I have a question for you as a Brit. I live in an Asian household (my wife is Asian). We have a hot water boiler, as most Asian households do. It keeps 4L of water at "tea" temperature at all times (after boiling it).
When we want tea, we just fill up the cup with the already boiled and ready water. It's super efficient because it's super insulated so it barely takes any energy to keep it hot after it's been boiled.
Why don't Brits (and other tea drinking cultures in Europe) do this?
I'm not sure how much difference this makes, but when I use the hot water boiler at work, the tea definitely tastes slightly off compared to using a kettle at home. But it's also possible the hot water boiler at work is not producing hot enough water.
Ahmad and Impra are both several cuts above Twinings, not expensive (especially as bulk loose-leaf) and can be found in standard grocery stores, or ordered online.
If you've a specialty tea shop nearby, that's all but certainly better, though it can be pricey.
You'll find there's a whole new world out there, and may regret discovering a taste for real whole-leaf teas.
Greens, whites, blacks, fermented, oolongs, darjeelings, matcha, gunpowder, pu'er, etc.
There are also herbal teas, such as rooibos, not made from sinchilla (tea plant), but also tasty.
Best is to buy a bag of loose tea from a tea shop. The leaves are whole, it's not powder. It's usually not hard to find, but they don't sell it at most supermarkets.
An Asian style water boiler maintains the temp just below boiling, so there isn’t any reboiling throughout the day. Think of it as a water boiling thermos.
You’re meant to replace the water daily. Not sure how many follow that guideline.
ETA: Only the so-called “hybrid” models have vacuum insulation. It’s worth the extra charge.
But as it cools the gasses reintegrate. So I'm not sure the science backs this up. Water at the same temp should have the same amount of dissolved gas regardless of how it got to that temp (given enough time for the gas to reintegrate).
I think you're incorrectly discounting that time aspect. If you leave a glass of tap water sitting out, eventually there will be a bunch of bubbles clinging to the sides of the glass. This doesn't happen immediately, but rather over many hours. Similarly, I would think that boiling water won't reach its gas equilibrium during the course of making tea, but hot water sitting around waiting to be used will.
I agree with this. I develop my own film and the way I manage water is to boil it, put it into sealed bottles, and store those in the fridge. This avoids bubbles more readily than just using tap water (which is over 20C in the summer anyway, which is why I do the refrigeration thing). No, I don't have an aerator on my tap either. Obviously that introduces a lot of bubbles.
Nearly all tea advice is ideology and superstition, explicitly because most people like different things about tea. There cannot be a right answer for such a personal preference.
>Nearly all tea advice is ideology and superstition, explicitly because most people like different things about tea.
That's BS. It's true: people do have different tastes and preferences, so opinions are just that. But it's not "superstition": different brands/blends of tea really do taste different, many times remarkably so. It's just like a McDonald's burger vs. a burger from a high-end restaurant. One of course isn't objectively better than the other (from a taste standpoint; I'm ignoring nutrition here), since it's a matter of opinion, but you will find that significant groups of people who like a particular food enough to have tried different varieties will usually form similar opinions, or at least sort themselves into different camps.
"Superstition" implies that the differences people taste are not real, and this is quite simply false. The differences are real; it's up to you which one you like better. More expensive doesn't always mean better-tasting.
These use a tank to keep a few cups of water hot at all times. The instant part is the delivery of it, not the heating. So this does not satisfy the Twinings comment you are replying to.
it doesn't. the faucet of these types of tanks is just a pipe opening and has laminar flow. it doesn't exit the normal sink faucet (which will have an aerator).
The hot urn cannot be more efficient than boiling the correct amount of water each time.
The limiting factor is the specific heat capacity of water. If daily consumption is 2l, you have to put in the joules to raise 2l to boiling, either way. If you have heat losses during the day, there's your inefficiency.
How many people are boiling the correct amount each time though? I fill my jug up all the way and then keep reboiling which seems less efficient as the boiled water keeps cooling down.
Some do. It's become a popular addition to a middle class kitchen. All offices have them.
As to why Asian households have it and we don't, I think it's simply that we have been boiling water in kettles since the stoves ran on coal, and the electric kettle is just an upgrade of that same old system
Not to mention the age of our housing stock. The Asian households you refer to, when were their homes built? I'm guessing much more recently, comparatively speaking.
Why is the age of the housing stock relevant here? An Japanese-style water boiler is an add-on kitchen appliance, like the Instapot or an air-fryer, so,
cultural differences aside, you'd expect similar adoption rates. Given that we haven't, there must be some cultural component as to why.
Some people have instant boiling water taps with tanks, they're not unknown but rare and becoming increasingly less so. I think this is because a) they're relatively new here and b) last time I looked they cost about £1k plus fitting.
The Japanese water boilers look like they cost £200ish (vs £15 for a kettle) and are bulkier than a kettle. They will save practically no time - kettles boil fast here and while they're boiling it gives you time to put the tea in and any other preparations.
It just occurred to me that Japan also uses 120V (actually I think they use 100V), so it may be just a matter of speed. You can boil water a lot quicker with your 240V outlets than we can with our 100-120V.
You're not taking the amps into account. Voltage without the amps on the circuit breaker is pretty useless. Quickly Googling indicates that a standard residential circuit breaker in Japan is 30A (3000 watt max), meaning you'd get more power than you would in the US with 120v / 15A (1800 watt max), and much less than where I live in Germany with 230v / 16A (3680 watt max).
>You're not taking the amps into account. Voltage without the amps on the circuit breaker is pretty useless. Quickly Googling indicates that a standard residential circuit breaker in Japan is 30A
Sorry, that's wrong. The breakers on my 100V outlets here in Tokyo are 15A IIRC (I'm not home at the moment). 30A sounds like an air conditioning circuit. 30A on a regular outlet would require huge wires; they're not going to wire a whole apartment with that stuff.
I actually have a kettle here, bought in Japan. It's rated at 900W. It's OK for boiling a single cup of water, but it's definitely not quick. Faster than the microwave though: microwaves here are 500W or 600W (frequently selectable), and the high-end ones go up to 900W. All this should tell you something about the amp capacity of the kitchen outlets here.
900W is how much my kettle is rated for, which means it actually draws 900W of power (which is about 9A at 100V).
