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15 kW EMW JuiceBox EVSE

Discussion in 'Charging Standards and Infrastructure' started by apacheguy, Jan 25, 2014.

  1. apacheguy

    apacheguy Sig 255, VIN 320

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    Anyone have a JuiceBox installed for charging the MS at 60 amps? I've started to read up on them and I'm thinking of buying the base assembled version for $479. I would want it to charge both my MS and my Nissan Leaf.

    Couple lingering questions:

    1. When configured via the website it seems to only support a 40 amp NEMA 14-50. How would I go about connecting it to a 60 amp circuit to take full advantage of the 15 kW?

    2. I understand that there was a safety concern surrounding ground fault interrupt on the early models. Has this been addressed?
     
  2. 772

    772 Member

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    1. When you order/after you order, contact them and ask them to set the output current to 60A before they ship your EVSE. I think the assembled version normally comes set to 40A. You can change this yourself fairly easily, but it involves opening up the box. After that, just hardwire the EVSE to a 75A breaker.

    2. Yes, I believe so.
     
  3. Odenator

    Odenator P2607

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    I have a premium Juice Box ordered from their Kickstarter fund.

    1: You can order it set up for 15kW, make sure you order the appropriate 15kW compatible J1772 cable. For an added extra fee, it can all be preassembled prior to delivery.

    2: Yes this was corrected early on.
     
  4. mckemie

    mckemie Member

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    I just received my JuiceBox 6/12/14. My main interest is to get a little more out of a 50 amp 14-50. I have a single charger, with my JB experience I just ordered a twin charger upgrade. I got a friend with a twin charger to come help me test. At my normal 14-50 charging outlet, I was able to get 45 amps with very little heating. I tested up to 52 amps but things were getting hot: the breaker, the outlet box, and some cable. The JuiceBox cable stayed cool.

    I hope to carry a JB with me when charging at RV parks and save 10-20% charge time.
     
  5. Cosmacelf

    Cosmacelf Active Member

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    According to the national electrical code, the maximum you can charge your car is at 80% of the breaker rating. So on a 50 amp breaker, the maximum allowable is 40 amps. This is because car charging is a continuous load, unlike most other intermittent loads.

    RV parks are notorious for dodgy wiring, and you are often lucky to even get 40 amps out of a 50 amp outlet without the breaker tripping. Pushing it past 40A would be especially dangerous at an RV park.
     
  6. qwk

    qwk Model S P2681

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    Yep. I can't imagine trying to charge at more than 40A at an RV park. That is a recipe for problems. Out of about a dozen RV parks I have been to, only one has been trouble free(this is at 40A). Some of the parks still have fuses, so if you pop a fuse, you will be stuck if there are no other plugs available.
     
  7. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    Because most RV parks have their breaker panels in reasonably accessible locations, I have pondered traveling with a collection of 100 Amp circuit breakers, some flexible #2 wire, and an HPWC. This would involve a temporary install of the breaker, wiring, and HPWC, much like floor finishers do for their big sanders, or construction crews do for BIG, temporary electric heaters. This could work for your 60 Amp EVSE, but I decided that for the few times I would need it, and the difficulty in convincing RV park owners that I was competent with electrical stuff, it just was not worth it.

    I add to the chorus that you should NEVER try to take more than 40 Amps from an RV Park 14-50. Even if they do have circuit breakers, it can be an embarrassing hassle to find someone to give you access to the breaker. Besides doing this would probably give the rest of us EV nomads a bad name.
     
  8. David99

    David99 Active Member

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    Agreed! Let's not cause problems at RV parks. They might get annoyed and won't let EVs charge any more.
     
  9. qwk

    qwk Model S P2681

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    I have thought about that as well, but in the majority of cases it wouldn't work because of the fact that the breakers are really in a dedicated site sub-panel next to the outlets. The feed for these is likely too small for much over 40A continuous (for all of the outlets combined). Couple that with the need to tear into the panel, and the likelihood of RV park employees or owners rejecting the idea, and you end up with a bunch of wasted time, and possibly an alienated RV park to future charging.
     
  10. Brightonuk

    Brightonuk Member

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    I took these shots at Homestead Speedway they have 20+ hooks ups for motor homes.
    I had the adaptor for the 3 pin and successfully charged at 40 amps.
    The four pin outlet shows 50 amps and the breakers are 50 amps X 2 and 100 Amps

    This seems ideal for a juice box

    Homestead Socket 2.jpg
     
  11. FlasherZ

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

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    The 100A breaker is likely a "main" for that box - some local codes are more strict than the 6-handle disconnect rule and require a main breaker for subpanels. So the 100A on the right is the feeder to the box, then the 50A/240V breaker (double-pole or your "50A x 2" is for the left receptacle, the two breakers in the center are a 20A/120V breaker for the NEMA 5-20 and a 30A/120V breaker for the TT-30.

