> … 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.

Specifically if your GFCI in the bathroom (or anywhere) keeps tripping it’s because something is wrong with your wiring or something plugged into the outlet.

It took some restraint to not use all caps in part of that sentence.

Unfortunately this is not quite true. For two-prong plugs, yes, it is 100% accurate. However larger devices with grounded plugs, especially heavier machinery, will typically contain a line filter with Y capacitors running line to ground. This shows up as a tiny leakage current, which some GFCIs will detect (because it really is leaking) even though this is a nuisance trip (because it is completely safe and normal operation). That's part of where the 30mA trip specification for certain types of non-normal-residential-circuit comes from.

edit: 120V is not immune. I once worked on a project involving powering equipment in a Faraday case at 120V. The mandatory filter (to prevent the wire from conducting emissions out of the cage) instantly tripped GFCI.

The right solution IMO would have been one of:

a) A better filter that doesn’t pass 50-60Hz. This is doable in theory, but I’ve never seen one.

b) A transformer or other isolated supply outside the cage, with a GFCI inside the cage (to protect the people who may enter to touch the equipment).

c) A transformer outside, not necessarily right next to the cage, supplying the inside with two opposite-phase lines at 60Vrms each. No net leakage! This would require that everything inside accept such a supply, which rules out anything that wants a real neutral.

d) I bet someone could design a transformer with a shield between the windings that would integrate with the Faraday cage. Power would couple in inductively through the shield. Common-mode RFI would have a very hard time escaping, and different mode RFI could be filtered and probably matters quite a bit less anyway.

Of course, the actual solution chosen by the site’s electrical people was rather less classy.

Of course, real transformers are not ideal. This:

> I bet someone could design a transformer with a shield between the windings that would integrate with the Faraday cage. Power would couple in inductively through the shield. Common-mode RFI would have a very hard time escaping, and different mode RFI could be filtered and probably matters quite a bit less anyway.

exists and it is called an "electrostatic shield" inside a transformer. Magnetics people do not like to make these, but they are a standard enough request that they'll do it for you and the only complaints you'll get will be from the people on your side who see the invoice. Electrostatic shields are also not perfect but they help tremendously. The shield connection usually comes out of the potted assembly on another wire so you can hook it up as required.

Protip: if you are ever trying to replace or redesign equipment that uses an electrostatically shielded transformer, do ask why they went to that effort. Don't just try to use a normal transformer and then wonder why you can't get it working right... despite man-months of effort....

Yes and no. You declare one of the secondary wires to be neutral and the other to be the “line”, and you connect “ground” to “neutral” in exactly one place. And the GFI monitors the sum of the line and neutral current, but not the ground. And you connect your equipment chassis to ground via the wire that, in the US, is green and is called, in the NEC, the “equipment grounding conductor”. And the GFCI will protect you if you are touching a grounded object with one part of your body and accidentally contact something that’s is at “line” voltage.

If you are using a transformer to provide power to part of a building subject to the NEC, you may be required to do approximately this. And your bathroom receptacles are hopefully GFCI protected and are also fed from a transformer near your house…

> electrostatic shield

You can get a transformer with approximately this, in small sizes, sold for “medical” use, off the shelf at reasonable prices. I have one that I bought from Digikey because it had the right specs, even though I don’t need the shield.

But I haven’t seen one that has fittings intended to integrate it into a Faraday cage. Maybe someone makes it. Admittedly, I have not worked with that many Faraday cages in my life, and I didn’t get to examine the detailed construction of the giant anechoic Faraday cage in which we tested the smaller Faraday cage I was using.

The NEC might or might not have something silly to say about that, but when you have a giant custom-built Faraday cage, I think most people will be understanding that you might choose to call it "equipment" (and thus, for example, claim that 61010 applies) rather than "building wiring" (so not NFPA 70).

You can also earth things in some really weird ways. My favorite was to connect the secondary to earth through a 12V bidirectional TVS diode. Apparently this stops a lot of nuisance issues while still allowing serious currents to flow. Unfortunately, you want a bigass TVS to do this, and those are rather capacitive. So you still end up with RF issues. (No, you cannot use this to make an arc fault detector. Or at least, I couldn't do it.)

