Why does the USA use 110V and UK use 230-240V? (2014)
electronics.stackexchange.com
electronics.stackexchange.com
As to why split phase.... I am not really sure. Really, I wish a three phase residential had become normal instead. All the advantages of split phase but now your motors don't have to suck. I have heard a three phase residential connection is common in some parts of Germany, lucky bastards.
One interesting side note is how the US last mile distribution layout is different than germany. The US uses a lot more smaller transformers, really one per street. while germany uses fewer larger transformers, one per neighborhood. not sure which one is better I bet the german layout is more efficient. but I will note it is a lot easier to keep spares and change out a small transformer.
Three phase for residental connection is pretty much a standard everywhere with 230/400V system. Only small flats and really small houses get single phase. This is because the 230/400V output of the larger distribution transformer is inherently threephase and this gets distributed to essentially all the points of connection and the only reason why there are single phase residental connection is that they are slightly cheaper (both in terms of fixed monthly payment for capacity and in terms of initial installation costs). While in US the input to the typical residental pole/pedestal mounted local distribution transformer is already single phase, so you cannot really get three phases without running additional wires to the substation (and probably also having you own dedicated distribution transformer) and thus in a residantal area you are simply stuck with split-phase.
Since it is possible to do for two phases, why wouldn't it also work for 3? More power!
Stove outlets can handle 12kW in the US... So there's plenty of power to go around. Built in outlets can go even higher, with 240V/60A being somewhat common for larger appliances.
> Stove outlets can handle 12kW
wasn't aware, in that case I was wrong, good for them
[0] https://www.miele.co.th/domestic/1512.htm?&&&info=200004302-...
https://www.subzero-wolf.com/assistance/answers/wolf/common/...
Sounds like an exciting day when one of your bulbs burns out!
And if all else fails you your circuit breaker should flip.
If bulbs normally failed short, then you'd have circuit breaker's flipping a lot more often.
If it failed closed then a bulb burning out would trip the circuit breaker.
In electrical circuit terminology, "open" means "not connected" while "closed" means "connected/shorted".
That's different from direct translation of Chinese (and I think several European languages) where "open the light" means to turn it on (by closing the circuit, naturally).
I think it's most common English engineering usage (by far) to say that a burned out lamp fails open [circuit].
the neutral grounds both sides of the split phase and mainly serves to carry current when the load on each phase is unbalanced. when the neutral is cut off from ground all current has to be carried by the phase. if the loads are balanced, everything appears fine. when it is not you end up with a spooky electrical system. as now you have a series connection with a built in voltage divider. on one side the voltage will be too high on the other too low.
A related tip is to build a "dim bulb tester" to help you diagnose short circuits on mains-powered equipment. I have a traditional incandescent lightbulb in a porcelain socket wired in series with an outlet (and a switch). A non-shorted load will tend to work pretty well as the cold/cool incandescent bulb is fairly low resistance in series with the load. A shorted load will light up the light bulb brightly but not trip any breakers, allowing the opportunity to do some troubleshooting on the bench.
I've also used this concept several times to find short circuits in house wiring. Put the dim bulb tester in series with the circuit that's shorted and then, using a non-contact voltage tester, find where the measurement on the NCVT changes. That's likely where your short is.
In building such a device, you're on your own liability-wise; please don't be dumb.
Really all modern residential connections in Europe are 400V three phase electric power, capable to immediately power an electric motor without the need of capacitors.
No matter how you put it, the US residential power grid is conceptionally lagging.
It is entirely possible to get three phase, high-voltage power in North America, it just isn't run to individual houses unless specifically requested.
Even apartments have that full 3-phases, but just for plugging in the oven and the sauna stove.
The US grid is basically 3-phase everywhere, but it's neither needed nor cost-effective to run it into the home.
Now, the 400V part is different. That would require less copper (but with a safety cost).
400V between phases so 230V per phase. Safety is provided by making plugs not expose contacts while half plugged. US plugs are really unsafe compared to plugs used in most of the Europe.
If you want to run a machine shop, it’s a pain but not impossible to get 440 three phase wired straight through to your business. But consumer “heavy” motors and induction stoves run on two phase 230V.
Anything high power, you go for this plug. I'd imagine car charging would also benefit from this but not personally in that market yet.
Plugs are usually Shuko for high power appliances (washing machine) and two smaller pins for low power (phone chargers.)
By the way, Italy traditionally had a three pin in a line high power plug but more and more appliances are coming with Shuko plugs so wall socket are either bi-standard or just Shuko now.
Btw, Europe standardized at 230/400V in the nineties. In Czechia we switched from 220V to 230V in 1993. Not sure when Italy did, but probably around the same time.
Is this sort of use common in Finland? It seems like kinda a waste of money and materials to install the infrastructure to allow everyone to run heavy construction equipment off their home's electrical supply.
In the US, a developer typically buys an entire neighborhood's worth of land and builds a bunch of houses there to sell to individuals.
Over here, the individuals will typically buy their own small plot of land and then have a house built there according to their specifications. You need to be able to run heavy construction equipment to do so.
This shows a 32A 400V socket costs under 10 euros: https://www.taloon.com/voimapistorasia-pinta-bals-101-3pne-3...
The split phase is two lives, neutral and ground. 3-phase is 3 lives, neutral and ground.
Pretty sure that’s standard for the UK
I reported it and it was sorted pretty quickly.
Larger users are presumably connected with three phases by default — that primary school in the middle of the housing estate, the retirement home that has several lifts, not-tiny shops, the small block of flats etc.
That said, a few cities/states don't allow 3 phase to residences in their building code. However most do allow it, and so it is just a matter of convincing the power company to run it.
It's nice because there's no motor to worry about maintaining and the machines can run at full power.
That said you just pay that once, after that you have your rate.
A lot of people have odd power requirements - but usually not residences. Farms typically get 400V for greenhouse fans, for example.
For example, a common big motor that needs a starter capacitor is a HVAC unit. Usually the copper to run those is extremely expensive, on the order of hundreds of dollars. Adding an additional wire may add an additional hundred dollars or more. By comparison, starter caps are quite cheap. $20 for a HVAC sized one. That also isn't counting any of the costs of three phase infrastructure for breakers etc.
That also isn't even counting that many appliances are moving to inverter based technologies that don't utilize induction motors at all, such as induction hobs. Or, many appliances with no benefit from extra phases (resistive heating devices such as ovens, dryers, toasters, etc).
Seems to me that the tradeoff is worth it.
However, for low capacity hops the cost of additional insulation and extra copper needed to achieve ampacity (for worst case fault currents-- the cable must have higher capacity than the breaker so the breaker trips first and with 3ph you have three over-provisioned conductors instead of two) may make it worse off.
Even if an extra conductor in the line was a few hundred dollars, I’d rather have one less common failure point. In AZ AC is effectively required in the summer. AC outages are similar to winter furnace outages in northern areas. I have extra caps ready to deploy (we lose a cap about every 3 years across multiple units) but have never needed to unexpectedly replace copper.
