> All I know is that you'll need higher amperage with lower voltage, but it can compensate proportionally.
This discussion is assuming that the amperage is the same. The common "default" AC socket in the USA is AFAIK the NEMA 5-15, which is a 15A socket; the common "default" AC socket in other countries is AFAIK usually either 16A, 15A, or 10A, so at most you'd have one extra ampere.
Of course, if you're adding a dedicated socket where you'd expect to plug a car (or other high-power devices like a large air conditioner), you'd put a higher-power socket like a 20A one. But this discussion is, as far as I understand, about what you could find on a random garage; I believe it would be unexpected to not have at least one common "default" AC socket on am enclosed garage, but finding a higher-power AC socket would be less likely.
> For starters - a typical 15amp outlet is only supposed to have a 1,440W continuous load, 1,800W peak.
Luxury! Where I live the typical socket is only 10A, and the most common standard voltage is 127V (it varies by city, some places have 220V), so the maximum would be around 1,2kW.
(There's also a 20A socket, with slightly larger pins, but it's mostly found on sockets dedicated for window air conditioners.)
> Does a typical German house have higher-rated sockets in the garage?
At least where I'm from, it's not super unusual to have a 400V socket with 16A or higher in private garages (either for tools or people preparing for an EV at some point), but you can't count on it.
> power plugs with 16A [...] at 230V they can deliver 3600W/4600W
That makes me a bit sad. We used to have a mess of plugs and sockets, with older plugs being either two round non-insulated pins or two equal-sized flat pins (sockets that could fit both kinds were not uncommon, but sockets which could fit only one kind were also not uncommon), and a Y with three flat pins for air conditioners, with NEMA 5-15 also being popular for computers (and we had sockets which could fit both the NEMA 5-15 "computer plug" and the other two types). We switched the whole country to a really neat new plug type (NBR 14136, see https://en.wikipedia.org/wiki/NBR_14136 for a few pictures), but unfortunately it's only 10A (or 20A, but that's mostly for higher-power appliances like air conditioners; nearly all sockets are going to be the 10A variant, even though the 20A socket is designed to work fine with 10A plugs).
Our voltage can be either 127V or 220V depending on which city you live in (yeah, both voltages use the same plug, but that was already the case even with the older plugs), and on how your building is wired (even in places with 127V you can get 220V by wiring phase-phase instead of phase-neutral), so it's not unusual to be limited to 10A at 127V which is around 1200W only.
> Wait, in the US you use 15A at 120v? Here in Europe (Spain at least) the typical is 16A at 240v.
Yep! The typical US residential circuit is only 120v, 15A breaker (so 12A at 80% load). (And that may be only 110-120v.) 20A circuits are also fairly common, but it's not the most common; the majority of wall outlets in a US house will be 15A.
In this chart, https://en.wikipedia.org/wiki/NEMA_connector#/media/File:NEM... , the commonly used US residential sockets are NEMA 5-15 (labelled "Typical Outlet," for 15A breaker circuits), NEMA 5-20 (for, duh, 20A breaker circuits), and NEMA 1-15 ("Old Outlet," in older buildings).
> 1500W isn't that much of a problem. Oven breakers are even 20 or 32A.
We do have higher amperage circuits for appliances like ovens and clothes driers, but they're usually dedicated circuits and have different socket shapes. You can see the labels "Clothes Dryer" and "Electric Oven" in the chart linked above :-).
That sounds incredibly error prone and actually quite dangerous! At least a lot of AC to DC converters are universal voltage and frequency, but not all appliances!
In Australia we have only one voltage that will ever come out of a single phase socket, but the standards took the opposite approach with current ratings - the sockets are cleverly designed in terms of their current capacity so (assuming it’s been installed correctly) you can’t make mistakes without illegal and dangerous modifications. In the standard socket, you can have 10 amp, 15 amp or 20 amp, and they all have different sized pins. For the 15 amp plug and socket, the ground pin is larger, so a 15 amp plug cannot fit into a 10 amp socket. A 20 amp plug has all three pins larger, so it doesn’t fit in a 10 amp or 15 amp socket. But a 10 amp plug can still fit and sit snugly in a 15 or 20 amp socket, and a 15 amp can still fit into a 20 amp socket with no problems. It’s pretty clever.
For bigger stuff, or anything three-phase, you then have big industrial circular ones, which I think have a similar system to not let you plug a higher current device into a socket that can’t supply enough current. I believe there are also three phase plugs and sockets both with neutral and without neutral, and if the plug has a neutral pin it doesn’t fit into a socket that doesn’t supply neutral.