Electrostatically shielded transformers are not really stock items. You will usually have to get them custom-built and they will usually end up as expensive, higher-performing C-type cores. Shoutout to Triad Magnetics for being very nice to work with as a custom magnetics vendor on that horrid project even though the project was cursed and we ended up going with someone else (which we should have known a lot earlier and not strung you guys along, but engineering and management had different aims there...), right up until it got cancelled.

Line filters are everywhere. They're generally required to pass conducted emissions requirements. They aren't going away soon, and our fault protection devices need to work with them, not blindly ignore how we've been meeting EMC requirements for decades.

Something like this?

“Though you rarely will see your bathroom GFCI trip (unless you’re dropping the hair dryer into the bath water), some kinds of larger, more complicated machinery can cause nuisance trips.”

Or the outlet itself. Some outlets end up false tripping, and need to be replaced. Probably happens with GFCI breakers, if that's where the GFCI is. Of course, normal breakers sometimes false trip and need replacement, too.

We have had whole-house GFCIs (or RDCs as we call them here) in the NZ electrical standards for 20 years, they seem to be pretty reliable, I've never seen them trip for without a reason.

I have seen them trip on devices that were barely faulty. Devices which worked fine on a regular outlet, but would trip a RCD.

But I've never seen an EV charger trip an RCD!

It's actually kinda easy - the way GFCIs work is pretty neat.

You pass the live and neutral through the same magnetic field sensor. So long as none of the current is escaping to earth, you get an equal current in each direction and the total magnetic field is zero.

The problem is you can get a 5mA leak to ground because of, say, condensation inside a socket. And ripping out your house's wiring in search of that is a lot of expense to deal with a relatively minor danger.

Personally I've noticed buzzing or interference with some lighting on gfci circuits.

The way the AFCI mess played out lost them so much credibility that it is hard to take this seriously as being about "safety" any more.

The reason why is that those devices create arcs, and AFCI breakers are completely unable to handle them. Some regions require AFCI breakers, so a significant portion of household appliances will occasionally trip the breaker.

The worst part is that it isn't particularly consistent, so your fridge could last for years without tripping it, but as brushes wear the arcs they regularly create increase the chances of a trip, until one day you find that all your food is ruined, because the AFCI breaker tripped at an inopportune time.

Fortunately, my fridge trips the AFCI very reliably, so I was able to detect it before losing any food. All I had to do to fix it was make a few passes with the hot wire through a ferrite bead, right before it connects to the AFCI breaker. It completely blocks the arc-created RF that the AFCI is detecting, disabling the functionality of the AFCI, all without any code violations, because while the AFCI is required, the ferrite bead isn't prohibited.

The only two times where my AFCI tripped were 1) my blow-dryer shorted out due to a worn out cable (WAI) and 2) the PSU on my PC started tripping the AFCI (sent back to the manufacturer and got a replacement). So in both cases, at least for me, the AFCIs caught real problems.

Not a single trip of the GFCI function so far including vacuum, fride, and various power tools (and it's great peace of mind to have this with kids in the house).

That's a common occurrence with an AFCI breaker and a switched mode power supply.

In my last apartment, I had multiple AFCI breakers nuisance trip with multiple PC power supplies, usually when the GPU has heavy usage.

Eventually I "solved" it by getting a double conversion UPS.

It turns out that detecting arcs is hard. Really, really hard. The window between "normal operation of some random crap that's plugged in" and "bad stuff" is tiny, or even nonexistent. (Old tools with brushed motors arc during normal operation!) I worked on an arc fault detector once, as part of a larger project. We never got the thing working before the whole project got canned. It was consistently the one piece of the project that I was reporting to management as "We have no idea how to make this work. The rest of this thing, we have a plan for (maybe a bad plan, and maybe we won't execute well; such is life in R&D), but the arc detector doesn't work, we have no plan for it, and no idea how to make a plan." And we were doing a next-generation version of a device already shipping — we should have had a working arc detector right out of the gate! But it didn't work.