For the microwave, 900W is the power transmitted to the food, not the power drawn from the outlet. All microwaves are rated this way. But microwaves are not particularly efficient; just guessing, I'd guess that a typical 1200W American microwave draws around 1500-1600W, and certainly no more than 1800W since that's the max the outlet can provide. So my microwave at the 900W setting probably draws a bare minimum of 1100W (11A at 100V).
And that's a fancy microwave; the typical microwaves here are all 500/600W. I think the most powerful one I've ever seen in a store was 1000W, so that's probably the highest power rating that can safely run on typical kitchen circuits here in reasonably modern buildings.
Age matters because in many cases the house was built with some expectations, and something else won't work at all. In the 1950s your house got a total of 4 circuits, which was enough for clocks and lights, one fridge, and a kitchen mixer (an electric range was an option and added circuits). Of course TVs arrived in the 1950s (they existed before then but were not common) and started blowing power budgets. As people started using more electric new houses got upgraded to handle those loads, but many older houses have not been updated as it is expensive (major remodel as you need to tear down walls).
Of course the above is standard, not everyone takes the standard. However it is unusual to take something else.
Builders (read electric codes) build for what is common uses. If everyone wants an something that uses a lot of power the wires will be made to handle that in new houses. However if you want that same thing in an older house you may discover that the rewiring needed makes it not worth it and so you look for an alternate.
I'm not sure that's exactly true in this context. At least, I've never been in the house in the UK where the electrics in the kitchen couldn't handle a kettle, and a water boiler for hot drinks isn't likely to use more.
What is tea temperature for you? As I understand it black tea which Brits drink should be made with water at close to boiling (100 C) while green tea should be made with water at 80 C.
My pet peeve in the US is ordering a cup of tea and getting a cup of cooling water and a teabag by the side. Fine for herbal or green tea but terrible for black tea.
My boiler lets me set the hold temp at 208f(97.8C), 195F(90.5C), and 175F(79.4C). So basically you can do all the different "ideal" temps depending on which tea you make the most.
We keep it at 195 since we don't make black teas, and then we can let it cool down to whichever tea we want or just mix it with some filtered cold to get it to temp.
At least in the German-speaking market there exist said solutions, but they are not very common (yet?). I believe keeping 4L at near boiling temperature is still less efficient than individually heating and it takes less than a minute with 3kW.
The water stays way above the temp for legionella. And the water is still pretty fresh, it ends up getting replaced every other day or so in winter. And in summer we just replace it once in a while anyway.
Also it will reboil after a certain amount of time.
Has anyone ever made a battery-powered kettle with significantly higher power than can be pulled from a wall outlet? Modern lithium batteries can deliver many kilowatts of power, and given that the total energy needed to boil the water is basically fixed, the battery size requirements might be pretty reasonable. I wouldn't be surprised if boiling water in 15s is possible even on a 120v American outlet.
At 3.6V and 45A, each battery should output 162 watts. Rounding to 150 watts, we'd need 20 of them to make 3 kilowatts. So $100 worth of batteries.
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Question #2: How long will they last? Long enough to boil water?
At the 45-amp discharge rate and with 4.2 amp-hour capacity, it should take 4.2/45 hours = 6 or 7 minutes to discharge them.
By my math, it takes 335 kilojoules to heat a liter of water from 20°C to 100°C. A 3 kilowatt kettle should be able to do it in 335/3 = 112 seconds.
So the batteries should be able to boil water around 3 times before discharged.
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Those calculations are for running on battery alone. Since you can get 1500W out of an American 120V outlet, you could make a kettle that draws 1500W from the wall and boosts it with 1500W of battery power. (I'd use two heating elements.) Then you only need $50 of batteries.
The kettle is going to be a bit heavy, though. The batteries are 70g each, so 20 of them is 1.4 kg. Also, I don't know much batteries heat up when cranking out 45 amps, but I bet the answer is a lot, and you may need active cooling and/or thermal shutoff.
Put the batteries and controller in the base, have the jug lift off from the electrical connectors to the heating elements, the jug is therefore light and convenient.
It would be better to have a box that converts 2 NEMA 5-15 120v plugs to one 6-15 240V plug.
I've seen such a box for sale, I think for the RV market. You plug into both phases of the 120/240V split phase and get a dryer plug at a lower amperage.
Now I realize that what I really want to build is a kettle with two 3kW heating elements. On a UK ring main, I can plug the two elements into two neighbouring sockets and still have headroom before I blow the breaker. I can cut my time-to-tea from 45 seconds to 22 seconds!
It's certainly possible; whether it makes any economic sense at all is a different matter. I can't imagine much of a market for a device like this. Basically you're proposing a relatively complicated device (compared to a simple tea kettle, though modern ones have a handy auto-shut-off feature) for the sole purpose of boiling water a little faster. Americans aren't big tea drinkers in the first place, so it's hard to imagine many would pay 5x-10x as much (guessing) for a fancy battery-boosted tea kettle just to boil water a little faster. I suppose it's possible though; Li-ion batteries are pretty commonplace these days.
I think it's certainly possible. FWIW car batteries can often support 1000A especially those for large diesel engines. They aren't meant for continuously loads or deep cycles though. Marine batteries may be able to overcome this.
It's probably the most remarkable difference. It's interesting how houses are wired for 10-20A of current everywhere, regardless of voltage. You'd assume that since European houses are mostly wired for 16A then US houses would be wired for 32A (or the other way around, if you know US houses wired for 15A, you would assume the European wires for 8A). But curiously that's not the case.
Ignoring the UK with their 13A/30A rings for a moment, since their wiring is unique.
Largely this is resolved by US houses having a lot more circuits. My bathroom has a dedicated 20 amp (2.4 kW) circuit for the outlets and a separate 15 amp (1.8 kW) circuit for the lights. Every bedroom in my house has its own 15 amp breaker. The kitchen has 3 20 amp breakers for different wall outlets, a 15 amp breaker for the lights, then a 30 amp 240v (7.2 kW) breaker for the cooktop, and a 20 amp 240v (4.8 kW) breaker for the oven.
For the a typical US house the standard feed into the house is 200 amps at 240v. So 48kW of power coming in we just segment it down a lot more.
It starts to become annoying when you have a home office for 2 people though. 2 PCs + 4 monitors and some random things in a room can start approaching the wattage limit. Especially given that I think it's not too common to have one circuit per room (anecdata: my house has one circuit for all outlets per story; not counting bathroom and kitchen which I believe are mandated by building code to be separate).