The fact that they might have a higher list price than a conventional single-speed outdoor unit and indoor evaporator coil is a red herring, as the conventional units can’t do anything on their own, and they need a furnace and a fan added to be useful.
I agree that less failure points is nice, however you have to consider the tradeoff. Is it worth $100? Probably. What about $1000? $2000? If it's $2000, why not just get a more efficient inverter based one, which doesn't have a starter cap in the first place?
Split-phase system and 110V are currently more expensive in term of infrastructure.
The distribution itself is done in 3-phases power, even in the US. The conversion to 110V and split phase is done in the last mile as close as possible to the termination point to limit losses. You have to have tiny power transformers everywhere and this has a significant cost.
At the opposite, end-to-end 400V three phases system requires to have only one large transformer by Area. Generally directly connected to High Voltage (20KV in Europe).
Standalone houses usually have multiple houses connected to one single transformer. How much depends on density of the houses. For apartment buildings and other dense power needs, there's high voltage directly into the complex, then it's stepped down within the complex to meet the needs.
Instead of those little pole-mounted transformers that are common in the US, we have one of these buildings with a large transformer for each neighborhood https://dms-cf-08.dimu.org/image/032ykUus1ixX?dimension=1200...
https://electrical-engineering-portal.com/north-american-ver...
They do currently.
I can at talk for the French and Swiss system.
- Entire neighbourhood are served by a single 400V 3-phase transformer.
- For critical infrastructure, you do have sometimes two transformers in redundancy on the same local loop in case of failure on one.
There is no need for the pole type of transformer everywhere in the street with double layers of cable like in Japan or in the US.
You might find that interesting:
https://data.enedis.fr/pages/cartographie-des-reseaux-conten...
This map references all transformers and distribution lines for the french network nationwide for terminal loops. These are open data: Enedis is a the public operator.
"Poste" is the French Jargon for transformer. BT is for low voltage. HT is for anything >1000V.
Like you will see yourself, the density of transformer is of the order of 10x less than in the US/Japanese model.
Example of appliances: HVAC, induction heaters, boilers, car chargers, solar panels inverters, ...
I know of at least one, but I am ignorant of many other things and this just comes from my understanding of AC motors but: Any directly connected AC fan will have enormous benefits in terms of performance and efficiency with three phase.
Controlling the motor with a VFD is how you increase the efficiency and performance of a three-phase motor, simply being a three-phase motor provides no efficiency benefit other than you can use slightly smaller conductors to power the motor.
The problem is getting the motor to start spinning. You cant start all motors on just one or two phases. And if a motor isn't spinning, it's essentially a short.
Three phase wiring is so ubiquitous here, there is nearly no additional cost.
It may be offset, as others point out, by power delivered being higher (and thus, wire gauge can go down) when running 3 phase... however that will largely depend on the load.
I have monitoring on all the phases on my house (in Sweden) and I can charge two electric cars, run the heating in winter, run the washer and drier and cook with two ovens a microwave and the induction hob at the same time and everything just works.
Things on three phase in my home: swimming pool, sauna, induction hob, electric car chargers, heating system and I have sockets to plug-in welding and other power hungry equipment. The rest is split on the phases. I can’t remember whether my solar system supplies on three phases or not but I think it does.
Yes, we have it so we use it - for sure.
The pool pump on 3 phases seems slightly more efficient when I compared them last time. The pool is also being fitted with a heat pump inverter, which doesn’t need 3 phase.
That can easily support all the things you listed and do it for a 2500 sq ft house, based on the overly conservative and outdated US NEC lead calculations.
Vs. checking a couple commodity pricing web sites - copper is currently ~$3.85 per pound.
I really doubt the motor of any "residential" HVAC unit is heavy enough for that "hundreds of dollars" to actually pan out...
To note, as mentioned, copper is not the only cost here. You also need another pole to your breaker, which adds cost. Plus busbar upgrades. And more.
The cost of termination of 3 phases is insignificant compared to the cost of the rest of an electrical system in a modern home.
It’s the better system.
What's the deal with your electric showers anyway? Surely it's more efficient to heat in a central location and distribute both a cold and a hot water circuit through the building...
Probably talking out of my ass, it's just so weird and I haven't seen it anywhere other than in the UK.
On-demand heating has the advantage that there is no thermal loss due to keeping a large amount of water (plus piping) hot 24 hrs a day.
Plus water is not wasted in waiting for hot water to arrive each time a tap is switched on.
Back in the days of Coal-fired power stations, people were encouraged to use storage hot water systems which were automatically switched on at night, so the the power stations could continue running because of the large base-load power demand.
However the modern Solar/wind generated power systems are the opposite, they much prefer loads which are only on during the daytime.
Regarding solar HWS: The cost of heating panels, piping, and installation, has meant that they are fast disappearing from the market. It's better to add a few extra solar electric panels and use on-demand HWS, either with battery storage or via grid connect.
I've just been down this route with a new solar electric plant. I had originally assumed that Solar HWS would be included, but after doing the calcs, have abandoned the solar heating panels and instead opted for a few more solar electric panels plus extra Lithium batteries. It means I have a lot more storage that can used for many different purposes.
Heat pump heater can be run when solar panel generates so much energy (energy price is low). That's a similar thing as batteries for energy use time shift.
I've seen them (my parents have one) in the UK, and lower income countries in South America, Asia and Africa.
You are very luky! The standard installed power for residential use in Italy is 220 V, 3.3 kW.
Said 50m² apartment has 16A triple-phase installed, but the breaker box is wired to be capable of safely drawing up to 63A triple-phase from the grid if I needed it.
This results in a big payoff for efficiency, however: high efficiency AC and heat pumps for water go a long way in increasing how much you can do on so much little power.
Jokes aside, I think that this ends up incentivizing an efficient use of energy. That's not so bad after all.
Induction hobs, saunas, EV chargers, to name some.
> and is the benefit outweighed by the additional cost of more copper for the additional wires?
Additional cost? You don't run that many 3-phase circuits, so the cost is negligible, and your 110V circuits require substantially higher current than ours (meaning thicker wires) so if anything I'd guess the cost for wiring a US home is on average higher than a European home.
You can add: Heat pump, electrical water heater, well pump, ovens.
I lived in both Europe (400V) and Japan (100V).
In Europe I do have an EV charging station 3-phase power with 22KW capacity at home. It does not requires anything special in term of cabling.
And it is enough to reload a Tesla in 4-5 hours, it makes EV ownership a lot easier.
Doing that with the 100V power-grid Japan is simply impossible. Most grid operator will refuse to connect 3 phases power to individuals.
Modern heat pumps in Japan with inverter is just fine with 100V or 200V for home, even for cheaper coolers. 200V hear pump electrical water heater (with tank) too.
