Anyone Else Outraged About 3 Phase?

[james_s]

I was shocked when somebody wrote that it is normal to have 200A single phase supply to the house  These are ridicoulous currents for domestic supply... I just cant understand why they are not using 3 phase supply in america

As others wrote, in europe every building has a 3 phase power supply, here most common main fuses are 3x20A or 3x25A. Now compare that to single phase on 110V   
And everything is so simple, as you have the same voltages everywhere. 230V/400V in your own house/worklab, same in industry. In industry most of equipment is on the same voltage level, of course some big motors (1MW) are running on 6kV.
The beautiful thing is that i can test any industrial equipment anywhere i am...

200A 240V service is the standard for houses in the USA and has been for around 40 years, I don't think you can even install anything smaller in new construction. Larger houses sometimes have 400A, especially in areas that do not have natural gas service and thus need a lot of power for electric heating. I have even seen a few very large houses with 600A service, the sort of places that would qualify as mansions, these are still single phase. I don't think it really matters though, for 99.9% of the population they plug a device into a wall socket, it works and they are happy. They don't know anything about phases and they don't care, nor have any reason to care. If I were designing the whole system from scratch then 3 phase would be a natural choice, but it is all built upon decades of legacy equipment. The USA electrified very early relative to much of the world, so we were building upon the oldest and most primitive system. Countries that started later had the benefit of starting out with more modern technology and not having to worry about compatibility with existing infrastructure. You see this sort of thing all over, not just in power.

[drussell]

I was shocked when somebody wrote that it is normal to have 200A single phase supply to the house  These are ridicoulous currents for domestic supply... I just cant understand why they are not using 3 phase supply in america

As others wrote, in europe every building has a 3 phase power supply, here most common main fuses are 3x20A or 3x25A. Now compare that to single phase on 110V   

It isn't single phase 120V!...   

It is 240V centre-tapped to 120-0-120, so the main breaker is 2x200A, so that is 400A total available at 120V or 200A total at 240V.

Apparently we usewaste far more electricity on average than you folks do.   

[james_s]

Thankfully, you can't put a fork or a skewer in ours..

No, but you can open the shutter with a screwdriver into the ground socket and insert stripped wires into the other two sockets.  Removing the screwdriver will hold the two wires in place.

US code now requires "tamper resistant" receptacles in homes here too, they have shutters similar to the UK sockets. I don't like them personally, they cost as much as commercial grade stuff but are built like the cheap builder grade devices and sometimes it's hard to get some plugs to go in properly. It's easier to just not poke stuff into wall sockets. The live slot is small enough already that most metal objects like forks and coins and such won't go in anyway, stuff like hairpins and straightened paperclips, well a determined child will figure out how to open the shutters on UK receptacles anyway. I tend to view it as evolution in action. I've never known anyone who has known anyone who has had a kid electrocuted, it's pretty low on the list of household risks.

[james_s]

It isn't single phase 120V!...   

It is 240V centre-tapped to 120-0-120, so the main breaker is 2x200A, so that is 400A total available at 120V or 200A total at 240V.

Apparently we usewaste far more electricity on average than you folks do.   

North American houses are gigantic by European standards. My 2200 sqft 3 bedroom split level is very modest, it was considered a starter home when it was built in 1979. Even the tiny single floor houses that sprouted up like weeds in the post-WWII building boom are bigger than typical European dwellings. Geography that has historically offered vast amounts of space and abundant resources led to a culture of large (by world standards) homes.

[chris_leyson]

Anyone Else Outraged About 3 Phase? Short answer is no. If you really have a justification for needing a 3-phase supply it's probably already there, either overhead lines or underground, you just have to pay for the connection. An engineer would have done his or her homework and used some common sense whereas a troll would throw a hissy fit. Just my 2cent worth.

[elekorsi]

It isn't single phase 120V!...   

It is 240V centre-tapped to 120-0-120, so the main breaker is 2x200A, so that is 400A total available at 120V or 200A total at 240V.

Apparently we usewaste far more electricity on average than you folks do.   