Lots of smaller (kw) circuits is safer than a few very large circuits. The NEC in the US actually stipulates that you must use different receptacle styles for higher ampacities specifically because it is less dangerous. If you run a small appliance on a 30-40amp circuit, you run the risk of that seemingly safe appliance pulling the full 40+ amps required to trip the breaker
Not sure if I understand - can you clarify? Did you mean that a normally safe 1.5kW appliance runs the risk of cooking itself if it's connected to a 40amp circuit? If yes, then sure, that makes sense.
> Lots of smaller (kw) circuits is safer than a few very large circuits.
Not fully convinced about the safety aspect but it definitely feels more convenient (can selectively turn rooms off if you need to work on something) - if I'm ever opening the walls, I'm going to switch to that approach. At the very least, I want to have a dedicated 20amp circuit in the home office...
Largely yes a 1.5 kW device (a 12.5 amp space heater for example) is less safe on a 40 amp circuit. Since if it fail pulling more load than designed but not truly shorted the breaker may not trip. But if you put that space heater on a 15 amp circuit it would most likely trip the breaker. As other commenters have said the UK addresses that risk with fuses in the plug.
Also I recently redid my kitchen and I added an additional 20 amp circuit just for the kitchen island outlets and it has been super nice.
Are safety concerns alleviated here by GFCI breakers? In what cases could this appliance pull more amps than it was designed for? I know it's not required for circuits outside kitchen and bathroom, but I was thinking about just replacing all the breakers with combined GFCI/AFCI ones (especially given that my circuits are so old that there's no ground on them, in which case code I believe mandates that the outlets are GFCI-protected and labeled as "no ground").
So the risk would be reduced. Since if the failure causes a electricity to travel anywhere other than the neutral it will cause the gfci to trip. A scenario where a device would pull more power would be a short developing in a heating element reducing its resistance. So it would just pull more power but all of the power is still going to the neutral and wouldn't trip the GFCI.
Also with replacing all your breakers it can increase safety. But first the breakers are not cheap. Second it can lead to a lot of nuisance trips, albeit that is better than it used to be with modern breakers.
Yeah your AFCI in theory is supposed to help reduce fire risk. Since failures like that cause arcing. But yeah it will be around $60-$80 per breaker, but there is definitely cheaper than ripping open walls to re-run wires.
GFCI is not a magic “make everything perfectly safe” - you could electrocute yourself to very dead without tripping a GFCI if all the power went down the main wires and none went to ground.
Britain solves this with fuses inside appliance plugs.
The continental European system doesn't really solve it, as far as I know, so you have thicker wires on low power appliances than you would in the USA.
The US also has fused plugs but their are not widely used for some reason. I see them mostly on Christmas lights, but I have also seen it on some small home electronics like a window fan and air purifier.
Yeah sadly having separate circuits for each room is not required by the NEC to the best of my knowledge (and might be overkill depending on the situation). Usually though best practice is to have a separate circuit though for each bedroom. Depending on how your outlets are wired it might be possible to split them off onto separate breakers relatively easily though.
32A capable wiring is much more expensive. And if we are being honest, the number of modern appliances that need more than 1800W is very small outside of the kitchen. If it were a common problem people would be installing 6-20 receptacles, but that's pretty rare. I have exactly one, and it's in the garage.
Resistive losses are related to current (I^2 R), so you need thicker wires to deliver the same power at a lower voltage. I guess it was decided that it wasn't worth the expense.
Sure, obviously. But you'd expect power requirements to be more or less the same, and the ideal wire diameter to be dependent on voltage. But instead what happened is that the wire diameter is more or less constant, and Europe just uses more powerful electrical devices.
> Europe just uses more powerful electrical devices
Aside from kettles? I guess maybe some people have electric heaters? What else pulls enough power that the extra voltage will matter? Vacuums maybe, but no, those are limited to 1600W.
- Irons are commonly 2000-3200W (3200W is 14.5A at 220V)
- Portable Induction Stovetops are 3000W
- Deep Fryers are 2000-3000W
- Hair Dryers are 2000-2500W
And of course some things are connected via 3-phase 400V (3 220V phases, because of the 120° phase offset that's 400V between any two phases)
- actual oven + stovetop combinations, about 7000W for the stovetop, plus 1000W for the oven
- many tankless water heaters, 5000W-24000W seems common
The most impactful in day-to-day use are probably kettles and hair dryers, but with stovetops and water heaters there's probably a big difference in the prevalence in gas vs electrical, and tankless vs boiler simply due to wiring.
That's a good list, thanks. I'd be interested to know what the experience is like between a 120V hair dryer and a 240V model. I don't have enough hair to worry about such things, but my wife does, and it seems like her hair dryer gets hot enough that she usually turns it down a bit anyway.
The 'industrial' level appliances are probably less of an issue, because the wiring run is limited and you can customize it however you need to. I could go down and buy a 36kW electric tankless water heater today and wire it up without any difficulty. Though it would probably be worth upgrading my 200A panel in that case.
Ranges sound like they're probably pretty similar. Typical modern electric ranges in the US are about 10kW.
Three phases would be handy for reducing the cost of wiring, though. Cost me $1500 USD just for the wire when I ran four new circuits last year. Couple of them were 50A, which is partly why it was so expensive, but mostly it's just that copper is $$$. Any bigger than 60A and I'd switch to aluminum.
I don't have first-hand experience with the difference in hair dryers either, but I imagine it's mostly air velocity? With more power you can turn more air scalding hot, meaning you can offer higher fan speeds without compromising temperature.
If you increase Ampere you must increase the width of the cable, or it will overheat. If you increase Voltage you must increase the insulation around the cable.
As an American, I have a faucet at my kitchen sink that will give me water at 195F. That takes care of nearly all my needs for truly hot water. When I do need the last few degrees to get a roiling boil, my induction cooktop has a 3700W burner that will do it in a hurry.
> As an American, I have a faucet at my kitchen sink that will give me water at 195F.
The building code for the province of Ontario (Canada) states that delivered water cannot be higher than 49C (120F); §7.6.5.1. Maximum Temperature of Hot Water:
No. The law you quoted limits the maximum temperature of hot water supplied by fittings to fixtures.