    - - - Updated - - -

    Taking open someone else's panel is generally a bad thing to do, because of liability concerns and the fact it can get you kicked out. The staff managing campgrounds rarely have the level of knowledge needed to give you permission, so that even when they do give you permission, when the engineering team finds out they will generally get pissed off at you as well. Even with my knowledge, I don't go mucking about inside someone else's panels without permission. I do troubleshoot with my meter to find problems (like the campground that fed a NEMA 14-50 with a single ungrounded leg so that you got 120V from neutral to L1 and neutral to L2 but 0V from L1-L2), and I then go back to the office and ask to speak with engineering if they're available.
     
  12. AmpedRealtor

    AmpedRealtor Active Member

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    You're playing with fire.
     
  13. Cosmacelf

    Cosmacelf Active Member

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    You charged at 40a from that 3 pin??? That's a TT-30 which maxes out at 30a (120v). I guess their breaker was faulty. Good thing the wires didn't melt.
     
  14. Brightonuk

    Brightonuk Member

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    actually the first one stopped charging after about 10 minutes so I plugged in the on the opposite side and that charged for over an hour I did feel the plug and wire and they were warm but not overly hot.
    I thought the one on the right was 240v? would I be better off getting a TESLA PN: 1014324-00-adaptor as I think that fits four pin outlet?
     
  15. FlasherZ

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

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    No, the receptacle on the right is a TT-30, rated 120V/30A.
     
  16. Cosmacelf

    Cosmacelf Active Member

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    The one on the left is a NEMA 14-50, supplies 50A at 240v. Yes, that part number is the correct Tesla adapter. It comes standard with the car, so you usually don't have to buy it.

    The one on the right is a TT-30, supplies 120v at 30A. Presumably you used a third party adapter to plug into it? What did you use?

    Honestly, you really need to understand what you are plugging into when you use third party adapters as the UMC doesn't know what the circuit capabilities are when a third party adapter is used. The problem is that the wires behind the panel could be overheating and causing a fire if you try to draw more than the rated breaker rating. As you found out, breakers don't always trip when the current exceeds their rating.
     
  17. FlasherZ

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

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    I suggest reading the resources available for circuit breakers and how they work. Many people believe that circuit breakers trip immediately when you exceed their rating, e.g. at 30.0001A on a 30A breaker. This isn't the case; while most circuit breakers will trip immediately on a short-circuit, if the current exceeds the rating only slightly, it may take hours to trip.

    UL 489 specifies that circuit breakers must hold on at 100% of current rating, trip within one hour at 135% of rated current (<=50A) or two hours (>50A), and trip within 2 minutes at 200% of current rating (<30A). As a result, it may take a while for a breaker to trip, meanwhile you're overloading conductors and heating them up pretty seriously.
     
  18. Kandiru

    Kandiru Member

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    Guys, although only certified as an electrician in Bulgaria, I can tell that some of the ideas voiced on this thread are plain dangerous.

    IMHO safer to upgrade to dual chargers, get a HPWC or JuiceBox for home if wired for 100A with 4 or preferably 2 AWG shielded wiring and breaker boxes, on a 200A main breaker or above as you will have air conditioners, ranges, dryers, etc to compete with.

    I suspect the JuiceBox as opposed to the Tesla HPWC is not as smart, ie it will not limit current flow if the RV Nema 14-50 only supplies 30A, so a fire may start if breakers don't kick out first, have this happen twice and the gas-guzzler $800/tank RV grandpas will demand an EV ban.
     
  19. ChrisPDX

    ChrisPDX Member

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    Actually, the JuiceBox is just like a HPWC in that you can set current limits. There's a trim pot on it that you adjust which modifies the max current signal. It's even covered in the assembly directions, but admittedly they kind of just quickly mention it. I was a bit disappointed in the directions in that nowhere does it mention you should set the current limit to either what the J1172 cable can handle or 80% of the circuit you are connected to (whichever is lowest). I'm sure there are plenty of JuiceBox users are have theirs setup to the default 30 amps with it plugged into a 30 amp outlet.

    As for me, I got one to charge our Fiat 500e. Currently on a 30 amp circuit with it set to 24 amps. No problems and it works great. Was a big cost savings compared to other J1772 options. Also good to know I have a backup should something happen to my UMC.
     

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