North American houses are gigantic by European standards. My 2200 sqft 3 bedroom split level is very modest, it was considered a starter home when it was built in 1979. Even the tiny single floor houses that sprouted up like weeds in the post-WWII building boom are bigger than typical European dwellings. Geography that has historically offered vast amounts of space and abundant resources led to a culture of large (by world standards) homes.

True, our styles of construction are very different. We build houses much more energy efficently. Nowadays it is standard to have 15-25cm or even more insulation on the outer skin of the house, with a lot of details to minimize the losses. We dont use electricity to heat directly, but instead use natural gas, heat pumps or wood for heating. We use very little energy for cooling also, i don't even have an AC and i dont need it even in the middle of the summer when there is 30-35°C. I heat the house with wood gasification boiler (with lambda control), coupled with 2000l heat acumulator, meaning that i use minimum electricity for the heating (only the consumption of boiler fan, water pumps and electronics)

[electromateria]

I'm not paying a single dollar of tax money until some 3 phase power comes zipping on through to my location.

WHOS WITH ME!!

[madires]

It is 240V centre-tapped to 120-0-120, so the main breaker is 2x200A, so that is 400A total available at 120V or 200A total at 240V.

Over here a single-family home has usually 35A (3*35A at 230V) or 63A (3*63A at 230V) main breakers based on the local power company. An apartment building with two or three flats mostly has 63A main breakers and 35A breakers for each flat.

[themadhippy]

well a determined child will figure out how to open the shutters on UK receptacles anyway

In the uk the kids are assisted by the do gooders who tried to make everyone fit "safety "covers to sockets

[drussell]

I'm not paying a single dollar of tax money until some 3 phase power comes zipping on through to my location.

Good luck with that...

[Cerebus]

The USA electrified very early relative to much of the world, so we were building upon the oldest and most primitive system.

I love these little myths Americans tell themselves about doing things first. 

The first general power station in the world is generally accepted to be in Godalming, Surrey, England. It was commissioned in 1881, and by 1882 8-10 households were connected up. The Holborn Viaduct electric light company started up the same year, and rapidly proceeded to where it had 1000 light bulbs on its supply.

However, I'm sorry to report that the French beat us to as to the first public use of electricity, in lighting up L'Avenue de l'Opera ten years earlier in 1878. The Germans (Siemens) were into the game pretty early too.

Edison's Pearl Street station in New York went into operation the same year as the Holborn Viaduct one in London (also an Edison owned plant), so America was electrifying at the same time as the rest of the world (those bits likely to electrify back in those days), not very early relative to the rest.

In 1887 an 800 kVA power plant was built in Deptford, East London, completed in 1891, it supplied central London over a 10 kV line, believed to be the first use of a high voltage transmission line.

Small, single household private supplies existed before this of course, I'm just talking about public utilities. In the case of private and early public supplies there was little standardisation, which is the point at which systems tend to build inertia.

So there's no special history that forced the US to live with existing standards because they started earlier than anyone else. Everybody was building on "early and primitive" systems at the same time.

[TimFox]

Thankfully, you can't put a fork or a skewer in ours..

No, but you can open the shutter with a screwdriver into the ground socket and insert stripped wires into the other two sockets.  Removing the screwdriver will hold the two wires in place.

US code now requires "tamper resistant" receptacles in homes here too, they have shutters similar to the UK sockets. I don't like them personally, they cost as much as commercial grade stuff but are built like the cheap builder grade devices and sometimes it's hard to get some plugs to go in properly. It's easier to just not poke stuff into wall sockets. The live slot is small enough already that most metal objects like forks and coins and such won't go in anyway, stuff like hairpins and straightened paperclips, well a determined child will figure out how to open the shutters on UK receptacles anyway. I tend to view it as evolution in action. I've never known anyone who has known anyone who has had a kid electrocuted, it's pretty low on the list of household risks.

