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Got myself confused re AC charging

Discussion in 'The UK and Ireland' started by thegruf, Aug 10, 2018.

  1. thegruf

    thegruf Active Member

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    In the UK, so 230/400V
    assuming the current capacity is available from the supply, what is the maximum that a faclelift MS charger can take single phase/3 phase.
    Also what is the HPWC cpable of single and 3 phase if this is different.
     
  2. cezdoc

    cezdoc Member

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    I believe the on-board charger on the facelift cars is able to take up to 16.5 kW. Single phase I think it's the same as my pre-facelift, non-dual charger car which is 7kW. I think the exact power is related to current so the power numbers depend a bit on the supply voltage.

    16.5kW ~= 24A 3 phase (16.6kW @ 230V or 17.3kW @ 240V)
    7kW ~= 32A 1 phase (7.4kW @ 230V or 7.7kW @ 240V)

    I see 16A 3 phase with my 11kW charger; in my experience 3 phase public supplies are on the high side voltage-wise so I get about 11.5 kW which is a very useful 50% fill-up in 3 hours (for my 70 kWh battery).

    If HPWC = UMC I've only used it on single phase supplies in which case it can deliver 32A single phase using the blue commando connector. Again exact power depends on voltage; I get about 7.2 kW at home.
     
    • Informative x 1
  3. arg

    arg Supporting Member

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    HPWC can go up to 32A per phase, so matches/exceeds the capability of all Model S (assuming you haven't dialed it down due to lack of capacity at the site). So nominally 22kW three phase, 7.3kW single phase, slightly higher/lower if the mains voltage is high/low at your location. 24.3kW at the UK maximum legal mains voltage.

    Facelift cars are limited to 32A single phase(*), 24A three-phase, so nominally 7.3kW single phase, 16.6kW three-phase. Originally there was a power limit as well as the current limit (so if the voltage went up you didn't get more power), however recent reports say that's no longer the case.

    (*) I have not heard anybody actually confirm experimentally what the behaviour is on high current single-phase supplies. Definitely on three-phase it limits at 24A (if you have a 62A-capable chargepoint like many rapids, it will draw 24A). So there's an outside possibility that if you built a >32A single phase chargepoint it would do something interesting. Pre-facelift cars definitely don't.
     
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  4. thegruf

    thegruf Active Member

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    thanks folks. It was the fact tha tthe HPWC can do 32A/ph that had me wondering if I had missed something and the FL cars could take this. Sadly not it seems.
     
  5. Asterix187

    Asterix187 Member

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    I get 18kW on 3 phase from every connector I have ever plugged it into.
     
  6. Subevo

    Subevo Member

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    18kw for 2017 model s
     
  7. thegruf

    thegruf Active Member

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    so 18KW = appx 26A/ph @400V - slightly beats the nominal 24A/ph then.
    thanks all.
     
  8. arg

    arg Supporting Member

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    More likely 24A/phase at 243V or greater (= 17.5kW, and the display in the car rounds to the nearest kW).
     
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  9. thegruf

    thegruf Active Member

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    Okay a bit more ...

    The UMC does 32A Single phase, but 3 phase only 16A/ph.
    So for 3 phase from a red 32A commando I am capped at 16A/ph, ie two thirds of what the car can take.

    This seems like an oversight in the UMC design from the earlier cars that can only take 16A/phase single or 3 phase, the UMC should have been updated to be in line with the later car's charger capability.

    What is the most economical way to get to 24-26A/ph for 32A Red Commando?
    I really dont want to shell out a few hundred quid on yet another cable, is there such a thing as an adpater for the included blue type 2 cable, or an easier way to do this?

    Reason I am asking is that I have a Red 32A commando at my factory that I can make use of, but really dont (at this time) want to put in a charge point for a number of reasons
     
  10. arg

    arg Supporting Member

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    Actually, the earlier cars had 32A/phase capability (with the dual charger option, which many people bought in the days before CHAdeMO). When the facelift cars appeared, the base option was still 16A (via software limit if you hadn't paid for the higher capacity).

    The UMC I think was largely aimed at home charging, where 16A was the largest likely to be affordable (and in many parts of Europe, capacity 32A single phase was unlikely to be available in homes).

    The UMC has never had an official means to use a 32A red socket. You can make up the obvious adapter cable with questionable legitimacy (I'd be happy with it myself), or obtain housings with a 16A breaker in it for belts-and-braces. Of perhaps greater concern is that existing industrial sockets may not have any RCD protection.

    There's no really good solution to your problem - the cheapest way forward is probably to put a flying lead and plug on a HPWC, but that's still a fair cost.

    There's no meaning to an "adapter" for your type2 cable, as that doesn't have the electronics and contactor in it - the "adapter" would be a complete chargepoint. UMC's contactor is limited to 16A (32A on the neutral) - with the blue adapter it gets 32A by paralleling two of the phase pins.
     
  11. thegruf

    thegruf Active Member

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    @arg - thanks for putting me straight on this.
    It's kinda as I knew really but just wanted to go through it all again in case I missed something.

    Seems dumb that you can't just rock up to a 32A Red Commando and suck it dry.

    The idea of an HPWC lobbed in the boot with a flying lead is just too funny - bizarrely though it might just be the way to do this, and fix it to the factory wall at some point in the future! Cheap HPWC going anyone?
     
  12. GeorgeSymonds

    GeorgeSymonds Member

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    You can buy an aftermarket equivalent to the UMC that does 3 phase 32A - google Juice Booster 2 although its not cheap.
     
  13. thegruf

    thegruf Active Member

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    Thanks @GeorgeSymonds - that's the problem really - this price of some of this stuff is silly.
    The incremental cost for Tesla to have made the UMC 32A would be tiny, maybe $10, but I guess re-tooling for limited damand is the bigger issue.

    As @arg says grabbing an HPWC and putting a flex lead on it bizarrely may be the best option, at least it can be screwed to a wall or readily sold on later, just a bit cumbersome.
     

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