Dumb New Electrical Code Could Doom Most Common EV Charging (motortrend.com) 39
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.)
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.)
Clarifying the problem (Score:1)
If I understand the problem correctly, the charger is considered the "equipment", so there would need to be a GFCI between it and the panel (or as part of the panel breaker itself). Assuming the charger is hardwired to the building, does code allow it to have its own integral GFCI rather than somewhere in the homerun before it? Having GFCI in the locked basement is not specific to chargers, or to anything really...just a poor usability design, and that's not The Code's problem.
On the other hand, if the new
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I think the problem is more along the lines that outside of the lab, GFCI breakers tend to be a bit squirrely and trip when they shouldn't.
I don't have my EV chargers on a GFCI circuit, electrical code be damned. Both the vehicles and the EVSEs have their own monitoring circuitry to make sure everything is kosher before allowing power to flow, and there is literally no conductive surface on the EVSEs to present any sort of a shock hazard. This is just the code people being overly cautious.
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does code allow it to have its own integral GFCI rather than somewhere in the homerun before it?
The EV chargers have their own integral GFCI. The code doesn't care that they have an integral protector and is adding the requirement of an additional GFCI on the 240 V outlet being provided for a charger.
Any additional GFCI on the circuit is subject to frequent nuisance tripping when connected to a charger. Among other things an EV Charger performs a number of tests that ground is functioning between th
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This is a tempest in a teapot because correctly designed electronics don't use the ground plane as a current source or sink during normal operation.
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I plug my Prius Prime into a GFCI outlet because it's in the garage and they've been required there for a long long time. There has never been a problem, and I don't see offhand why there would be a difference between Level 1 and Level 2.
Did I misunderstand the fine article? Was it saying that EVSEs might have ground faults more than 5 mA? Uh, how? With, as you pointed out, their own protective equipment on board.
Re: Clarifying the problem (Score:2)
The problem is with slow chargers, which often plug into a standard 240V outlet. I charge my car using one. But I also have my whole system on RCDs (AFAICT this is the European name for what's being required?) and don't have a problem.
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Here in the UK, when I put my home charger in about nine years ago, it was required to be on an isolator and thus separated from the house’s RCD. That was a safety requirement, but now I think about it, it also avoided tripping the RCD. The US so often does such shitty implementations of things. Like hotel rooms that are too dark and have bathtubs that are too shallow with horrible shower curtains that suck inwards towards your body when the water goes on.
Re: Clarifying the problem (Score:2)
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There's an exemption? (Score:1)
From the fine article:
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.
What does it take to have a bi-directional EVSE? I assume it's more involved than the typical uni-directional kind. If the nuisance trips are a problem and there's an exemption then I expect the exemption will be popular unless the cost is prohibitive.
This sounds like a few good reasons to have a PHEV than a BEV. If the EVSE trips the GFCI in the middle of the night then your overnight charge might not be enough for your trip the next day. If there's an extended power outage becaus
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This sounds like a few good reasons to have a PHEV than a BEV. If the EVSE trips the GFCI in the middle of the night then your overnight charge might not be enough for your trip the next day.
Since getting it a bit over a year ago, my partner's EV has experienced failed overnight charging twice. The first time was due to a crappy no-name charger from Amazon giving up the ghost, and the second time was due the utility transformer blowing. Both times, a half hour of charging at the nearest DCFC station took care of the problem. It's rather hilarious to think that's a potential dealbreaker for EV ownership, when with an ICE vehicle you literally have to make a trip to the gas station every singl
Re: There's an exemption? (Score:1)
I'm glad that you were able to overcome your failed overnight charging situation with a nearby DC fast charger. Not everyone has the luxury of such a facility within a reasonable distance of their home or in the direction of their planned travels. Or have the unplanned extra 30-60 minutes to spare when they're traveling on a schedule.
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Well, I’ve been charging at home for nearly a decade, and have never not once in all those years had a failed charge. But then, I’m in the UK where we have a resilient grid and sane power infrastructure
well potus Musk will make short work of this (Score:1)
Lameness filter encountered. Post aborted!
Filter error: You can type more than that for your comment.
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After seeing his recent antics, I'm not sure Leon truly cares if his company ever sells another car. I used to wonder what the hell was up with him opposing the EV tax credits, but then he goes and does a damn Sieg Heil salute and it's clear he's in 100% DGAF mode. It'd be completely on brand for him to say this GFCI thing is a great idea because it means people will just take their EVs to a Supercharger rather than charge them at home.
Then ya'll will be like "I did Nazi that one coming."
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Tesla was the first one to run out of EV tax credits. That's because Tesla is the biggest EV car manufacturer in the US market and those tax credits are capped based on the number of units sold. In other words, those tax credits were mostly helping his smaller competitors, not Tesla.
As to the rest of his antics, I can't really explain them either.
Is this article about US or European regulations? (Score:2)
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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.
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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-
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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.
Why are they complaining? (Score:2)
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.
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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.
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If the GFCI is TOO touchy, it may trigger even where there is not actually a ground fault (AKA a nuisance trip).
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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.
Protecting People, not Equipment (Score:2)
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.
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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
Japan (Score:2)
Japan doesn't have electric cars because GFCI is mandatory. Ever noticed when you go to Japan you never see any three prong outlets there? There's no such thing as a three prong plug in Japan because GFCI is mandatory.
Equipment manufacturers use NFPA to make money (Score:1)
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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.
Association, not Agency! (Score:2)
That's how you know it's not a federal authority doing this
It is, in fact, a government regulation (Score:2)
It is, in fact, a government regulation because its referenced by name, edition, chapter, etc. in many states building codes.
Is this only relevant for plug-in vs hardwired? (Score:2)
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.
An USA thing? (Score:2)
When the author says "That's because it proposes to require the same exact ground-fault circuit-i