Most houses sign up only up to 6kW or 10kW electricity, so EV charger will become a problem for family that has multiple EVs, but they will be fine with slower charging at night in most cases.
It's pain that common 100V ovens works poorly. 100V Washer dryer works barely okay thanks to efficiency. I want more 200V home appliances, like 200V 3kW kettle!
Obviously 100V would be terrible for high power stuff. I'm not suggesting that. But, 240V split-phase is more than sufficient for the vast majority of residential appliances, including EV charging.
They do too. You have lower current intensity, lower cable diameter, lower losses.
For EV charger it is even more relevant because anything inverter based has (theorically) a better efficiency in a three phases system.
The only drawback of three phase power is currently the cabling complexity. The home electrical panel need to be careful of the phases's balance.
Regarding EVs... I would assume that depends on the design. No EV sold in north america is even capable of being charged off 3-phase AC anyways, so it would require quite the redesign.
don’t cheap out on wiring. a few years after you move homes, you find some new hobby: woodworking, CNC or 3d printing, restoring pinball/arcade machines, HiFi audio, hosting LAN parties or just a few beefy gaming or video editing rigs, hot tubs, _whatever_. you can’t predict it, but there’s a good chance it’ll need power, and once you pass 1500 W in one area of the home you’re gonna either be playing the “semi-permanent 50-ft extension cords bridging the under-utilized circuits to the over-utilized rooms” (and shuffling those around with every spring cleaning) or paying 4 figures to rip out the drywall and rewire shit. just pay that up front: it’s not worth the hassle and if you have a decent realtor you’ll recoup the bulk of the investment come sale time.
due to the higher voltage in europe, conductors tend to be quite a bit thinner than in the US, to carry the same amount of energy. That being said, our electrical installations tend to be much beefier than most US residential, so a lot of copper is used. in Denmark for example standard for houses is to be fused at the roadside box for 3x~30A
Overall, it can heat things up more quickly than a typical gas or electric stove while being more efficient. And you can quickly change the temperature like with a gas stove.
-1/2 to 3/4 HP furnace fan - 3 to 5 ton AC unit
Neither of these benefit from a 3-phase motor aside from not having to swap out $10 start/run capacitors, the conductors would be #8 for 3p and #6 for split phase.
You can easily power a three-phase motor on a split-phase service with a VFD.
You can get three-phase power in certain locations at a residence, but you pay a monthly connection charge and commercial rates.
One ton of cooling is defined as 12,000 BTU/hour. The "real" value is 11966; apparently it's coincidental that it is so close to a round number. (One ton of refrigeration is 3517 watts in metric.)
The latent heat of fusion of 1 pound of water at 0°C is 144 BTU. 144 BTU/lb * 2000 lb/ton / 24 hr is 12000 BTU/hr per ton exactly.
And further, I guess there's just not much to be gained by going metric and saying "14 kilowatt AC unit" vs. "4-ton AC unit".
Tons (or, BTUs of cooling) makes more sense, because the efficiency for a given cooling amount is variable.
For efficiency, we have efficiency ratings in the SEER/SEER2 ratings.
Not the case in the UK.
Seems the power grid has the capability of delivering three phase power, but many (most?) homes in quite a few European countries don't actually have all three phases delivered.
> No matter how you put it, the US residential power grid is conceptionally lagging.
That's only the case if you believe the US is "missing out" on all that much with our split-phase setup. I don't think that's the case, really. Even for EV charging, using the 240V across the -120V and 120V lines is more or less fine. We've been doing the same thing with our electric stoves, water heaters, etc. for quite some time now.
Certainly there are some things you can do with 3-phase that aren't really feasible with split-phase, but I don't think most people living in the US care too much. It's true that those who do are probably upset about it, though!
Also consider that the US power system is trivially 3-phase! We just don't wire all those phases to homes, as we a) don't generally see the need to, b) chicken-and-egg problem suggests that most people wouldn't be able to use it anyway, since appliances made for the US wouldn't be able to take advantage of it.
[0] https://electronics.stackexchange.com/questions/625353/is-3-...
It was also free (there was a small cost, but the government subsidizes it to encourage that people switch to heat pumps).
Split phase is almost always the last mile to residential customers as it’s simpler and easier to reason about (less likely to have severely unbalanced phases too) and requires fewer conductors.
Seems the power grid has the capability of delivering three phase power, but many (most?) homes in quite a few European countries don't actually have all three phases delivered.
—-
Really all modern residential connections in Europe are 400V three phase electric power
You see if they don’t have it delivered, it’s not a modern connection. Conundrum solved!
One of my favorite things about US residential power is that 120v is far less dangerous when homeowners (or worse, kids) accidentally do something they shouldn't.
Most european houses have a single 400v outlet: right in your kitchen, for the oven (which means the oven is going to be right in front of it.) The likelihood of a child playing with it is close to nil. As for adults, the vast majority of people are taught to just flip the breaker and work on it if needed.
I promise you more people died of sticking metal into US outlets than from 400 volts.
Modern US outlets are usually shuttered, and 3 prong grounded outlets have been the required standard since about 1969. Which is over 50 years ago.
Given how many things I have plugged in on or around my desk, I’d need power strips the size of a large dog to plug them all in UK style. Whereas US they all fit in the size of a very small cat.
Also, stepping on one in the dark is a… life changing experience! Definitely pretty solid though.
Literally every single thing you've asserted is categorically false.
Earth pins have been required on outlets for nearly 50 years at this point. US outlets are also polarized, which Europlugs are not.
Shutters on outlets have been mandatory in residences and medical facilities for well over a decade.
The cable gauge is sized for the current and ambient temperature.
GFCI outlets are required nearly everywhere there is water, damp conditions (such as basements), and power tools used (such as garages and outdoors) because tools are most likely to have frayed and poorly repaired cords. Additionally all bedrooms and living spaces now require arc fault protection as a leading cause of fires is due to frayed lamp cords.
Europe still leads the world when it comes to smoking in bed as being a leading cause of house fires so I would not cast stones in glass houses.
The only shutters on outlets in any US homes I've ever lived in have been... ones I put in myself.
Many people don't notice they exist. You have to examine the outlet fairly closely to notice them but certainly any new construction is all TR receptacles now (with the possible exception of the ones very far off the floor).
Also GFCI is very common now. The vast majority of kitchens or bathrooms will have it. You'd need to find one that hasn't been renovated since the 90s, which definitely does happen, but it's becoming less common.
That is why the voltage should be lowered to 70 Volts.
The voltage shouldn't be lowered, the pins should simply be designed not to be both connected and exposed at the same time.
False
> GFCI outlets are a miracle to find
False
I don't know where some of these people come from on hackernews.
Not to mention you normally can not electrocute yourself with 400V.
400V is between two phases, you never accidentally touch two phases.
When you touch a conductor you are between one phase and the ground, meaning in 230V.
