3 Phase Home EV Charger Outputting Single Phase Wattage

Lqaryab on 11/06/2023 - 12:33
Last edited 13/06/2023 - 19:51

Hey everyone,

I recently installed a home electric vehicle (EV) charger, and my house has a 3-phase circuitry, and the ev charger is not providing the expected charging output. I'm hoping to get some insights and advice from the community here.

Here are the details of my setup:

  • I have a 240-volt x 3 phase and Tesla wall charger gen 3.
  • The charger is connected to a dedicated circuit in my home's electrical panel.
  • I verified that the circuit breaker is rated for the charger's amperage.
  • Fully qualified electrician installed the ev charger (however, my gut feeling telling me that he stuffed up the grounding of the ev charger unit).
    I have a BYD Atto 3, current year model.

The issue I'm facing is that the charger seems to be delivering a lower charging output than it should. For example, the charger is rated for 32 amps, but I'm only getting around between 6~7 kw during the charging session. This results in slower charging times than I expected.

I attached a screenshot of the installation page on the Tesla wall charge Gen 3 here https://imgur.com/a/vlNW9u9 and I would like if anyone has a similar setup and what output figures they are getting from their ev charger? TIA

I'm wondering if anyone has experienced a similar issue or has any ideas on what might be causing the lower charging output. Could it be an issue with the charger itself? Is there anything else I should check or test to troubleshoot this problem?

Any advice or suggestions would be greatly appreciated. Thank you in advance for your help!
Concerned EV Owner

12/06 update: screenshot of the BYD Atto 3 charging https://imgur.com/a/I1s2cOX

Automotive Electric Vehicle Charger

Comments

  • justdigi on 11/06/2023 - 12:50

    Isn’t the limitation at the car end in that case? What is the AC max for the car?

    • GordonD on 11/06/2023 - 13:54
      +1

      BYD Atto 3 max charging rate:
      DC: 89 kW (370 km/h)
      AC: 7.4 kW (34 km/h)

      • Bigboomboom on 14/06/2023 - 14:34

        In reality it's capped at 6.5kW. The Atto 3 tends to pull 1-3A less than max rated.

  • galtaforce on 11/06/2023 - 12:53
    -1

    Atto 3 only supports 7kW AC charging. 6A x 230V x 3 phases still only 4kW though. Have you confirmed your wall connector wired for three phases or does it just have a single pole breaker?

    Edit: just looked at the screen shot. Looks like it’s only showing single phase wiring although I can’t remember if there’s a further screen showing other phase voltages. You can get a 3rd party app such as Tesla Wall Monitor and check currents on each phase while charging.

    • Euphemistic on 11/06/2023 - 18:46
      -2

      6A x 230V x 3 phases still only 4kW

      Don’t think that’s how it works. 3 phase is usually 415v.

      • Switchblade88 on 11/06/2023 - 19:08
        +3

        Not exactly, no. 415v is the calculated output between any two of three phases in terms of electric potential. Each phase is still 230v potential to neutral.

        For a battery charger, each phase is essentially parallel charging the batteries via a switched-mode power supply converting to DC, so the input voltage is not as important as say a 3-phase motor driving an industrial machine.

  • JTTheMan on 11/06/2023 - 14:06

    Can't speak for the BYD charger but I have a gut feeling that your gut feeling is correct and that there is a problem with the install.

    Your house has 3 phases and the Tesla wall connector is 3 phase so the charging should be using all 3 phases if installed correctly.

  • AndyC1 on 11/06/2023 - 14:48

    Check that is is 240V as three phase is 415V between the phases. The phases are 120' out where the max voltage is 415v. The attached doc is a for a single phase as gnd an neutral will be what is shown for one of the phases. I would also point out that you may have a bad or dodgy earth in the house due to the 2.9V, but I am not a qualified sparkey.

    Have a very close look at the circuit breaker and see if it is a single phase or three phase circuit breaker by looking up the specs and see what it is.