We just added a room to our house, and these 120 V "tamper-resistant" receptacles were installed (per code, I assume).  They work fine with a three-prong plug, but double-insulated appliances usually have two-prong polarized plugs (neutral blade wider than line blade), and the shutters don't work well with them.  To solve that problem, I use UL-listed circuit-breaker-protected three-prong plugged outlet strips, since the outlets are never in the right place anyway.

[Cerebus]

We just added a room to our house, and these 120 V "tamper-resistant" receptacles were installed (per code, I assume).  They work fine with a three-prong plug, but double-insulated appliances usually have two-prong polarized plugs (neutral blade wider than line blade), and the shutters don't work well with them.  To solve that problem, I use UL-listed circuit-breaker-protected three-prong plugged outlet strips, since the outlets are never in the right place anyway.

Yes. It's a bit odd, and frustrating, to have a code that dictates that and still have two prong connectors everywhere. It was never an issue here, because the requirement for shutters came well after the move to 3 pin sockets that didn't physically accept any earlier two pin connectors. Shuttering was always a possibility, and by the time it was mandatory the necessary 3rd pin was a non-issue, it was already there on every cable. It's the norm here to have a 3 pin plug even on cables for double insulated equipment that doesn't actually use the redundant earth pin.

[langwadt]

Someone else has noted that it's normal to take the three phases and neutral down the whole street and tap different phases at different points for different building's supplies. It's quite possible that your next door neighbour is on a different phase - something to bear in mind if you're having a party in the garden and someone decides to throw an extension cord over the fence to power the disco lights from the neighbour's mains, while you power the music from your house's mains.

I once worked in a Lab where we discovered that adjacent workbenches were on different phases! 

415V 3 phase ceiling drop to the end of each row of three benches and... 

so what's the issue? each bench gets a phase and thus a fuse

[james_s]

I've discussed all of this stuff at length with an engineer friend of mine in the UK and over the years we've come to the conclusion that there is no clear winner. The UK and various European systems have some advantages and the US system has other advantages, ultimately the important part is that all of these systems work, all of them are reasonably safe, all are capable of powering all the sorts of loads one is likely to have in their homes. I like the fact that there are still significant differences between them, in a world that is more and more globalized and homogenous. Very few of the classic brands of appliances are around anymore and stuff like a TV or food mixer is essentially identical and made in China no matter what part of the world you buy it in.

I like the UK plugs because they are chunky and sturdy, they hold the plug firmly in the socket even if it's a heavy old style wall wart and the plugs (that I've seen) are all right-angle so furniture can be placed close to the wall. The fused plugs are also a nice touch, it's one more protective device in the chain.

On the other hand the plugs are bulky, British power strips are massive things for the number of sockets on them compared to ours. The huge plugs are used even on light duty cords on compact and very low draw devices like mobile phone chargers. They also tend to land with the prongs pointed straight up if you leave them on the ground. Even though I have only a few devices with British plugs, I've still managed to step on one in my socks which does not feel good, though it's not as bad as TO3 transistors. 

[james_s]

The USA electrified very early relative to much of the world, so we were building upon the oldest and most primitive system.

I love these little myths Americans tell themselves about doing things first. 

The first general power station in the world is generally accepted to be in Godalming, Surrey, England. It was commissioned in 1881, and by 1882 8-10 households were connected up. The Holborn Viaduct electric light company started up the same year, and rapidly proceeded to where it had 1000 light bulbs on its supply.

However, I'm sorry to report that the French beat us to as to the first public use of electricity, in lighting up L'Avenue de l'Opera ten years earlier in 1878. The Germans (Siemens) were into the game pretty early too.

Edison's Pearl Street station in New York went into operation the same year as the Holborn Viaduct one in London (also an Edison owned plant), so America was electrifying at the same time as the rest of the world (those bits likely to electrify back in those days), not very early relative to the rest.

In 1887 an 800 kVA power plant was built in Deptford, East London, completed in 1891, it supplied central London over a 10 kV line, believed to be the first use of a high voltage transmission line.

Small, single household private supplies existed before this of course, I'm just talking about public utilities. In the case of private and early public supplies there was little standardisation, which is the point at which systems tend to build inertia.