Not just conceptually == reliability is lower than that of its peers: https://www.statista.com/statistics/268155/ranking-of-the-20... (if you don't have a statista account, US is at the bottom of this list at 98.6)
State level data: https://www.eia.gov/electricity/data/eia861/
I had to upgrade my electricity meter and switch box (even though as mentioned three-phase to the house is already standard) recently in order to accommodate planned environmental upgrades.
In my neighborhood, about once a year there's a loud pop, or quiet bang, and a bunch of houses lose power. The electric company will fix it pretty quickly.
I think that it's performing selection pressure on the unlicensed squirrel electrician population.
Edit: or would that be the Free Mesons
It was manufactured in 1959!
It isn’t terribly hard to track it back if the wires are above ground.
Over here (large country in South Asia) it's three phase by default.
You can get single phase upon request, provided it's a really really small house, shop etc.
It sounds like a crossword puzzle. :)
I think in both cases, for urban and suburban areas it is standard to run the MV feeder as a normally open ring so that in case of a fault in the primary, parts of the system can be run from the other end of the ring by remotely operated automatic breakers. What I don't know is whether US systems do that at the level of the main primary only or also on the laterals.
German here. Virtually all houses built after the 60s will have at least 3x63A @ 230V (L-N) / 400V (L1-L2/L2-L3/L3-L1) AC. Individual flats/apartments/studios from before the 90s will usually have a single phase 32-40A uplink, so in a 12-unit house you'll have four flats wired to L1, four to L2, and the last four to L3 to ensure even load across the phases. More recent builds that don't have gas stoves any more will have a 3x40 connection to allow for powerful electric stoves and ovens.
How are loads balanced to phases in a standalone house?
In the end load more or less averages out across all the individual grid users.
[1] https://www.zaehlerschrank24.de/phasenschiene-kdn363f-3-poli...
My hope is that this limit forces the computer industry to put at least one cycle into actual efficiency instead of just promising a node shrink will magically fix things, since we only have a few of those left really.
I shouldn't need to run a damn space heater to play a stupid video game. At this rate, you have to think about how much video game you plan to play in your electricity budget!
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…
The US 120 volt, 15amp plugs are pretty much just for things you plug in and other light duty equipment. For anything serious, you can wire up a 120v20amp outlet or even the 240v 30amp circuit.
I think the advantage of stepping up is the filter capacitors are cheaper for the higher voltage. I think because they handle half the current.
The only advantage for 240V is higher power. All desktop PSUs top out at 1800W because of the 120V 15A limit. There are server PSU that have higher power limits that would need to use 240V to reach the higher limit.
Generally anything that has an IEC power connector will support running at 240v (but beware, you may need to flip a switch).
--------------------------------------
You have some misunderstandings in your comment.
Unless it is a very old construction or a smaller home, houses in the US as well as most of americas are provided with one or more phases derived from the secondary of a step-down transformer in Y configuration (3-phase, 1-neutral => 4 wires).
So, for a small apartment, maybe you'll get a single phase wire plus the neutral, or more commonly 2-phase wires plus neutral, up to the full 3 phase wires plus neutral.
The phases are usually 220V between then and 120 between any individual phase and the neutral connector.
Europeans don't have this convenience because the step-down transformers give homes 3 phases in a delta configuration (so, 3 phase wires, no neutral wire), so, they only have the 220V between any two-phases.
Also, split and wall ar-conditioning systems are almost universally bi-polar with a capacitor, in Europe, Asia, or the Americas. As well as most refrigerators, freezers and other similar appliances. In the past we used to have driers that would be multi-polar, but it was never very common.
It is more usual to have tri-phase motors in bigger motors, like those used in central AC units. And HVAC systems in the US accordingly will usually require an upgrade if your home is not wired with 3-phase plus neutral, unless it is a small HVAC. Electrical vehicle charges also usually require 3-phase.
People are confusing what they have the electric outlets inside their homes with what gets from the street into the distribution panel in the house. Most power outlets inside a house are bi-polar connectors (so, in europe, they can only be 220 phase-to-phase, and in the US and most of the American continent, they can be either 220 phase-to-phase or 110 V phase-to-neutral. The third connector in a domestic outlet is usually the ground, not another phase or the neutral.
The three-phases are usually split between different circuits at home, trying to ensure that the load is somewhat evenly split, but at the outlets, you'll have either phase-phase, or phase-neutral, and this is the same in Europe or America, but the americans have the flexibility to have phase-neutral dipole with half the voltage that europeans don't have.
Regarding having smaller step down transformers close to homes instead of a single giant unit, we need to remember that keeping the low-tension wires short is more efficient, and this is achieved by having the transformers closer to consumers, instead of having a giant transformer distant from the consumers.
I am not an American, and I know that a lot of things in America could be more efficient, but power distribution to residences is probably not something were europe have an edge over the US.
> So, for a small apartment, maybe you'll get a single phase wire plus the neutral, or more commonly 2-phase wires plus neutral, up to the full 3 phase wires plus neutral.
> The phases are usually 220V between then and 120 between any individual phase and the neutral connector.
I am an American - an electrical engineer in the Midwest - and I was on roofs last week after a tornado came through our town, working with the distribution panels. What you said is not correct. Homes get 240/120 nominal line voltage, or 220/110V at the load, 180 degrees out of phase, plus a neutral.
That is not the same as two phases plus the center conductor of 3-phase Y.
In industrial facilities, it's reasonably common 208V 3-phase in a Y configuration, with three wires each 120 degrees out of phase with each other. This is typically used for lighting circuits, because it's 120 phase to ground and can use commodity bulbs and ballasts. More commonly, machines will run off 480V 3-phase, which is 277 phase-to-ground.
1 - hot 1 120 v
2 - hot 2 120 v
3 - neutral
4 - ground
And to be more pedantic about it, the ground is not provided not by the power company but the ground. I have 3 lines coming from the grid to my pole, line 1, 2 and the neutral that is created by the transformer. The ground comes from my ground - a long copper wire that goes a few feet down and back up. All ground connections in the (future) house will go there. Ground is also bonded with neutral at the box on my pole.
Not some parts. It's common in all parts of Germany - and I think even common on the whole EU.
I am from Spain and living in the US and something that was shocking to me about it is that here, at least where I lived, these last transformers are hanging from poles and every now and then I can hear an explosion and it is one of them blowing up.
I have no idea but, maybe being exposed like they are here in the US makes them more vulnerable to weather conditions and that makes them explode? Or maybe it simply is that in Spain they also explode but the fact of not being that close to residences makes it harder to hear it.
With higher voltages, fewer transformers are needed. Power lines are buried, and transformers are generally larger and not exposed to weather.
I am not criticizing the infrastructure but as European (and this is something others told me) it feels weird to see transformers hanging from poles and every now and then blowing up.
And I mentioned the weather because my experience is that it usually happens during storms, it might be lightnings or tree branches but that is what I have seen.