It says nothing about fixtures that increase the temperature of water and dispense it, and does not limit the temperature of dispensed water. Instant hot taps are both legal and commonplace in Canada.
We have the same. The system has a high-end water filter which then exits into a split, one outlet of which goes to a room-temp tap and the other into the heater, so we have both filtered "cold" and hot water.
It's just one tap at that sink, clearly identified, in addition to the regular hot & cold water taps. I don't run my main hot water tank at 195F, that would be dumb.
Yep, I have a separate tap at the kitchen sink which is connected to a small (about 3 liters IIRC) tank underneath. I have it set to 195F, though it can be set as high as 210F. There is a receptacle in the cupboard under the sink where it plugs in.
To be clear, in the US the "instant hot" tap (when present) is separate from the main adjustable-temperature faucet. It's normally off to the side and visually distinct. It's usually much smaller and provides a limited amount of water from a pre-heated tank under the sink.
Zero. The 195F tap is not the same one you use for normal hot & cold water. The normal hot water in our house is set to 140F (we do not have any small children or elderly, if we did I might dial it down to 120F).
Now that I have a 5kw induction cooktop I can boil water incredibly fast. However I’m not sure it’s that useful since it’s not like I’m standing there watching it, so whether it’s 1 min or 5 min doesn’t matter.
I have a really old infrared range that takes 20+ minutes to boil a pot of water. Believe me when it takes that long it does matter. (it is on the list to replace, but there are higher priorities in this house to fix first, and only limited budget)
If you use an induction hob, a classic stovetop kettle (the kind that whistles!) will allow you to boil water quickly. The large ring on my last hob was 3kw.
I have a temperature controllable "kettle" (tank) under my sink connected to a tap and I get water at 195F. I agree on the convenience. They are pretty common.
Nitpick: a cooktop is just the burners, a range is an appliance with burners and an oven. It's relatively common on newer houses to separate them. E.g. I have a 36 inch induction cooktop and a completely separate double wall oven in another area of the kitchen.
AFAIK stovetop is also sometimes used when people mean cooktop, though in my area it's more often a casual reference to the burners of a range. I'm sure that convention varies wildly across the country.
The power companies know this, and time their cutovers from Europe with the end of Eastendets, which is when people turn on their kettle for a cup of tea before making dinner.
(I’m not sure if that’s still a good hint, but it certainly was ten or so years ago.)
Less important now. Back when 17 million would tune in to watch Coronation Street 3 times a week it was a much bigger thing. It's rare to get half that for legacy live TV outside of specific major broadcasts (The Euro 2020 final pulled in 30 million) -- the 10th most watched show of 2022 only got 8 million and the soaps are lucky to get 6 - inlcuding those watching time-shifted.
I would like to see a US electric range with Schuko outlets and 16A GFCI breakers on the side, but that probably violates too many electrical codes.
Schuko makes the most sense because it's unpolarized, so appliances don't expect a neutral leg. You still have the 50/60 Hz problem, but something like a kettle probably won't care.
Or there could be a countertop "Schuko dongle" that attaches to the screw terminals on the back of an existing range, if it weren't for those meddling codes...
Though in practice, the key to boiling fast is to use less water. A 1500W kettle with 500 mL minimum fill is totally reasonable for cup of coffee/tea.
I have 20 amp sockets in my kitchen (as all newly built housing has, really) but there are no 20 amp kettles on the market. I wish I could get that extra 600 watts or power :(
No it's not. It's just against code if they use a NEMA 5-15 outlet. If GP used NEMA 5-20 outlets and the appliance used a 5-20 plug, then there's no issue.
Many commercial appliances use 5-20 plugs. Also, lots of commercial cleaning equipment seems to use 5-20, which is why you see businesses tend to only use 5-20 outlets.
I'm not aware of any kettles that use 5-20 plugs but I bet they exist somewhere.
IIRC NEC requires 20 amp circuits for the kitchen. However the only time I've seen a 5-20R in a residential kitchen is after the electrician got done with mine (he insisted code required the 20 amp receptacles).
It's not required, but it is allowed. And, the only thing you need to do is swap a 5-15 for a 5-20. No other work needs to be done and it's all compliant.
The circuit rating is 80% of nominal for continuous loads - runtimes of 3 hours or more - according to NEC in the US. Not sure what you mean by “regular appliance”; there is no such definition by code.
A kettle is fine at a full circuit load for under 3 hours.
It's not, and for laymen "continuous load" has a specific meaning in this context. It means something that runs for 3+ hours continuously, without a break.
Well they can be, until they boil dry, and the thermal cut out kicks in.
Prior to the late 70s / early 80s so called "automatic kettles" were not necessarily all that common in the UK, and one had to manually switch them off.
I certainly recall a time or two with a kitchen full of steam due to forgetting about putting the kettle on.
There are regional differences that are probably causing some confusion. In the US, breakers have a nameplate rating 25% higher than their continuous load capacity. Go to Australia, for example, and the identical breaker will have a nameplate rating 80% of what it would in the US.
So you can run indefinitely at the nameplate rating in Australia, but only 3 hours in the US. And the startup current (inrush) can be much higher than the rating. Most breakers are thermo-magnetic. The magnetic part has a much higher tripping point and allows for inrush current. The thermo part trips when it gets too hot, and that'll be the current printed on the breaker.
Practically speaking, any intermittent device that _can_ run continuously or can fail to a continuous needs to be considered as such for safety purposes.
For example, a fridge should only run the compressor intermittently, but it has two obvious cases where the compressor could run indefinitely:
* An influx of heat, like filling an empty fridge with room temperature cans.
* A door being left open.
In the case of the kettle, it will likely be evaluated against it's "nominal" draw after the initial startup. If the auto-off sensor were to fail, it could run continuously at the tempurature.
I probably can’t speak to your jurisdiction, but no electrical inspector I’ve ever met would consider those loads continuous - in its precise, non-colloquial meaning - for the purpose of rating the circuit.
An appliance manufacturer may be under different UL regulations for failure modes of a device on a specific rated circuit. I don’t know anything about that.
Even in the context of your refrigerator example (which I don't necessarily agree with), a kettle should have two thermostats - a primary one that keeps the temperature setpoint, and a safety cutoff in case the primary stops working. In both fail and the kettle is somehow drawing its nominal power for hours at a time, the main safety hazard is going to be the kettle itself trying to dissipate >1Kw.
