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Garage outlet

Discussion in 'Model S: Battery & Charging' started by Hawaii J, Sep 15, 2014.

  1. Hawaii J

    Hawaii J Member

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    I have read a couple forums where owners have installed 100v up to 220v outlets for charging at up to 50A. I'm waiting for an end of the year delivery, so I am super new here.

    Tesla recommends 240v 40A outlet (NEMA 14-50) as I'm sure everyone knows. Is it because of cost that people install smaller current? Is there a tipping point where you have to upgrade all home electrical to get to 240v?

    My house has original wiring from late 70s. My circuit box is in a closet on the main floor and garage is below about 35ft away (house is on side of mountain so garage is technically 1st floor and part of house is over garage. Any advice, insight, recommendations are appreciated. Getting single charger as I live on an island about 40 miles wide.
     
  2. Killface

    Killface Member

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    Some people choose to go with less than 40A because it will save money and they don't need faster charge times. NEMA 14-50 will get you about 29 miles per hour of charge. A Tesla HPWC will get 58 miles per hour of charge, but requires the car have dual chargers to get that high rate of charge.

    There's a good calculator"widget" on Tesla's site that will show you how long it takes to charge using various outlets. (Tesla Charging | Tesla Motors - almost at the bottom)

    In addition, if your house is already using almost all the power your electrical service panel provides, installing a HPWC or even NEMA 14-50 will sometimes require a service panel upgrade or installation of a sub-panel, which can get expensive.
     
  3. pgiralt

    pgiralt Active Member

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    As long as your service panel or service feeders don't need to be upgraded, the cost of installing a NEMA 14-50 or something smaller like a NEMA 14-30 or even a standard 110V outlet should be fairly similar. The cost of parts should only be incrementally higher with much of the cost being the labor. If your home supports it, a NEMA 14-50 is your best bet.
     
  4. Kbsilver

    Kbsilver Member

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    Just for clarification, under most circumstances in the US (no location so we cannot tell where you are from) you cannot choose between 220 or 240. You get what you get off the service pole/transformer in your area. In most cases it's 240 anyway. The most common locations where you get 220, or even 208 is where power comes from a 3 phase source, which is typically only industrial, not residential. When people do panel upgrades in their homes it's most often for more AMPS, again for voltage you get what is given. First question is what is the size of the feed to the main panel in your house (usually listed on the main breaker)? This is all presuming you have 240 volt service. Being from the 70's does not mean anything, but being on an Island might. Next you need to look at the AMPS you have and compare to your loads. Is this an all electric house, or is there gas heat/hot water/cooking. With an all electric house you would want at least 150 if not 200AMP panel to add the 50 AMP charger. With most things gas you could probably get by with a 100 amp panel to feed the 50 amp charger. This is just a starting point, you will need to get an electrician to be sure and to meet local codes.

    More power = faster charging. Simple as that.
     
  5. Hawaii J

    Hawaii J Member

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    Great info, thanks for posting, totally joking with you here but my guess is that you aren't a private investigator
     
  6. bollar

    bollar Disgruntled Member

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    A picture of your panel would probably be helpful. Since your "unknown" location likely doesn't have significant heating/cooling loads, my guess is that you have a 100 amp panel.
     
  7. Kbsilver

    Kbsilver Member

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    I assume nothing. Many people use the place or thing they dream of (like Tesla) in their screen name. :tongue:
     
  8. Cosmacelf

    Cosmacelf Active Member

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    Anyhoo, on your main electrical panel, what is the panel breaker amps (the biggest breaker, and usually set away from the other breakers)? Do you have two side by side empty slots in your breaker panel?
     
  9. 2Cybers

    2Cybers Member

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    The critical item determining if your cost for NEMA 14-50 is a few hundred or well perhaps over $2,000 is what is the service to your house - by that I mean the physical size of the wires and the amp capacity of your circuit breaker box. If your house is only 100 amp (possible given the age, but i doubt it), you will have at a minimum replace your current breaker box and possibly get larger wires from the utility pole to your house. In some locations, the utility upgrades these wires and in others the home owner does. A call to your electric company might tell you what the amp capacity to your house is - this is the wire size item, not the capacity of the breaker box. It is not uncommon for the utility to run larger/oversized wires to a house just so if people upgrade the utility does not have to redo the wires from the street. Knowing your address and when the house was built are questions they may ask.

    Your voltage is nominally 240/220 if you have 3 wires going from the pole to your house.

    Higher voltage and higher amps not only charge faster, there is also less wasted electricity. No electrical process is 100% efficient. So just in terms of electricity costs, if I charge my Tesla on 120 volts I will have to use more electricity than if I use the 240 volt NEMA 14-50 system.