At first I couldn't find equivalent European statistics, until I changed my search to "minutes", which is how Europe measures outages. The EU average in 2010-2014 was just over 2 hours, and as low as 29 minutes in Germany, or 20 here in Denmark.
[1] https://www.eia.gov/todayinenergy/detail.php?id=54639
[2] https://neon.energy/Neon_Data-quality_European-Commission.pd... (22nd page, figure 5)
Most power outages are broken wires. According to my utility underground wires break more often than above ground, and when they break are a lot more expensive to fix. (They are trying to make a point so this might need some salt, though i don't care enough to look up what)
Buried power lines solve most of these.
You won't find the statistic you want for Europe, as transformers don't explode enough for them to listed separately to any other fault.
I've heard for some wet construction locations they'll set up 120V split phase with two 60V legs, to keep the potential to ground smaller.
I can think of three, sort of:
1. A well pump, pumping from a high-producing well, into a tank or pond at the surface, where the pump is sized to efficiently pump somewhat less than the well’s production.
2. A pool or pond pump which, by some miracle, has been correctly sized for the system, and which, by some other miracle, is more appropriate in the application in question than an Intelliflo VSF or similar pump.
3. HVAC fans. But these are usually pretty small, and better systems usually use ECM motors.
What actually wins this fight is on the other side. A two-connector polarized NEMA 1-15 plug is a tiny, convenient, easy to use form factor that will still deliver 1400W. The experience of a normal consumer plugging in their normal junk in the US is just plain superior to the poor folks across the oceans charging their devices with BS1363 connectors that are almost bigger than the phones. And don't even get me started on Europlug.
Spend $5 or more an outlet and the plugs will work quite well.
(These kinds of things are what you should focus on if you build - materials are relatively small compared to labor and doubling your material cost on things like outlets can make a much nicer house. And if you want a UK outlet, you could get one wired up.)
Plus, I will fight anyone who suggests that 1400W is enough for a decent kettle ;-)
[0] Admittedly this was mostly included to offset the idiosyncrasies of final ring circuit wiring, but it's still better than just a big breaker.
I think your pretty spot on that most people do not need 3 phase, even in the limited cases you mentioned. =)
More power in less copper. Most items do fine with 240 volts, but high-power items like ovens and electric cars can use two or three. Also, we have the CEE 5P plugs, which look awesome and allow you to draw a lot of juice from a single point.
Czech Republic switched to 3 phase 380V in 1919. I guess the transition DC -> 110V AC -> 3 phase ~400V went quick everywhere in the world, just in US they did not do the last step.
Also the 3xT13, 3 plugs where everywhere else in the world is just one plug. [2]
[1] https://de.m.wikipedia.org/wiki/SN_441011
[2] https://hager.com/de-ch/katalog/produkt/wh22730700k-ka-eb-st...
By the way, the US nominal voltage is 120 volts. I don't know why everyone refers to 110 Volts.
You are correct about the last mile. Since single phase is distributed so often, the utility distribution engineer has a lot more work to balance things. In the UK and other networks, there is no single phase distribution.
US voltage is 120 V (240 V phase to phase), not 110 V. And while 115 V is within service tolerances specified by ANSI C84.1 (114 V to 126 V), that's not the nominal value.
For example, my laptop charger is rated for 100-240V, which is not uncommon.
Power supplies are rated for 100V because that's the voltage in Japan. Though the tolerance would probably be useful for running a really long US extension cord.
https://www.electrical4u.com/rms-or-root-mean-square-value-o...
A minority are still 115-120VAC but very few still at 110VAC or even 110VDC.
But 110V line voltage is still too common of a misconception still lingering overseas.
This can be seen in some power transformers which are built overseas with multiple primary windings intended for international use. Often these will step-up or step-down the incoming line voltage to the working level correctly using the 240V primary when 230-240V is actually powering the transformer through that winding. But when used in the USA with the 110V primary, the transformer powers the working circuit with almost 10 percent higher voltage than the engineers thought they were going to get.
Japan uses 100V and 50/60 Hz depending on where you are in the country.
Japan standardized on NTSC/60Hz well before the video game era, for both the 50Hz and 60Hz mains power regions. The frequency is decoupled from mains power frequency even though it was historically based on American 60Hz power.
This makes it about half as fast at boiling water.
https://www.aeg.co.uk/kitchen/cooking/hobs/induction-hob/ikb...
3.7kW for the main element.
Also, why would it be less efficient? Due to the distance?
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.
Edit: Wait. Are you using a frying pan to heat tee water to make it faster?
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.
Two minutes on high (1100 watt microwave output from, IIRC 1800 watt input) per cup. So usually two minutes for the one cup of I intend to drink.
Every electric kettle I’ve ever owned has a minimum volume of at least two cups. Who bother heating two cups if I’m only going to drink one at a time.
Tasmania (AU), 240v / 100amp supply to residential is standard.
All new kettles have boil-dry protection as well, so they won't be damaged with no water at all.
Not necessarily to code, consult your electrical engineer and lawyer before doing your own wiring, etc.
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.
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.
Probably about as likely as wiring up DC receptacles throughout the house. Zero.
Check with your local codes of course. Even if the local codes allow it, your building inspector may not.
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.
At least with EU induction stoves, so 230V.
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.
> US induction cooktops/stoves are almost always 240V, unless you get a little countertop burner.
EU induction cooktops/stoves are actually 380/400V.
It doesn't change much, because the amperage might be lower, I don't know.
I just wanted to add that bit of trivia :-)
For example this: https://www.emag.ro/plita-cu-inductie-aeg-hob-hood-60-cm-ikb... (in the EU), at max power can supposedly reach 7.3kW.
Edit: Checked per element, max 3.7k, more than enough anyway.
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.
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.
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.
Ignoring the UK with their 13A/30A rings for a moment, since their wiring is unique.
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.
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.
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.
> 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...
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.
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.
Breakers are probably going to be a bit cheaper and easier than opening all the walls to redo the circuits though...
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 fuse prevents that.
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?
That's massive.
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...
- 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.)
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.
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.
Has never been an issue anywhere I lived in the UK. As I understand it they have been putting in 30A/230V ring circuits as standard for 75 years now.
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 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.
You guys really need to get on the solar panels, though.
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.)
> I'm struggling to understand how the British grid works
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.
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.
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).
Have a look here: https://www.diydoctor.org.uk/projects/cablesizes.htm
Being compelled to wait two minutes more to boil a kettle for a cuppa would be enough to provoke an armed rebellion.
Not even sure I'm kidding.
(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.
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.
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.
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.
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.
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.
Part of the reason I emigrated.
https://www.canadianhomeinspection.com/home-reference-librar...
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.
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.
Fuses/breakers are ultimately about heat control. They can run "indefinitely" at their rated amperage, but can support short, higher loads.
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.
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.
