 35 miles away, 120 available, and the dryer plug, it sounds like you are in pretty good shape for a while. Remember that the 120 outlet is worth 75 miles in 24 hours or 50 miles in 16 hours. That will get you a long way. If you can get set up for the dryer outlet at 17 MPH charge rate, you will be in nice shape.

    For the dryer outler, figure out if it is a newer 14-30 or an older 10-30 outlet, and get that adapter, then see what is the breaker that is feeding it, hopefully 30 Amps; I have seen breakers rated a less than the outlet sometimes. I just carry all of the adapters; they don't take up much space, and really don't cost that much. It will be great if you don't need an extension cord, but if you do, you will have to decide which order of adapter and extension cord you want to use. Using a 14-50 extension cord has the most flexibility, but is the heaviest, most expensive, and you will have to manually turn down the current in your car. An extension cord that is rated at 30 Amps with the dryer plug and receptacle is probably a custom build, that will only work for a dryer setup, but will be the cheapest, easiest to store, and will not require setting current limits.

    Good Luck!
  11. ElSupreme

    ElSupreme Model S 03182

    Jan 13, 2012
    Atlanta, GA
    I'm with Cottonwood on this one. Using a dryer plug is the easiest way to go.

    I built a custom 30A extension cord to use to charge at my grandparents and my brothers.

    Sure those outlets aren't designed for 100s of plug/unplug cycles. But swapping it out for a new one is ~30 minutes and ~$10 tops. And honestly plugging into a 120V on the outside of the house works pretty well if you are staying a few days.

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