Yes, laymen and non-experts are going to use words to mean the wrong thing. NEC defines continuous load as 3 or more hours of uninterrupted demand. If you want to use the amateur definition, go right ahead, but understand there's an accepted industry definition of that term, even though it looks just like normal words. :)
If this is the standard then everything is a continuous load. A soldering iron or a hair dryer or a blender might get left on forever, who knows. Maybe I want the microwave to run 24 hours a day. If everything is a continuous load, why would the NEC make a difference at all?
I would install an US 240V@20A receptacle and replace the plug on the kettle.
You can also wire a duplex 120V with the two phases (you might find this in some kitchens, and in my workshop). Then you can make a dangerous extension cord adapter combining the split phase 120V into one 240V female plug.
I'm struggling to understand how the British grid works, as an Italian transplated to UK. IIRC in Italy most residential circuit breakers have a limit of 3.3 kW, so it's pretty easy to trip it with a few appliances running, and we don't even use electric kettles that much.
Yet in Britain, with a 3 kW kettle, I've never managed to trip it, with a combination of laundry machine, electric oven, microwave, dishwasher. Is there no circuit breaker limit?
When when the UK was rebuilding the housing stock post WW2, ring mains (or circuits) were designed to both increase consumer safety and to combat the anticipated post-war copper shortage. This design allows for high integrity earthing and greater power per unit of floor area for a given cable size than a radial circuit. Most white goods (Dishwashers, washing machines, etc.) are locally fused and often ovens are on a separate ring with their own fuses in the distribution board. This is why you rarely trip the circuit. It can be done though.
Post WW2 for newly built small flats, ring mains were designed to save on copper (as it was in shortage). The intention was to allow for 3-bar electric fires to be operated as 13A loads, and be moveable between rooms.
Rings are more complex to test, and have nasty failure modes. I'd argue that they should only be used in said small flats, and that 20A bus/radial runs should be used in larger builds. i.e. any modern house, rather than a flat. Said run the supplying all of the sockets in any given room, it does though require a larger "consumer unit".
The rings have a 30A (or now 32A) at the "consumer unit" (distribution fuse box) with two cables running in a loop around all sockets in the circuit. The cables have traditionally been 2.5mm, and open clipped, so rated at around 27A (based upon preventing overheating).
Hence when operating properly, the wiring in the circuit can carry 54A, the circuit is fused at 30A (or 32A) to protect the cable, and an individual load is limited to 13A (being the highest cartridge fuse commonly available).
There may be several circuits, and they all have independent breakers. Certainly, an electric cooker/oven will be on its own circuit as it has higher requirements.
Then, standard ring circuit is 32A, and individual sockets are limited to 13A (via fuse in plug). So you will need to have 2 kettles on on the same circuit and then add a third device pulling not an insignificant amount of power (32 - 2x13 = 6A) before the breaker trips. This will be safe if the ring circuit is not faulty as they are usually wired with two 2.5mm2 cables (two because it's a ring) that have a standard rating of 24A each...
UK electrics are mad - with the ring main and what not requiring fuses in the enormous plugs. All vestiges of post-WWII design. By code a modern American kitchen must have:
- dedicated 50A 240V for an electric stove or oven (unless gas service is present)
- dedicated 20A 120V each for the fridge, microwave, dishwasher, disposal (the latter being uncommon outside the US and Canada). The last two often share a circuit.
- two 20A countertop circuits with GFCI protection (what the Brits call 'RCD' - the difference being ours trip at 5mA vs 30mA and won't knock out half the house.)
You assert that it's mad but then describe a mad situation in the US.
A typical British kitchen will have a ton of sockets (although never enough), to plug in a fridge (or two, or three), a microwave (or several - they rarely goes about 1kW anyway), a dishwasher, a washing machine, a tumble dryer (UK kitchens tend to have washers and dryers, rather than bathrooms. Larger houses have separate utility rooms)
The only thing on a dedicated circuit would be a hard-wired oven.
Thinking that having dedicated independent circuits is madness sounds like Stockholm syndrome. The point being a single faulty appliance won't knock out the lights and sockets to half the house simultaneously (a common occurrence during a fault in the UK, especially the RCD). It's also quite convenient to switch off a single appliance for service. Yes British sockets are all switched but not necessarily in a convenient location.
A software analogy would be running all your services on separate VMs, as opposed to running them all on a single server which could go down at once.
Brits don't even put outlets in the bathroom, minus a current-limited transformer-isolated one for an electric razor.
Ah, the regs have changed and we can now have a full socket in the bathroom as long as it's far enough from the bath (.6 + 2.5 = 3.1m from edge of bath), which rules out most bathrooms...
My apartment in San Francisco which I pay an absurd amount of money for has just two or three 20A circuits in total going by the breaker. I regularly trip the power.
How old. What you describe sounds like it was built before 1970 and never updated to modern standards. Since the wire is often in okay shape few consider it worth the cost to replace it even though it really can't supply enough power for modern uses. (often you have to replace it all as if you touch it the insulation will break and then it isn't okay)
> in Italy most residential circuit breakers have a limit of 3.3 kW
Wait, really? That’s seriously underpowered, though I guess if you never need electric stoves or heating it could be somewhat usable. An ex-Soviet big-city apartment building will usually support 40A (~9kW) per apartment, and in France I had the impression that the values were similar—except for student dorms, which are supplied and wired like apartment buildings despite the density of occupants being 3x that or more, because apparently the builders could not into engineering and the uni authorities find it easier to blame the occupants (yes, I’m still a bit salty about that).
I haven't lived in Italy for 10+ years, so I don't know if anything has changed since, but that was the limit for all houses I've lived in, and from a quick Google search, it depends on your contract — the lowest is a 2 kW limit, 3.3 kW is the most common, and you can ask for an increase for an additional monthly fee. Heating and stoves are usually gas-powered, we don't do electric except for water boilers.
I have always wondered if those limits and the high electricity costs are because Italy abolished nuclear energy post-Chernobyl, doesn't have a massive oil and gas operation, so most of it is imported at a premium.
We should thank whoever came up with the idea of abolishing nuclear power in Italy. What a big mistake!
> if you never need electric stoves or heating it could be somewhat usable
Heating and stoves in Italy are usually gas-powered. Ovens and kettles are electric but normally do not exceed 3.3 kW, however, we need to be careful not to use too many high-consumption appliances together (e.g., oven and washing machine).