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.
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.
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.
A kettle is fine at a full circuit load for under 3 hours.
If I wanted a British kettle in the US I'd wire up a 6-20R, buy a British kettle, and swap the plug.
In practice, NEC code likely prohibits you from doing this.
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.
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.
A furnace is what you use to make clay set into a pot!
https://www.channel4.com/programmes/guy-martins-great-britis...
> 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.
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’ve only seen one in person myself. More common is a fridge that can dispense hot water (!!)
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:
* https://www.ontario.ca/laws/regulation/r04023
An exception is given for dish— and clothes washer outlets.
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.
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 kid, but there's something about "fresh" water probably?
Also it will reboil after a certain amount of time.
Always use freshly drawn (filtered if possible) cold water in the kettle. Tea loves oxygen as it helps the flavour develop.
Most of us are guilty of the following... looking at the kettle seeing there is some old, used water in there and simply re-boiling.
If you keep re-boiling the water in the kettle, it loses all of its oxygen and you’ll be left with a really flat cup of tea.
If you boil the kettle with fresh water, you’ll have a delicious cup of oxygenated tea that tastes divine.
https://twinings.co.uk/blogs/news/how-to-make-a-cup-of-tea-p...
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.
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.
So I don't think the science backs this up.
Make tea such that you enjoy it. Same as coffee.
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.
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.
https://insinkerator.emerson.com/en-us/shop/insinkerator/ins...
If you're dead-set on "reoxygenating" your boiling-hot water, pour it from a slight height such that air bubbles form and re-aerate the water.
<https://www.engineeringtoolbox.com/air-solubility-water-d_63...>
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.
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.
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.
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.
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.
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.
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.
Because it is better to boil the right amount of water to the precise temperature when you need it, as it takes virtually no time.
=-=-=
Question #1: Can we get 3 kilowatts of power out of some lithium ion batteries?
There are high-current versions of lithium batteries. Conveniently, they're widely available because they're used for vaping.
I found a battery that looks reasonable (https://www.18650batterystore.com/products/molicel-p42a). Its stats: 4200 mAh capacity, 3.6V nominal, 45A continuous discharge, and retail cost $4.99.
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.
=-=-=
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.
=-=-=
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.
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.
In the UK I put the water on then while it’s boiling get a mug and tea bag and then the kettle is boiled very soon after.
In the US I generally wonder off as the kettle takes a couple of minutes longer.
https://www.homedepot.com/p/Rheem-Performance-36-kw-Self-Mod...
/s
3000 / 230 = 13.04
3000 / 240 = 12.5
We fit 13A fuses to the plugs of kettles. At 230V the tolerance would be too close.
Whereas in reality, a kettle designed to be 3kW at 240V would only be 2.755kW at 230V, or 2.520kW at 220V.
You'll often find the latter pair of number printed on the base of the kettle. i.e. 2520-3000W at 220-240V.
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.
The difference is 2 minutes on the boil time of 1L.
* https://www.youtube.com/watch?v=7yRGvMgieEU
Edison originally purchased others' dynamos, especially Wallace-Farmer, which was 110V (DC):
* https://americanhistory.si.edu/collections/search/object/nma...
* https://en.wikipedia.org/wiki/Moses_G._Farmer
So Edison's long-legged Mary-Ann was also 110V:
* https://www.collectorsweekly.com/stories/82967-thomas-edison...
* https://edison.rutgers.edu/life-of-edison/inventions?view=ar...
* https://americanhistory.si.edu/collections/search/object/nma...
Light bulbs in the early 1900s were first designed for lower voltages, and the grid slowly raised things over time, but at some point they couldn't go any higher because it would start blowing things, so they were 'stuck' in the 110-120V range.
50 Hz is about a G, and 60 Hz is about a B-flat. Video comparison: https://youtu.be/pMtn-loUrg8
Are they, though? With modern appliances, power requirements are going up and 110V is struggling to keep up. One example would be an induction hob.
I know that technically US homes can access 230V but they aren't wired for that, probably 99% are wired just for 110V except for maybe a few special lines.
The reason for gas in the US is because people like it. It's been seen as upscale for decades to have a gas cooktop. It also helps that gas water heaters don't require electricity and work in an outage. Our residential natural gas distribution network is extensive and reliable, and it's pretty straightforward to use the same appliances on propane for people out in the sticks.
Things like lightbulbs and TVs and computers and refrigerators are using less power than ever before.
Of course, if people are buying electric cars or replacing gas furnaces with electric heat pumps, then you're right on that side of things.
Are they, though?
Lightbulbs, sure, we won with LEDs.
But TVs, especially the huge, high brightness ones we have nowadays? And with the extra computing needed?
Computers, same, I only see power usage going up. I mean PCs, we're not comparing things with mainframes here :-)
Refrigerators: are they really more efficient?
Now add: heat pump, induction stove, electric oven, more powerful AC, humidifiers/dehumidifiers, etc.
And compared to the age of the Pentium 4 with its 100W+ TDP, laptops now outsell desktop computers by a long way.
(I would agree that things like high-end gaming GPUs are using more power than ever before - but they're also a much smaller % of sales than ever before)
According to the internet a CRT TV used to use about 100W, while a big LCD TV can use more.
Regarding desktops, don't forget that these days we have many more electronic device in a home. Smart speakers, home media devices, consoles, etc, etc. Electronics probably use, in aggregate 5-10x what the old family PC used to use, I'd imagine.
To change my gas stove/oven back to 240v induction would be a 15 foot run of romex, a new outlet, and probably an updated circuit breaker. Possible for a DIYer to do.
Older houses might have a dedicated 240 plug for the dryer and the stove if they're not natural gass, but for everything else there are plenty of homes full of ungrounded 10 amp 120v circuits.
And yeah, my house is full of 120V circuits, but once again the house has 240V at the panel and could run 240V anywhere in the house if needed. As you pointed out, they probably do have a 240V plug for the dryer, ergo they've got 240V service at the property, so they could wire the kitchen if there's no wiring already. Once again, practically nobody has only 120V service at their home.
US Version: https://www.bosch-home.com/us/productslist/cooking-baking/co...
UK Version: https://www.bosch-home.co.uk/product-list/cooking-baking/hob...
Largely they have the same power output. While the total power available is actually higher for the US version at 12kW versus 11.1 kW for the UK version. That is because the US version needs to be on a 50 amp 240v circuit versus the max 16 amp circuit for the UK version.
Even this Bosch one: https://www.bosch-home.co.uk/product-list/cooking-baking/hob... Which clearly calls out 400v 3 phase has a lower power output at 7.4 kW.
The max output to a single pan/pot typically is going to max out around 3.3-3.7 kW. I don't know the exact reasoning behind that but I assume it might cause issues with cookware if you go much higher than that.