    I would also lookup the charger model number on the charger and see if it is a 3 phase or single phase charger. If it is a 3 phase charger, then download the install instructions and see if it can be installed on a single phase circuit and see if this is the way it was installed.

  • JimmyF on 11/06/2023 - 15:13
    +5

    I have a BYD Atto 3, current year model.

    That'll do it…. BYD is limited to 7kw AC charging.

  • UnternamenBernhard on 11/06/2023 - 15:41
    +1

    One option not mentioned- garage the car in a rural area- these usually have three phase mainline for agricultural and light industrial equipment.

    • Gunnar on 11/06/2023 - 23:34

      Came here to see a ‘buy a petrol car’ comment but this is way better!

  • redfox1200 on 11/06/2023 - 17:51
    +1

    installed by an "electrician"

  • brendanm on 11/06/2023 - 18:11

    Your screenshot shows only a single phase connected, L1.

  • HeXo on 11/06/2023 - 20:16
    +5

    Electrician here. There is a bit of misinformation in this thread.

    Your charger is connected to a single phase supply, not 3 phase. To utilise 3 phases, you need your electrician to connect the charger in 3ph delta. This will make it a balanced load and you should see 400v across each phase once this is done. In this case, there would be no neutral connected.

    If the charger is installed correctly, your theoretical max output would be: 32x400 square root (3). This would give you 22ish kW to charge your EV. This is assuming that your EV supports 22kW charging from an AC source.

    It sounds like either your electrician has not understood what work you wanted.

    • GordonD on 12/06/2023 - 16:27
      -7

      Not an electrician here. But I do know that you don't want 415V in a house. Domestic equipment doesn't run on 415V. It runs on 240V. You want three 240V phases.

      • HeXo on 12/06/2023 - 16:51
        +2

        I can tell you aren't an electrician, because your reply makes no sense. Not even going to bother correcting you.

        • GordonD on 13/06/2023 - 10:12
          -2

          No, I'm not an electrician, I'm an engineer.

          If I'm so wrong how do you get 240VAC for all the 240VAC equipment in domestic premises from a 3 phase supply? Houses with a 3 phase supply don't ALSO have a single phase 240V supply. The 240V everything uses in a home comes from the 3 phase supply by star connecting it rather than delta connecting it.

          The voltage between line conductors is 415VAC. The voltage between each line conductor and neutral is 240VAC.

          • HeXo on 13/06/2023 - 10:19
            +2

            @GordonD: 1) Australia is 230V, not 240
            2) Australia is 400V, not 415
            3) It's not that "you don't want" 415v in a house. It is that most household appliances run on 230v. 3 phase supplies exist as an option for people that need to run appliances on higher voltage, for which many cases exist. Car chargers, kilns, ovens, etc.
            4) "You want 3 240v phases" makes no sense. You either have a 3 phase supply, or you don't. As you have said in your most recent comment, the presence of 230v or 400v depends on how you connect the supply.

            So overall, I'm not actually sure you know what you're talking about, and I'm also quite sure you're not an engineer as you learn the above in year 2 of trade school.

      • Euphemistic on 12/06/2023 - 18:29

        Yeah, that’s not how it works.

      • bhubb18 on 13/06/2023 - 09:47

        Not sure why you bothered commenting when you have 0 idea what you're talking about

  • Vendarite on 12/06/2023 - 10:47

    If you haven't done so yet check the dip switches and check they are set correctly this happened to me once I set the dip switches it charged at the correct rate

  • Frost2468 on 13/06/2023 - 09:34

    Even if it's jist a single phase it would still try and pull the 32A through it as you have shown in the charger settings. I would be looking at the car settings as to what is limiting it.
    There is no current monitoring on your main supply with the gen 3 charger which is why you have to be careful with maximum demands.

    • Frost2468 on 13/06/2023 - 12:46

      After finally looking at your car charging pic, that says 6.5kW not Amps. What was the problem?

  • frenzaltom on 13/06/2023 - 22:28

    Picture of your electrical switchboard would help

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