The introduction of increasingly restrictive energy classes for electric appliances in recent years has mitigated the problem to some extent anyway.
Italy has almost the same per-capita electricity consumption as the UK. I suspect any residential limitations are made up by industrial and transport usages.
You guys really need to get on the solar panels, though.
That ~9kW is probably split over 3 phases. Here you have 3x20A main breakers and then each circuit has a 10A or 16A breaker. So about 3.7kW limit for larger appliances (16A * 230V) on a single circuit, but should not exceed 20A on one phase. Stoves can be connected to 2 phases, 400V and get 7.2kW.
In the Soviet system, usually not. There are often several downstream circuits with their own 20A or so breakers and wiring (e.g.: kitchen stove, normal kitchen sockets, bathroom sockets and lighting, other rooms’ sockets, everything non-wet lighting), but each apartment is normally supplied from a single phase. On the other hand, different apartments on the same floor (or different single-family homes on the same street, etc.) might indeed be supplied from different phases. Normal (Schuko) wall sockets are most frequently 16A (so yes, 3kW kettles max), stove sockets (and circuits) might be up to 32A, still single-phase.
(That’s not to say the system is ideal, of course. E.g. GFCIs have become common only in the past fifteen years or so, and in a country-home setting I’ve actually encountered disposable screw-socket [IEC 60269] fuses.)
In a perfect world a ring circuit is a clever invention - it offers a circuit that can safely deliver about 7.3kW with hardly any more copper than normally could deliver about 4.6kW.
However in practice they have a hidden failure mode - if you break the ring they will carry on working apparently without problem except it’s quite possible that you now have overheating cables in a wall somewhere. In the real world houses are full of changes (both DIY and professional) that inadvertently break the ring and it’s not at all uncommon to see in a house with even modest refurb works having been done.
Going from memory but this is an artifact of WW2. There was a copper shortage so they decided to save on wiring costs by running only a few high current circuits through the whole house. The appliance plugs are instead fused as any fault in the appliance would happen after the plug. This is why UK plugs are all fused - they are the final branch circuit over current protection device. I actually like the idea.
> I'm struggling to understand how the British grid works
Like most things, understanding the history helps. The ring circuit was designed because it uses less copper than other methods - and copper was scarce after WWII. Almost all other design decisions either come directly from the idea of saving copper, or the idea that there are not enough Legos to step on so the electric plug must substitute.
That sounds almost as bad as what we have to deal with in the US!
I live in an early 20th century apartment in San Francisco and I quickly learned not to run my 1.8kW kettle at the same time as my 1.2kW microwave as it would consistently trip the power.
More annoying is when the fridge compressor motor starts up while running either as that also trips the power.
The difference really is night and day between a US and UK kettle.
The worst part of the British system though (although I don’t think this has anything to do with voltage, IDK) is there is nowhere to plug-in your razor, hair clippers, hair dryer, toothbrush, curling iron, etc. etc.
That's building regulations, sadly. Sockets need to be multiple meters from splash zones, but there's an exception for shaver sockets, which have their own transformer, limited amps, and have a plug that looks very similar to the non-grounded EU plugs.
Yeah, both bathrooms in my (UK) home have such sockets, I don't actually use them, the electric toothbrush gets charged by this desk instead, but they exist.
Regulations change over time, this home's bathrooms are all interior, with fans to evacuate moisture, and the toilets accordingly have internal overflow†, both these features were not legal when my parents home was built.
† Historically for a residential toilet in the UK if the water rises above the intended maximum level in the tank, it just runs into a pipe to the outside of the building, in principle you can now see what's wrong and it's not dangerous... but, if you don't fix it promptly this results in a stain on the building exterior, as well as potentially wider water damage, plus it can freeze in mid-winter which isn't good. But wait, a toilet has a very obvious place to dump unwanted water, it's connected to the sewer and if that is broken you've got much more serious problems. So a modern toilet tank just re-uses the flush mechanism to dump excess water the same place as everything else. This elegant solution, already needed in some commercial applications, was I believe made legal in newer residential building regulations maybe in the 1980s.
Thank you, now I have even more highly specific but useless information about British homes. It will sit next to my knowledge about why you guys (used to) have two faucets.
Yes - though we call them RCDs and they're typically located in the consumer unit. Up until recently they'd be shared across several circuits (a "split" or "dual" RCD consumer unit). Nowadays regs are pushing for each cicruit in the consumer unit to be protected individually by their own RCBO (almost the same thing as an RCD/GFCI)
No, we can still do that -- I have a dual-voltage shaver point next to my bathroom sink with my electric toothbrush plugged in.
There's a famous, common 20VA fixture by Legrand with a distinctive symbol. I asked an electrician about this last year. Most electricians will still fit them.
It won't supply a hairdryer or a pair of curling tongs, probably. Not that you really want such things in a bathroom or without an earth pin.
Yeah, it's fine for me as all my stuff is rechargeable and cordless anyway. But my wife needs her hairdryer. In the US any plugs that could get wet are GFCI [1] so you just wait for it to dry out and then push the reset button.
I've rarely had it happen in the bathroom, even with outlets right next to a sink. But I had an outlet at ground level outdoors that would trip during heavy storms sometimes. We fixed it by putting a physical cover over it.
As an American, I find the boiling speed of 1L in an electric kettle to be remarkably fast compared to drip coffee or boiling on the stove. Granted, that says more about my expectations than the actual speed.
Generally I use an insulated 4L kettle that stays warm all day, so it heats up very quickly when needed and somewhat negates the issue.
I find with electric kettle that I use the right amount of water since there are markings for volume. It also heats up to the right temp for coffee instead of to boiling. Both mean that electric kettle is faster than on stove. I like that it will maintain right temp for the second pour for coffee.
An induction stove is still really inefficient at heating water, compared to an electric kettle with the resistive element in the water and 3kW of power.
There is a small difference but not much. I compared my 230V Kettle with my 400V induction stove and it’s within 5% or so. Obviously it depends a bit on what pot you use. I’m guessing most losses come from the lack of insulation on the metal pot.
For the induction cooktop, there's circuitry to drive the induction system, which then creates magnetic fields, which then interacts with the metal pot, which gets hot and heats the water on one side while radiating heat into the air on the other. There's a lot of stages for losses here.