Higher voltage allows for lower amperage for given watts / more wattage at a given amper limit. The higher the amperage, the larger the wires need to be to avoid excess heat. In the US, standard household circuits are rated for 15 or 20 amps, in the EU 10 and 16 are common. So, you can expect a 3.5kW AC unit to work without problems in the EU while getting anything more than 2kW in North America is a serious headache.
He means the standard residential circuit (like you would plug a PC or TV into) is typically 15 amps. Larger appliances, like an AC, are dedicated circuits, usually at a higher amperage. It's not uncommon for AC to be on 30A or 60A
Multiple AC standards is just fine, so long as all the sockets are physically different so you can't screw up. Electricians are expected to know all the weird rules and get things right, but normal people can't make a mistake so it works.
Almost all US houses have two voltages, but since the sockets are obviously incompatible it all works. I've seen industrial buildings that have more than one grid connection (and in one case they paid extra to ensure the grid connections went to different sub stations)
Yep, high voltage can be useful heh. The US has 240V sockets for things like dryers and ovens, they're just not as abundant. Prospective EV owners here seem to fret about not having one in the garage, but it's not necessary.
I'm looking at an AC wall socket, with a 5 places multi plug with plugged in 2 phone chargers, my laptop's power brick, a fan. All of them are transforming AC into DC (well, maybe not all of the fan.) I guess that the problem here is that all those DC appliances have different voltage inputs so a hypothetical DC wall socket maybe would be 12 V or multiples of that and then we'd still need transformers to a different voltage. On the other side all my AC appliances are standardized at 230 V.
It's not clear to me from the description, I understand that in the US the wall sockets don't put out a lot of juice, (120 volts at 15 amps = 1.8kW) but is "Level 2" like my household wall sockets (240 volts at 13 amps = 3.1kW) or is it more (e.g. some of my friends installed 240 volts at 30 amps = 7.2kW to cut their charging time in half) ?
[ Also, presumably Americans do have electric ovens right? So your ovens can't be 120 volts at 15 amps, that'd be like a kid's toy, there must be beefier power inside a typical American house already, albeit maybe not near the car? ]
Ordinary sockets in a UK home supply ~240 volts at up to 13 amps = 3kW of power. In comparison a typical US outlet is ~120 volts (can be 110, can be 120, it varies) at up to 15 amps = 1.8kW.
In both countries a home will have some beefier power for special purposes. In the UK (unless it's a really big house) this would be different sockets rated for more current at 240 volts or just stuff wired permanently for the higher current. e.g. an electric oven might be 20A at 240V = 4.8kW.
In the US the weird way they get 110V means most homes (except maybe smaller dwellings in a multi-residence building) get 2x opposite 110V supplies so you can do 220V (which may be closer to 250V in some cases, again it varies) by wiring across the two sides to deliver power for an oven or central air conditioning system or other power hungry equipment. Again this is either wired in or uses less common sockets so that you don't plug the wrong stuff in.
> 6. North American outlets are rated for ~15A * 120V. So roughly 1800W. I can just use one outlet per psu whenever it's under 1800W, right? For simplicity let's also ignore whatever load is on that particular electrical circuit.
You're going to have a bad time with this assumption; typical non-kitchen household circuits in the U.S. are 15A for the circuit. Each outlet is usually limited to 15A, but the circuit breaker serving the entire circuit is almost certainly 15A as well; one outlet at maximum load will not leave capacity for another outlet on the same circuit to be simultaneously drawing maximum amperage.
Typical residential construction would have a 15A circuit for 1-2 rooms, often with a separate circuit for lighting. Some rooms, e.g. kitchens will have 20A circuits, and some houses may have been built with 20A circuits serving more outlets / rooms.
Contrast this to my house in NZ where each circuit is rated to 20 amps continuous and supplies a double socket rated to 10 amps continuous per socket at 230V (nominal). I can easily draw 2.3kW from a standard socket for 24 hours and have no issues.
This is really handy in a country that doesn’t believe in central heating…
This discussion is assuming that the amperage is the same. The common "default" AC socket in the USA is AFAIK the NEMA 5-15, which is a 15A socket; the common "default" AC socket in other countries is AFAIK usually either 16A, 15A, or 10A, so at most you'd have one extra ampere.
Of course, if you're adding a dedicated socket where you'd expect to plug a car (or other high-power devices like a large air conditioner), you'd put a higher-power socket like a 20A one. But this discussion is, as far as I understand, about what you could find on a random garage; I believe it would be unexpected to not have at least one common "default" AC socket on am enclosed garage, but finding a higher-power AC socket would be less likely.
reply