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Transportation Power

Dumb New Electrical Code Could Doom Most Common EV Charging (motortrend.com) 141

Posted by BeauHD from the timeline-to-trouble dept.
Longtime Slashdot reader schwit1 shares a report from MotorTrend: A coming ground-fault circuit-interrupter revision could make slow-charging your car nearly impossible. The National Fire Protection Agency (NFPA) publishes a new National Electric Code every three years, and we almost never notice or care. But the next one, NFPA 70 2026, has the Society of Automotive Engineers (SAE) electric-vehicle charging subcommittee, OEMs, and companies in the EV Supply Equipment (EVSE, or charger) biz mightily concerned. That's because it proposes to require the same exact ground-fault circuit-interrupter protection that makes you push that little button on your bathroom outlet every time the curling iron won't heat up. Only now, that reset button will often be down in an electric panel, maybe locked in a room where you can't reset it. If EV drivers can't reliably plug in and expect their cars to charge overnight at home or while at work, those cars will become far less practical. [...]

The national code doesn't care what you're plugging in, but vehicle chargers deserve their own carve-out. That's because no current ever flows until the charger has verified a solid ground connection from car to charger and from charger to electrical panel. They also include their own GFPE (Ground Fault Protection of Equipment), which is intended to protect equipment and is permitted to trip at values larger than 5mA, often in the 15-20mA range. That's why this new code REALLY needs to set a higher supply-side cutout (like what is allowed for marine vehicle shore power, which is up to 30mA). Because even if the Special Purpose GFCI with its 15-20mA trip level were allowed, it would be a 50/50 chance that any fault would trip the electrical-supply breaker or the device's internal breaker. But while the device is programmed to automatically reset and try again, the panel requires a manual reset. There is one EV-charger carve-out: Bi-directional chargers are exempt.

This problematic application of 5 mA trip to most 240-volt equipment was added into this regulation late, during a second draft, and now the only way to head it off is for interested parties (SAE, OEMs, and EVSE manufacturers) to register their notice of motion in February for consideration in March. This isn't a government regulation, so it's utterly unaffected by the change in federal administration. These are functionary folks with minimal experience of EV charging, so the arguments must aim to convince the NFPA that implementing this code as is could grossly embarrass the Agency. (Understanding that any such embarrassment will only arise after buildings and projects are completed under the new code.)

Dumb New Electrical Code Could Doom Most Common EV Charging More | Reply

Dumb New Electrical Code Could Doom Most Common EV Charging

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  • The article mixes 240 and 120 V freely, making me doubt the author (I refuse to call him journalist) knows what he's writing about. It's way too common these days. :-(

    • Re:Is this article about US or European regulation (Score:5, Informative)

      by viperidaenz ( 2515578 ) on Friday January 24, 2025 @01:18AM (#65114291)

      240V is common for garage car charging in USA.
      This has nothing to do with EU, as they don't care what the NFPA say.

      Maybe you're unaware that USA homes are supplied with a centre tapped 240V supply. Half the house is supplied from each half, with some appliances like dryers getting the full 240V.

    • It used to be that only general purpose 120V, 15 and 20A outlets requried GFCIs-- equipment that would be plugged in and unplugged within the vicinity of a tub or sink. Then they decided every 120V outlet in a "wet location" should be GFCI, including things like the refrigerator. Same held for outlets installed outside. Garages and carports followed a similar path, eventually everything needing to be GFCI.

      I forget if it was the 2020 or 2023 code cycle where they added 240V outlets, and eliminated the 15-

      • The problem with this is that the availability of 240V GFCI breakers and outlets is still extremely poor, and you can add around $100 to the cost of install.

        In my area the county actually posted an errata removing the requirement for HVAC systems to be on GFCI due to problems getting breakers and nuisance tripping.

        My brother's an electrician, he keeps me up to date on this stuff.