On an electric kettle, there's just a heating element, often directly bathed in the hot water.
There's absolutely less losses with the electric kettle, so for a 3kW kettle and a 3kW induction cooktop the kettle is slightly more efficient. Slightly.
Hmm, I measured it once (temp increase over time, computed back into watts, compared to a watt meter on the induction cooker), and I found that of the 3,5kW I put in, 80% actually convert to temperature increase in the water. That is not too bad, is it? Are electric kettles more efficient?
Are people actually using induction stoves for tea, though?
For me, a big selling point of the kettle is that you don't have to clean it and stow it after every use, so I would still use the kettle even if it was slower (maybe no longer for pasta or when cooking in general though)...
edit: I guess you could just get a teapot that is induction-compatible, didn't think of that.
Ours is a Smeg model. The two large rings are 2.3kW, with a outer booster ring to 3kW. The problem is if I'm just boiling water for my tea with a saucepan, only the inner ring is triggered. I can put a large pan on there and get 3kW to match the 3kW kettle, but then I've got to warm a large metal pan too, whereas the kettle has very little thermal mass and is lightweight and easy to fill too.
A properly sized tea kettle would solve that but since you already have the electric kettle there’s no sense in buying a new stovetop vessel until the electric kettle burns itself up.
US induction cooktops/stoves are almost always 240V, unless you get a little countertop burner.
> I'm kind of surprised by this.
As am I. The first time I put a small pot of water on my induction cooktop and turned it on maximum power, I laughed out loud. If I'm only doing enough for a cup of coffee or tea, it starts boiling so fast you don't want to step away.
My in-laws have fried three different induction hobs boiling a kettle on them. Good quality brands too, they just can't seem to cope with frequently being set to max.
No, it really does not. A typical induction stove has ~2kW of power on each element, and is ~20% less efficient at heating water than the resistive kettle.
This makes it about half as fast at boiling water.
Note that the 3.7kW element can only provide all that to a single vessel if it covers the entire area of the element.
The resistive element submerged in the water dumps very nearly 100% of energy into the water. The stove heating the kettle has many more sources of loss, but mostly that it first heats a piece of metal, which is not fully submerged in water.
In theory, in practice the induction heating on a regular pan is faster than my kettle by almost three times. YMMV on type of kettle and induction hob used. But it generally means that if you live in the US and you have an induction hob, there is absolutely no reason to buy a kettle.
My experience with US induction stoves is limited but I believe it can also deliver 3.5kW on boost. My induction stove boosts to 3.8kW for heating which beats my kettle significantly. I also measures the efficiency and it’s quite comparable.
A British kettle on 230 volts boils enough water for a cup of tea in about 45 seconds. (3 kilowatt heater, 300 ml of water, theoretically takes 33 seconds, but slightly longer because it has to heat the body of the kettle too)
Install an A/C socket in your kitchen. Then buy a British 240 volt 3 kilowatt kettle from eBay and wire on a US A/C plug (NEMA 6-15) - hooking the brown and blue wires from the kettle to the two line pins, and the green/yellow wire to ground.
This would be both code legal, safe and functional.
It would also be possible to use a clothes dryer socket (NEMA 14-30), but you should install a smaller than usual breaker for the circuit (15 amps), since the british kettle normally has a 13 amp fuse in it's plug, but a NEMA plug does not contain that.
Pretty much. My office building was formerly a woodworking shop and has wiring for 220V. Long ago I bought a laser printer on eBay. The seller omitted to mention it was a 220/240V model (probably why it was cheap). Laser printers unlike most appliances are not dual voltage because the fuser is run directly off the ac supply line. So I wired in a 6-20 outlet and changed the plug. Worked fine for many years. I also have a table saw running from a 6-20 outlet. There is a 6-15 NEMA type that presumably would provide a UK compatible supply. I think the problem might be how to provide in-wall cabling that's to code for 220V. In my case I already had conduit with THHN wire.
Not necessarily to code, consult your electrical engineer and lawyer before doing your own wiring, etc.
> I think the problem might be how to provide in-wall cabling that's to code for 220V
That's no problem, standard romex nm-b is rated up to 600V. The only real difficulty in doing that in most US homes is that it's all or nothing. You'd have to upgrade all receptacles on the circuit to 240V. Depending on when your home was built, the kitchen might well have several circuits for the wall receptacles (even just one circuit per receptacle, not terribly uncommon in my area), which makes converting one of the circuits to 240V pretty trivial.
Given how many appliances these days use switching power supplies capable of a wide range of voltage, I wouldn't be totally surprised if it was possible to wire an entire house with nothing but 6-15 or 6-20 receptacles and not have too much difficulty sourcing compatible appliances.
I believe that US code requires a dedicated circuit for all 240v outlets. Only 120V outlets can be chained. The only people who use 240v outlets are planing on using all the power it can provide, if they want a second outlet they want a second circuit as well.
Check with your local codes of course. Even if the local codes allow it, your building inspector may not.
Most kitchen appliances require the right voltage. They normally have a heater or motor driven direct from the AC voltage.
Most devices you'd use outside the kitchen usually will work on any voltage - with notable exceptions being vacuum cleaners, washing machines and fan heaters.
For sure you'd want to be careful. My Kitchenaid stand mixer would certainly be unhappy if it were plugged into a 240V outlet, but Kitchenaid makes a 240V version that I could replace it with. A lot of work, but technically doable.
Probably about as likely as wiring up DC receptacles throughout the house. Zero.
12-2 NM/Romex is fine for 240V (120V+120V), and is commonly used for things like large ACs, heaters, etc. Mark the white wire with red electrical tape at both ends (or really any color besides white/grey/green, but avoid black because while technically correct it just blends in as regular electrical tape).
Any kettle with a flat bottom (no exposed heating element) can be used with far less water than the 'min' line - and some models don't have a min line at all.
All new kettles have boil-dry protection as well, so they won't be damaged with no water at all.
We drink an unbelievable amount of tea. Firing up the hob each time would be silly, when you can fill a kettle to the minimum and have boiling water in an incredibly short time. Not much more than half a minute with a good modern kettle.
It does in theory. There are a few taps in the UK that are marketed as being able to produce essentially boiling water (which is what our typical tea bags require). Though we tend not to put quite so much money into our kitchens.