(The tests for arcs, incidentally, were insane. We used the test procedure from the previous-generation product, a special board made up with various "simulated arc strengths". Then we set up a low-kV range power supply, put on those giant rubber gloves that you see in cartoons, and moved in a pointy probe, by hand, toward the right spot on the test board until it arced over. This was less than reliable, and rather difficult to automate. (My proposal to automate testing by changing the intern's name to "Automated" was not accepted.) It turns out that the arc signature is deeply dependent on the exact test method you use. We had another fixture designed in-house involving a variable-distance spark gap made with two adjustable spheres. Its results were completely and totally different than the other board, so we just pretended it had never existed.)

So arc detection is difficult. It will not surprise you then to learn that the first generation of AFCI devices and breakers did not actually work correctly. They were notorious for tripping randomly and generally not things you wanted to have in your life. They were also expensive (probably paying more for the testing than for the materials cost). The NEC mandated their use anyway. Their reliability was so ridiculously poor that there was general agreement among everyone that that part of the NEC should just be ignored and standard or GFCI devices used instead. Did the NEC care? No, they insisted that AFCIs were important. Even though they didn't work. This made a lot of people start to distrust them.

We're on second or third generation AFCI devices now, and they seem to have improved a lot. They don't really false trigger anymore. But do they correctly trigger, or did they just desensitize them so they don't do anything at all? I haven't tested, and I don't want to!

It's also worth considering the risks mitigated by AFCIs. Arc faults at 120V are not really that common, and when serious arc faults do occur, they usually result in an electrical fire. Fire is certainly very bad, but I'd say it's a lot less dangerous than the nearly-instant death by electrocution that GFCIs prevent. (Note that at 240V arc faults are much more common, and up at 480V they are straight-up lethal in their own right. DO NOT FUCK WITH 480.)

So the NEC mandated AFCI devices that caused major hassle, mitigated minor risks, and cost a lot of money. That annoyed people. This came on the heels of them requiring GFCIs everywhere (same issue; ground faults in non-wet locations are not really a major risk with North American style TN-C-S earthing, but at least GFCIs work). That annoyed people. And then they had required TR receptacles everywhere (which, personally, I consider of very little benefit, though I won't argue with anyone who disagrees; at least it's obvious what's going on there), when that technology was also half baked (seriously, early TR receptacles were horrid to use, though they are pretty decent now). That annoyed people.

You can see the trend. A lot of crappy technologies were made mandatory at our expense for minor to modest gains in safety, high losses in reliability, and extreme costs in annoyance. Thus, the question: who are these guys really looking out for? Us? Manufacturers? Insurers?

I have all of my grandfathers old Craftsman steel-shell electric power tools with brushed motors. I put a new cord on one of the hand drills a few years ago (the old cloth covered cords are terrifying) and tried using it for a project. That thing throws sparks like a Zippo.

I think the NEC is beholden to the people who make this stuff. Right now I have a 14-50R in my garage (I don't even use it, I have it shut off at the panel; I don't have an EV, this is just new construction). The standard breaker is $18.98 right now at the big orange store. The GFCI version they're trying to make mandatory is $190.68.

I think that says all you need to know.

(And before anyone says they must cost that much more to make... they do not. I have designed GFI and AFI devices. You need to add a circuit board, yes, a pretty rugged one. The ordinary breaker is all mechanical. But that does not cost $170 more to do.)

The discussion in the article is about mandating that weirdo breakers also contain GFCI/AFCI components. Unsurprisingly, manufacturers charge a lot more for the oddball parts.

(My load center's vendor also seems to be particularly bad with the price gouging, but I didn't exactly choose it, so in that respect it's perfectly representative of what gets chosen for people.)

Notwithstanding that electricity for any use already has a per KWh tax added. Plus sales tax of course.

Indeed the VAT is a nuisance, actually the most regressive form of taxation possible: rich people with enough income who can afford to spend only a fraction of it, end up paying VAT accordingly; while low income citizens who have to spend all their salary end up with an additional, significant tax burden on their whole net income.

I don't think the breaker for the EV charger has ever tripped, but if it did, it's very easy to access it and reset it.

Similarly, inadequately waterproofed wire splices in boxes in the ground are very common. Code should, but does not, require GFCI protection on these circuits.

IMO outdoor circuits, with few exceptions, should be GFCI protected, possibly with the thresholds set based on circuit rating. So a 200A circuit could have a threshold of a few amps, and a 15 or 20A outdoor receptacle or lighting circuit should have a threshold no higher than 30mA.