    Dual and single chargers affect the maximum charging speed when connected to an AC electrical outlet (your garage, a hotel electrical line, etc.). It will have no effect on the Supercharger usage - that said if you get the MS with the 60Kwh battery, you have to pay for Supercharger capability.

    One thing going on that I don't see a lot of mention in these forums is a program between Tesla and destinations. Tesla is offering free equipment and paying half the wiring costs, as I understand it, to places like hotels and resorts. These facilities then offer fast charging (something called HPWC) can be very fast. Dual chargers are needed to make the HPWC as faster than a NEMA 14-50 system. When I am 500 or a 1,000 miles from home I would much rather be able to charge at 58 miles per hour of charging than only 29. That won't happen every week, but it will happen often enough that I ordered dual chargers.

    People talk about 50 and 40 amp NEMA 14-50 charging capacities. The proper wiring will be a 50 amp breaker and #6 wire rated at 55 amps. The Tesla itself only allows drawing 80% of the max amp capacity. So a 50 amp system will only charge at a 40 amp rate. Same thing applies to a 15 amp 120 volt wall plug - it will charge at only 12 amps.

    Spend some time reading in this forum and at Charger and Range section of
    START HERE!! FACTS, FAQS, TRICKS, TIPS and ADVICE | Forums | Tesla Motors
     
  10. gavine

    gavine Petrol Head turned EV Enthusiast

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    Although slow and inefficient, a regular 110 outlet might be all you need living on a small island. It would only give you 3 miles per hour, but the buffer you would get over the weekend should suffice. Does your garage not have a standard outlet already? You can try it and always add the NEMA 14-50 later if need be.
     
  11. NSX1992

    NSX1992 Member

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    I replaced my 240V 30 amp breaker for electric dryer (I have gas dryer) with 50 amp breaker in 100 amp panel on the theory that I will charge only between midnight and 6am (reduced EV SCE rate).
     
  12. 2Cybers

    2Cybers Member

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    NSX1992 wrote
    I replaced my 240V 30 amp breaker for electric dryer (I have gas dryer) with 50 amp breaker in 100 amp panel on the theory that I will charge only between midnight and 6am (reduced EV SCE rate).

    If you did not replace the wires in the wall, you had better check your fire insurance. You need #6 for 50 amp service and the typical for a 30 amp drier is #10 - This is seriously dangerous.
     
  13. linkster

    linkster Member

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    After 20 mos. and 35,000 miles, our 14-30 is more than adequate. It seems like a 5-20 with an approximate charge rate of 6 mph might work for you if you don't need a quick "turn around".
     
  14. gonzopancho

    gonzopancho New Member

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    OP is in Hawaii. While I live in Texas, I spent a decade on Oahu.

    There is no "220" service in the US. The "220" comes from people looking at electrical motor plates, or re-iterpreting European power (which is 220). Undervoltage conditions can affect the operation and service life of motors; these are usuallyrated at ±10% of nameplate voltage - thus the common rating of 230V or 460V for motors, whichcan usually be safely operated at the lower voltages sometimes found at service connectionpoints.

    Residential US is 120/240V *center tapped* single phase. It may also becalled Split Phase 240. This configuration consists of 2 voltage legs that are 180 degrees apart. The voltagebetween the two legs (called phase to phase or line to line) is 240V and the phase to neutral voltage is 120V.The120/240 notation identifies the phase to neutral voltage followed by the phase to phase voltage. Some list thephase to phase voltage first so it may also be called 240/120 single phase.

    In the USA the most common configuration is 208Y/120. This indicates that line to line (L-L) voltage is 208Vac ina WYE configuration and the line to neutral (L-N) voltage is 120Vac. It is also sometimes designated 120/208Vac,120/208WYE, 208/120 WYE, 4 wire WYE or 120/208Y.





    For higher power capabilities another configuration in the USA is 480Y/277. In this case the line to line voltage is480Vac in a WYE configuration and the line to neutral voltage is 277Vac.





    Since each phase in a 3 phase wye configuration is 120 degrees from each other, the L-L voltage is not thealgebraic sum of the L-N voltages but a vector addition. A quick method that can be used if the phase angles are120 degrees apart is to use the L-N voltage multiplied by 3.

    V
    L-N ∗√3=VL-L (i.e.120Vac1.7333=208Vac)

    V
    L-L ÷ 1.7333 = V L-N (i.e. 480Vac ÷ 1.7333 = 277 Vac)

     
  15. NSX1992

    NSX1992 Member

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    Yes I did install new #6 wires to the new outlet. I only used the space in the panel to replace the 30amp breaker with the 50amp and left the old wires to the dryer disconnected.
     
  16. wycolo

    wycolo Active Member

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    There is only one 'K' island in HI that is 40 miles wide. You don't need a weatherman to know which way the wind blows.
    --
     

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