      • And I still don't see why this is a problem. Early GFCIs were within the outlets and served multiple outlets. So when a GFCI tripped and an outlet didn't work, you had to remember which one was linked and go reset. If that didn't work, you went to the breaker box. Things are different now. If an outlet doesn't work, you go to the breaker box and flip either the breaker or the GFCI and you're back in business.

        • The problem is two-fold: people should not go willy-nilly resetting circuit breakers firstly, and secondly people might not always have access to the breaker when it trips-- think of a circuit on a house panel in an apartment complex.

          There is also the issue that it is completely unnecessary. The purpose is to address poor installation, specifically improper grounding. There are significantly more serious problems if you start to assume the electrical installation is not done properly. AFCI and the expansion

          • If installing a charger in a place where the customer doesn't have access to the box, it's even more important to have a local GFCI and breaker. If you have local protection circuits that are *faster* than the box circuits, you won't ever trip the circuits in the box (unless they are terribly faulty). That's why all audio equipment tends to have fuses or breakers that will trip before the outlet breaker. It's the same principle. The worst case is a braker box with GFCI and none on the charger. Now ther

    • making me doubt the author (I refuse to call him journalist)

      So because of *your* ignorance you dismiss and insult someone else? 240V is common in the USA for fixed appliances and high current devices (look up split-phase power).

      And when you're done educating yourself try and be less of an arse.

  • If there's a ground fault, fix the ground fault. Don't keep trying it again.

    Auto-resetting a ground fault protection seems like a dangerous feature.

    • 5mA is over-sensitive, as it can occur in perfectly safe situations when charging cars outdoors. The auto reset is so that if a transient fault occurs, the car can continue to charge, without human intervention.

    • Re: (Score:3)

      by evanh ( 627108 )

      They're wanting the more reasonable 30 mA trip level. And I'd concur, we use 30 mA where I live and it works great. 5 mA is reserved for medical environments.

    • Re: (Score:2)

      by sjames ( 1099 )

      If the GFCI is TOO touchy, it may trigger even where there is not actually a ground fault (AKA a nuisance trip).

      • Re:Why are they complaining? (Score:4, Insightful)

        by Firethorn ( 177587 ) on Friday January 24, 2025 @04:01AM (#65114503) Homepage Journal

        And too many nuisance trips is how you end up with no GFCI protection at all, as the homeowner removes that annoying thing, and if you're lucky, puts in a regular breaker. It's like $100 less than the GFCI one, after all.

        If you go back to the fuse days, too many burnt out fuses risked having a penny installed instead.

      • If the GFCI is "too touchy" then it is faulty and not tripping at the correct level. If it is tripping anyway then you have a ground fault somewhere that is around the level of the safe touch current and you need to fix the ground fault somewhere.

        There's no such thing as a nuisance trip. There are only faults in your home be they wiring, devices, or electrical design.

        • This. I learned this long before I became an electrician, when I struggled with crashing software and installed Norton Crashguard, which basically ignored crashes and let the all continue running, often with amusing results. Ignoring the bug/crash is no solution, and auto restarting software after it crashes is a horrible kludge.

          The same applies to electrical faults.

          Does US have different type of GFCI? In Europe we've got various types with different capabilities:

          Type AC: only good for sinusoidal AC
          Type A:

          • Re: (Score:2)

            by flink ( 18449 )

            The point of an outlet is they are modular. You can plug any kind of load into it as long as it doesn't exceed the current rating. Having to know exactly what kind of breaker happens to be attached to it kind of defeats the purpose for the average home owner, don't you think?

        • Re: (Score:2)

          by sjames ( 1099 )

          That is only true in a purely resistive load (which a charger is not). It is possible to spec a GFCI device such that the nuisance trips don't happen, but that runs afoul of regulations with a one size fits all approach that won't carve out exceptions. It tends to be a problem when people assUme that if some is good, more is more gooder.

  • They also include their own GFPE (Ground Fault Protection of Equipment), which is intended to protect equipment

    I suspect the code is more worried about people, thus the lower threshold for tripping. This is a building code and they may not be willing to assume all the equipment on the circuit will always have adequate protection for people.