And of course the wires coming out of an EVSE should be protected at 30mA or less, which they already are. And the wires coming in should be protected based on circuit rating if the EVSE itself is in a location exposed to water.

If your device is constantly tripping your GFCI, that was a decision some bean counter (or totally clueless contractor) was willing to make, not a god given inherent fact of the universe. All that you know is that the think could be saving your life as the fault current has to go somewhere that isn't back into the system. But of course now the US has an unelected car manufacturer in government, so it is important to let them reduce the quality of things so they can make more money. The actual solution is to test products before they hit the market and test/overhaul dangerously wrong wiring in houses.

If your gas safety valve keeps shutting down the gas because your gas bottle is heating up next to the flame, vuess what: the solution isn't to remove the safety valve.

Is there an EVSE that doesn't have this problem?

This discussion might interest you: https://old.reddit.com/r/evcharging/comments/15blqlj/how_som...

Or let's phrase it like that: If the proper cables are used and if the wiring isn't absolute dogshit next to other absolute dogshit the cited reason isn't the reason.

Try to induce 5mA of foreign circuit into a cable on purpose and you will see what I mean. Measuring equipment exists so we don't need to guess here..

The issue is more that manufactureres calculated with a 30mA threshold for ages and if they did a bad job, they produced equipment that just barely made that threshold. Typically such norm changes are known well ahead, I am more familar with European norms, but changes like these are known a decade ahead.

So it isn't as if manufacturers of such equipment are suddenly surprised by new regulations. And if the new rule starts to work that should only affect newly built unints (or units where the electrical installation is renewed). So if your EV charger trips the GFCI because of bad electrical wiring, thr wiring likely had to be replaced due to new norms anyways..

Why the thresholds for different areas differ is usually a mix of historical reasons, lobbying and a "we didn't get around to that yet". It is hard to answer such questions in isolation, maybe marine equipment has other maintenance cycles, crazier cabling requirements, maybe there are fire suppression measures that allow to relax that requirement more, maybe it doesn't make sense at all.

As someone who has read through nearly 100 GB of norm PDFs I can assure you that just comparing two thresholds in isolation is practically worthless if you ignore the other differences in the rules.

I'll admit I don't know what kind of currents they see, but 5mA on transients wouldn't be particularly surprising. There is also the factor of how sensitive the GFCI is.

And if it’s resistive leakage, that’s almost a watt of dissipation - also huge and probably a short in a cable and potentially a fire risk.

5mA is a massive threshold for well designed devices

I wonder if there is any telemetry that gives statistics on how often the EV chargers already trip?

Also if my charger trips it doesn’t enable automatically I need to that cycling the power on it.

Used to be the advice was to put in a hardwired charger and bypass this entirely, but now they’re ruining that. This is one of those cases where having a screwdriver and a phone with YouTube is a huge advantage.

…

“It kept flicking off every time I plugged my car in! Got a new one and it did the same thing, finally the helpful guy at the hardware store suggested using this one and now it works fine!”

I’d argue you aren’t taking on much fire risk anyway. Your medical insurance would probably be more interested than your home insurance. Also, don’t bathe with a plugged in car charger. In case that needed to be said…

Certainly don’t go screwing around with mains electricity until you can articulate all of the above, and have an electrician friend show you how to make proper connections and such. But for most of HN… it wouldn’t be hard at all. Stripping insulation off 6/3 wire would be the hardest part of the process for most people here to install a whole new outlet for their EV. Changing a breaker is nearly child’s play.

This only affects new builds after the codes come into force. EVSE manufacturers will just have to adapt.

It is like the people holding this view don't understand that Wish.com and Aliexpress exist.

Look out your window at the power pole, you'll see a transformer. That has breakers, differential relays, and other protections.

> And that protection?

Substations have RTUs and SCADA systems that are constantly monitoring everything for faults. They have cool shit like oil breakers that can kill even the large inputs to the substation.

> At some point you have to stop.

No, you don't. The protections go all the way back to the power generation site.

You don’t pay people to monitor your home electric network 24/7. You don’t risk damaging a power plant when there’s a short-circuit at home.

My charger is connected via a NEMA 14-50 outlet, that uses regular GFCI breakers in the panel. They have not ever tripped, outside of me testing the outlet.