And we would wear those things out, I swear! :-)
I think Americans think British people drink tea out of poshness, when it is the opposite. Most of us also like a posh tea now and then, some of us drink expensive leaf teas... but the majority of what we drink is optimised for fast brewing off boiling water: tea that goes black in the mug in thirty seconds in boiling water.
There is a concept here of "builders tea" -- the kind of thing a builder drinks -- which is sort of the functional equivalent of cheap electric coffee-pot coffee. That is, it's the kind you know isn't the best, but you will still drink it, and that cuts across all class lines. [0]
There is a parallel thing: the "tea urn", which is like an enormous samovar with a lever -- that you still will see in industrial canteens and at church coffee mornings and at gatherings that aren't at cafés or restaurants. Those things actually need a different kind of tea, which brews more slowly and at slightly lower temperatures. The end result is a bit like builders tea. But we wouldn't bother with them at home.
[0] We do absolutely drink coffee at home, but aside from appalling instant coffee we tend to skip over the coffee-pot coffee in the UK, to slightly more expensive ways of making coffee or to dreadful Nespresso machines. You'll see more of those or Bialetti mokas here; old style electric coffee pot percolators are now rather unusual. But Alan Adler's Aeropress particularly caught on here among coffee nerds, because that is really compatible with electric kettle life.
> USA uses 230-240 VAC, too. The only difference is that we ground it in the center, creating "split" phases, reducing the peak voltage relative to ground and making it easier to interface low-power loads. But high-power loads (stoves, water heaters, clothes dryers, etc.) operate across the full voltage, reducing the current required.
They generally don't blow at the rated current. I've reliably used a 13A fuse on something that draws 16A for a while when starting up and never had a problem. Obviously RCDs etc are more accurate, but wired / cartridge fuses are always under-rated, in my experience.
Most fuses are slow blow - they will allow somewhat over the rates power draw for a while before blowing. Many things (motors) take a lot more than rated current for a few seconds and this is perfectly safe so the fuse shouldn't blow. The purpose of the fuse is to prevent a house fire, if your wires are good for 13 amps that means at 100% duty cycle, you can draw 16 amps for "a while" before the wires get hot enough to burn the house down, so long as you drop under 13 amps for "a while" so the wires cool down and never get hot enough to start a fire the fuse is working.
Note that the above is about safety. If you are going to draw 16 amps you should stick to a circuit rates for that, as it will have less resistance and thus waste less energy.
It's possible to ask an electrician to install a 240V outlet in the US and then get a UK-spec kettle. You just need to make sure the kettle doesn't care about the frequency difference (probably not), and the hot-hot vs hot-neutral difference (also probably not).
Possible, but the outlet will have a different plug. Most window air conditioners use that type of outlet, and some garages will have it for hobby equipment. I don't think you can legally install a UK (or EU) outlet in the US even though everything that plugs into it would be just fine on our 240V power (a few clocks won't work right, but they won't be harmed or harm anything)
Presumably, you would chop off the plug on the UK/EU kettle, and replace it with your own NEMA 6-20 plug. No need to install a UK/EU plug in your house. Also works good in case you need to use some sort of weird industrial equipment that needs 240V.
Does anyone make a.travel adapter that plugs into a us 240volt socket? Such a thing is easy to imagine, but most houses don't even have an outlet you could plug it into, so the demand would be small.
I would not use a travel adapter for a kettle. They pull major current, and the quality of the travel adapters is generally not intended for that much current draw...
Somehow I've never considered my home kettle too slow in the US, even though I have tea probably 2-3 times a day. And there's an instant hot water machine at our office, so it's not like I've gotten used to slowness.
On the hot beverage topic, I'm jealous that the espresso gear in Europe is a little cheaper/faster. The motors that drive coffee grinders and the heaters that heat up water in the boilers work a lot easier/faster.
I used to sympathize with this take until I bought a Zojirushi water boiler, which provides instantaneous hot water. Now even a faster kettle is a downgrade in experience.
Most Americans drink substantially more coffee than tea, which is why we have a purpose built appliances for making coffee, and have had those for decades.
The reason Americans don't have a super fast boiling kettle is that very few Americans WANT a very fast boiling kettle for large portions of water. If an American wants a cup of tea, two minutes or less in the microwave is sufficient. I don't care if you think that's bad, because I want a cup of tea, not some elitist purity contest.
Errr... we have those too. Though we get our coffee trends from Australia and New Zealand.
And tea in the UK has absolutely nothing whatsoever to do with "elitism", which is something you projected onto what I said for your own reasons, I guess. The very opposite: tea serves the same function as coffee does in the USA, cutting across all class and status.
In fact the kind of tea you drink in the USA tends towards being what people here would call "posh" tea, because you drink the more unusual, expensive stuff as infrequent drinkers. Most of what we drink is robust and cheap.
Americans find our tea to be the same way we find your coffee: a distinct culture and taste that is acquired, not instantly loved.
(We'll leave it to the Aussies and New Zealanders to talk to you about your coffee; they came over and fixed ours.)
But I am reminded that it is foolish to try to convey a point in a humorous way on Hacker News.
And to follow up on this thread because a similarity occurred to me in another reply, we do use samovar-type things (electric tea urns) in other contexts (ad hoc and mobile catering), but that is about brewing the tea itself within the vessel and it requires both a different kind of tea and a noticeably different kind of scale (simultaneous volume). You do sometimes see those in company canteens though.
Typical British teabag tea -- the stuff we consume in quantity -- is brewed with water just off the boil, and consumed often pretty quickly afterwards because cold milk gets added.
(Or it goes into a teapot for brewing, and again needs to be just off the boil for that)
Given that we can boil a kettle for a mug's worth of tea in not much more than half a minute, there's no reason to use them, I think.
People like to joke about this but the reason it's called a "boiling vessel" and not a "Tea maker" is because it's incredibly useful other than just making tea, to the point that the US has also added them to many modern vehicles.
On demand hot water, from the safety of your combat vehicle, is a genuine war innovation on the same level as canned food. Especially now that combat vehicles are aiming towards having more robust electrical systems makes it trivial to implement. Hot water means hot food, means warmth on a cold day, means sterilizing sketchy water sources without chemical tablets, means you don't have to light a visible fire to make your coffee, means you keep morale way higher. Your troops are now cleaner, better fed, happier, more motivated.