    • Re: (Score:2)

      by mysidia ( 191772 )

      I suspect the code is more worried about people, thus the lower threshold for tripping.

      It is not merely that code is more worried about people.. The code authors literally do not care in the slightest about anything else and are concerned solely with requiring all measures they can get away with implementing to assure maximum safety. They don't care much about costs or practicality - the code authors have been known to mandate very expensive requirements such as the new requirements for specialized comb

  • NFPA code is overly driven by device manufacturers who want to sell expensive devices. The code regularly drives up to the cost of new homes. Some reasonable states have pushed back and exempted some of the nonsense. For example: AFCI breakers - they are very expensive, unreliable, and cause nuisance trips. I know at least one state the stepped up and said AFCI was not required. If we are serious about lowering the cost of housing, there need to be reasonable cost trade-offs. Adding $1000 to the cost

    • I've even read that AFCI breakers are designed, not to save lives, but to save property, by preventing fires.
      That said, when the math was done, the increased cost of AFCI breakers, up against prevented damage, only makes sense in a home with over a million dollar replacement cost.

    • Adding $1000 to the cost of every new home must be offset by how many homes/lives it will actually save.

      Given AFCIs are designed to prevent your house from burning down, the cost of literally thousands of AFCIs is covered if only one house doesn't catch fire.

      Also where do you get the $1000 from? An AFCI is $30. Likewise an RCDO is only a couple of dollars more expensive than a simple OCB.

      Do you value your life / property so little?

  • That's how you know it's not a federal authority doing this

  • It is, in fact, a government regulation because its referenced by name, edition, chapter, etc. in many states building codes.

  • A few posts have intimated that this requirement is just for chargers plugged into outlets, rather than a proper hard-wired wall box. Is that right? In the UK, we call those “granny chargers” and they’re not recommended for anything other than occasional charging.

  • Having trouble getting my head around what the issue is. I'm in New Zealand and when I installed a Tesla Level 2 charger 5 years ago the big cost was the RCD with DC leakage sensing. I'm guessing they will be cheaper now BEVs are common. That RCD went at the switch board. In the 5 years I have been using it it has never tripped. It would seem to me that if yours is tripping you are doing something wrong.

    When the author says "That's because it proposes to require the same exact ground-fault circuit-i
    • In the USA, GFI's are common in bathrooms and near sinks, mostly, I think, in case an appliance gets wet or falls into the water. But, in my experience, the GFI goes off once every 3 months or so for no apparent reason, and the simple fix is to hit the reset button.

  • Is this word helpful here?

    Clearly, this is a matter of opinion, as some experts (you know, the ones updating the rules--these people aren't sanitation workers) think it's a good idea. Perhaps a discussion is more appropriate. Calling it "dumb" only makes the author look...dumb.

  • This is just regulation designed to make something so useless it won't get adopted. For example: arc supression breakers are required for new construction. However if you happen to enjoy vintage equipment you're fucked; because the first time a brush motor or contact point arcs it trips. As a pinball technician this was a major problem...those things will arc just during normal operation.

    This is the same thing. By adding safety but reducing usability; two things will happen: people stop using it, or so man

  • These are the clowns that brought us mandatory ARC fault breakers, promulgated absurd requirements for low voltage wiring, tagged on thousands in additional costs to solar installations without credible objective evidence of efficacy and complete disregard for the interests and safety of those other than themselves.

    For example the requirements for per module electronics in a PV install has not only significantly raised the material cost of installation it raises maintenance costs of replacing large numbers

  • Gets modified by cities and states all of the time. A city or state can choose not to implement a specific section, or add sections which are contrary to the national version. This is what I think will happen, if it this rule is finalized.

    • So much this. It's usually adopted by reference, and that reference is to a specific version. It's not like municipalities are doing apt get upgrade every time there's a new NEC release.

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