Assuming 120v loads are split reasonably equally between each leg of the 240v phase, the load will mostly be on the 240v circuit because both legs are connected in series. The neutral back to the transformer is only used to carry the difference between the 120v load on each leg of the phase, and also to keep the system grounded.
I guess if you had a panel close to load capacity, as well as a single very high amp 120v device, the transformer could enable some more capacity by ensuring the load was distributed equally between the phases. However at that point a service upgrade would probably be necessary anyway based on the load calculation rules in the code. Also high amp 120v devices are quite rare as far as I know, so I was wondering why you went with this unusual setup.
(from the wiki: https://en.wikipedia.org/wiki/Electrical_wiring_in_the_Unite...)
UK fixed wiring circuits, unlike those found in almost all other countries, make widespread use of ring circuit designs, as well as radial circuit designs often seen in other countries. (This was one of the recommendations of the Electrical Installations Committee, convened in 1942 as part of the Post War Building Studies programme, which in 1944 determined that the ring final circuit offered a more efficient and lower cost method to support a greater number of sockets.[6]) It continues to be the usual wiring method for domestic and light commercial socket and device wiring in the UK. Lighting circuits, which typically have lower power requirements, are usually radially wired, confusingly sometimes called "loop" wiring.
Safety was one significant concern. 230-240V is more likely to stop a person's heart. 220 is available in most US homes for specific cases where it is more practical.
Speaking from experience, I don't think it is uncommon for a person to have been electrically shocked at some point in their lives --- often when they were a child.
Wire insulation deteriorates over time. Rodents like to chew through it. Water can find it's way in through plumbing or roof leaks. Higher voltage is more likely to start a fire in these instances.
The total number of fires of electrical origin in the EU is estimated to be 273,000 per year.
Fire departments responded to an estimated average of 46,700 home fires involving electrical failure or malfunction each year in 2015–2019.
https://www.europeanfiresafetyalliance.org/publications/whit...
https://www.nfpa.org/News-and-Research/Data-research-and-too...
What keeps a kid from sticking something metal into it?
UK plugs and sockets are really, really, really safe. Except to stand on.
You can try pushing with something like a screwdriver (to test for live) and it's hard to pivot the plate (feels like it needs both pins to pivot), and a non round tool snags on the plastic cover plate.
On the other end, in India I saw a power strip that would accept EU, UK, or US plugs. I took one look and refused to get close, but someone else plugged my laptop in and it worked. (everything got 240 volts, which my laptop power supply was fine with)
https://electronics.stackexchange.com/questions/469913/compu...
In the early 1980s, my dad found an old valve keyboard / organ thing at some jumble or car-boot sale that probably dated at least from the 1950s, and being curious I used to regularly take it to bits. One thing that was weird is that there was an input voltage selector on it, but it was a round thing with contacts arranged in a circle and a plug that would bridge one contact to the centre contact. The range of input voltages was 60VAC to 240VAC, and there were probably 10 or 12 different voltages in that range. Unfortunately, this was also how I destroyed the keyboard part (but not the separate valve amplifier that I continued to use for at least another decade) because the 60VAC was next to the 240VAC and I accidentally bridged it to 60VAC and fed it 240VAC. All the valves were powered at 4x what they should have been and there was a bang and nothing worked after that. In retrospect, I should probably have kept it as probably only a few valves took the brunt of power surge, but even then valves were hard to get hold of and these weren't all the same (my memory is fuzzy, but there were probably 30+ valves in the keyboard, I only pulled a few to look at them and they were obviously different), so we just decided it was something that didn't need to be repaired.
But anyway, long story aside - there must have been some demand for such a wide range of input voltages for the power supply, or they wouldn't have come up with a selector switch with so many possible options.
It's just a standard "Emacs vs VIM" flamewar.
Though it is crass, I'll say it. A silver lining to the tremendous infrastructure damage caused by world wars in Europe is that ossification was interrupted.
/s
That's because there is no winner. Nobody is doing something in the US that is impossible in Europe, or vice versa. There are upsides to both approaches, and different trade-offs, but everyone is getting enough power.
Pretty much exactly why the UK didn't.
What, you say? The UK uses metric, right? Yes, in much the same way as the US does.
Officially, the US gov't stance is metric. And in technical areas as well as much of the consumer space, metric is everywhere. What isn't really changing is layperson preference for units. People are comfortable with feet, yards, miles, Fahrenheit, etc. Just like the UK still using miles, and many normal people measuring weight in stones.
Inertia is a pretty important consideration, and not invalid. Imagine trying to convince the UK to drive on the correct side of the road at this point. ;-)
Or, even more curious, why are so many British authorities so bizarrely (to the point it's funny) protective over electricity, fining people and threatening to call police on people who try to charge their phones in train stations, for example?
It's a pain they are not the same as the rest of Europe, but what is cumbersome and over-designed about UK plugs?
Follow up question, why Swiss plug needed to be so close to the rest of Europe, but different anyway? (same distance between the 2 pins, but the pins are a bit thinner and the ground is in the opposite way).
The size is definitely cumbersome. Look how much bigger they are than US/EU/AU plugs, basically any other countries plugs.
I'd call having a fuse in the plug itself over-designed.
> Follow up question, why Swiss plug needed to be so close to the rest of Europe, but different anyway?
I have the same question about AU plugs. Literally the same as the US plugs (newer ones that don't have one side larger at least), just at an angle.
Personally, I'm quite happy that all my lower power devices with relatively thin power cables are protected by a 3A fuse. There's no risk of causing those cables to catch fire if there's a fault that draws 20A, which isn't enough to blow the 32A breaker on that ring.
How much difference it makes in practice though? Pretty sure that if I short the power at the device end of a 5A cable, the 32A breaker would blow before the cable caught fire. But I'm happy not to depend on that.
Seems to me it's somewhat like having an additional seatbelt for your head, which might protect against whiplash but isn't justified by the inconvenience.
>I'd call having a fuse in the plug itself over-designed.
I wouldn't. A UK mains circuit typically has a 32A breaker. Pulling that much current through an appliance that's designed for a fraction of an amp or a cable that's designed for 3A is obviously a very hazardous fault condition. Some appliances have a built-in fuse, but many don't and that still doesn't offer the same level of protection as a suitably-sized fuse in the plug.
How much does a folding plug fold? Look how minimal this[0] is, I've never seen any UK plug anywhere close to that size.
> I wouldn't
Any reason the fuse couldn't go in the socket instead?
[0] https://i0.wp.com/www.cablesgo.com/wp-content/uploads/2018/0...
Because changing the fuse in a socket just because you're unplugging a lamp and plugging in a kettle would be very stupid. With the fuse in the plug, you have the correct fuse in every plug.
That's my main problem since I travel a lot, or used to at least.
Aside from old-style type-C plugs (two prongs) in old sockets, I've never seen an EU plug work itself loose in a socket, let alone slip out of it. Usually, there's the reverse problem: they're difficult to unplug, even when you want to.
In the US, the cord would likely pull out of the wall, safely.
What hairdryer? British building regs restrict you to an isolated "shaver" socket in the bathroom which takes different plugs. You can't drop a hairdryer in the bath unless you play silly games with extension cables.
So basically we could use less copper, have safer homes, and simplify power supply design since we (and a handful of other holdouts) are basically the only countries using 100-120 VAC rather than 210-230 VAC, which would lower costs and reduce waste.
My European 50m² apartment has two.
In the UK, this is not allowed because 240V is not a good idea in bathrooms.
They really are just for shavers though. You can't run anything high power without blowing the fuse. I believe Americans often use hairdryers in bathrooms. We definitely can't do that.
That said, we do have electric showers in UK bathrooms but legally those need to have a kill switch installed.
>Explain me with calculation.
As with many things related to technology, decisions are very often made for seemingly arbitrary (or political, or economic, or competitive-advantage) reasons, not because of some calculation that was done that proved a decision optimal.
Where I live (Brazil) is commom to have both. In the big cities you will find 110v and outside that you are more likely to find 220v. And yes, it is a pain if you move from a 220v city to a 110v one. But besides that most people don't care about having 2 standards.
For anyone interested there is a semi-relevant TechnologyConnections video[0] where he discusses the popularity of kettles as way to heat water in the US.
I've never found a technical answer for the 50Hz vs 60Hz question. It does seem to be an arbitrary standard.
Then when Europe was standardizing, they wanted to be all metric, and 50 was close enough to 60 and still could become 100 by doubling.
I don't know, those are just pure guesses.
I think when you come from the engineering/tinkering side of things, you like units with easy integer fractions (12 inches in a foot is really easy to work with at human scale). When you come from the science side of things, you like easy decimals and that's why metric wins there.
Which country are you talking about?
It used to be the continent used 220V, and the UK used 240V, until we standardized on 230V.
The UK defines this as 230V -6% +10% (i.e. 216.2V – 253.0V), and nominal supply is 240V
The continent defines this as 230V -10% +6% (i.e. 207.0V - 243.8V), and nominal supply is 220 or 230 by region.
We called this harmonisation - in reality it's more like agreeing to disagree. We just fudged the tolerances until everyone was happy.
(To put some context around this - most sites don't receive nominal supply. The actual voltage delivered depends on your distance to the local substation. Typically they over-deliver such that sites closest are a little over, sites furthest are a little under. If they actually delivered ±0%, sites at the edge of their network would be further from nominal. So end-user equipment should be built to expect variation.)
I believe ±10% was the traditional definition, so they just trimmed a little off the top end so it strayed less from Europe's definition - but not enough to actually affect nominal distribution.
Uh huh, here's an idea, go ahead and test that out for yourself!
I don't know where you are, but in the US a walk-behind trencher rents for under $500 per day [1] [2] [3] [4].
[1] https://www.sunbeltrentals.com/equipment-rental/earth-moving...
[2] https://www.compactpowerrents.com/rental-equipment/trencher/...
[3] https://www.compactpowerrents.com/rental-equipment/trencher/...
[4] https://www.compactpowerrents.com/rental-equipment/trencher/...
More common where? Your main service panel is 240V. Do you only have a single 120V circuit feeding your garage?
Now, I'm going to go talk to My Fellow 'Mericans about continuing to not use the metric system.
If memory serves, Thomas Edison used a 110v DC power supply to create a system of electricity for people. Meanwhile, Nikola Tesla invented the three-phase 240v Alternating Current (AC). Tesla was clearly a man ahead of his time (even by today's standards).
tldr; Europe's grid is vastly superior to America's.
That's needlessly inflammatory. Both the US and UK governments have numerous electrical standards and regulations designed to keep people safe despite unsafe power levels in residential wiring. You might argue that they aren't doing enough in this regard, but to say they only care about saving metal just isn't true.
[1] https://www.dailymail.co.uk/news/article-12042495/Italian-gi...
I go even further on trying to save aluminum in my wires by not using any aluminum wires. Aluminum wiring is pretty rare in the US and largely considered a nightmare to work with.
Yeah, you basically only find aluminum wiring used today for the feeder, and for circuits larger than 60A. And that's mainly due to cost, copper is pretty expensive.
Safer? Why?
I meant less safe.
edit: after a quick research i thing the reason is the socket: https://www.everyworks.com/reasons-why-your-singapore-electr... we don't use this, we have a small hole inside ours and it's impossible to touch the live while the plug is connected
edit: can't reply to the child comments, maybe there's a time limit, i'll answer here. i have no experience with the british plugs, if you say it's impossible i believe you. i don't understand, though, how does this happen to the person from the top message.
It is possible to get a very mild shock from the plug contacts if the input capacitors of the appliance haven't fully discharged. This shouldn't happen with properly-designed appliances, but it's very unlikely to be dangerous if it does happen.
Here’s a video by Tom Scott about why UK plugs are safer: https://youtu.be/UEfP1OKKz_Q?si=f8UxqwhN4tmYxFMk
Here in Australia we have 230V, and getting shocked is not at all common - we have very strict electrical standards for both installations and devices, residual current devices (GFCI equilivalents) now required on every single circuit, everything either has a proper ground or is double-insulated (unlike the US sockets here without a ground pin are very uncommon because you can’t plug a lot of devices in to them) etc.
There was a possibility where you could pull the plug out very slightly and slide something like a knife in between the plug and socket and touch the active and neutral pins, so the standards were changed many years ago now so compliant plugs now have insulation on the live and neutral pins for the first half of their length (see an example plug here - https://au.rs-online.com/web/p/power-cords/0321168 ).
Another problem: Some of the plug/socket combinations were fairly loose. It wasn't a tight fit. So if you're ironing, it was not unusual for the plug to be partially out of the socket.
Interested in the answer which I don't have.
That said, UK is wired to the continent, which runs at 230V, 50 Hz.
Everyone runs at the exact same frequency (same fluctuations) at any moment across the whole continent for technical reasons. (edit: UK is actually not synchronized with the continent, I didn't know that either).
I guess having the about the same voltage as the rest of the continent is at least convenient (edit: apparently it's not exactly the same?).
So I guess the question is US vs the European continent.
Curious about the rest of America (North and South).
You are right about the european grid, it is synchronized
In the UK at least it's from around 216 to 253 volts. Mine is sitting at 249 now.
Brazil is a bizarre mess of 127V single phase in most of the south and 220V single phase in the rest. They are supposed to use euro-style grounded receptacles but often have installed euro and NEMA bi-compatible plugs at 220V or 127V. A lot of 220 circuits only carry 8-10A.
Argentina uses the Australian style receptacle with 220V 50Hz.
I'm not sure about the rest of South America but I think Uruguay and Paraguay are compatible with Argentina and the rest are on 60Hz and generally 220V.
I'm surprised nobody mentioned Japan, and its varied system.