So there's no special history that forced the US to live with existing standards because they started earlier than anyone else. Everybody was building on "early and primitive" systems at the same time.

Well, I don't know then, I wasn't around back in those days but I'm sure there are historical reasons for it. Geographically the US is over 40 times the size of the UK, meaning things are far more spread out, there is far more infrastructure required per individual home, especially in the vast rural areas so it is far less cost effective to replace existing infrastructure. Maybe culturally we are also more resistant to change, I don't really know. Suffice to say electrical infrastructure we use today is largely compatible with what was being installed 100 years ago, the same ancient plugs will still fit in a the receptacles in a modern house, 100 year old light bulbs will still screw into modern sockets, the voltages are roughly the same now as they were then, and much of it was backward compatible with the DC systems that came even earlier. The lower voltage offered significant advantages for incandescent lighting which was the primary use of electricity in those days, later the proliferation of larger loads meant that 120V (or 110 or whatever it was at the time) was no longer adequate so the 240V split phase was introduced, maintaining compatibility with existing 120V loads.

[Circlotron]

In my parents home even my bedroom had 3x16A 3-phase outlet 

Cool!  Could someone post a pic of that? I'm familiar with industrial strength 3-phase outlets but never seen a domestic one here in Australia. I have 3-phase at home. Cost me an extra AUD$200 when the house got built in 1994. Instead of 1x100A I got 3x60A. That's what would fit in the underground conduit from the street to the house. Would have much rather had 3x100A of course. I was involved with 3-phase induction motor SCR soft starters / power savers at the time. Never actually got around to using it at home. Nowadays general power is on one phase, aircon and solar is on second and lighting on third. 240/415 here.

[Cerebus]

Geographically the US is over 40 times the size of the UK, meaning things are far more spread out, there is far more infrastructure required per individual home, especially in the vast rural areas so it is far less cost effective to replace existing infrastructure.

It's always the size thing with you. Anyone would think you were compensating for something. 

There are other big places too, Russia for instance, which certainly got into electricity back in the Tsarist days. That other places don't seem to have suffered the same inertia points to some difference. One thing might be that the US has traditionally leaned on private enterprise, where in other places there's been more state involvement. In the early days of electricity in the UK not only was it officially licensed, but there were clauses in the licenses that allowed local government to take over the operations if the electric company failed commercially - that points to a more centrally planned approach from the start. Perhaps some central planning is necessary for evolving the system and not merely building on what you've already paid for and own.

[S. Petrukhin]

In Russia, all apartment buildings have a three-phase connection. If the apartment has powerful equipment, such as an electric stove, it receives three-phase power. Detached houses have a 3-phase line next to each other and are connected to the phases in turn. Start all 3 phases only a matter of replacing the electricity meter and performing the work.

[Circlotron]

This food fight about whether 120VAC either side of a centre tap is 1 or 2 phases; this is my take on it. The number of phases is equal to the number of different zero crossing points with respect to neutral. So you may have 6 different lines but only 3 different zero crossing moments so I say that's 3-phase.

With 2 sinewaves 90 deg apart you have 2 different zero crossing points so that's definitely 2-phase, but a single phase transformer with a centre tapped secondary does not produce two different zero crossings.

[james_s]

It's always the size thing with you. Anyone would think you were compensating for something. 

It's not a competition or superiority thing, it's an objectively true fact. The US (and Canada) are geographically huge with vast expanses of sparsely populated land with a huge percentage of the population clustered on the coasts. The scale of things is something that people in many European countries seem to be not fully aware of going by comments that come up over and over, and why would they be? There are any number of countries on the other side of the world that I have no idea how large they are, how the population is distributed or what reasons contributed to the design of their infrastructure.

I can only speculate on the reasons things were done the way they are, probably none of them that you'll be happy with other than "because we're stupid out here", maybe we just prioritize things differently. It is what it is, it evolved the way it did, and it's far too entrenched to change it now and not widely perceived as something that needs changing. We have so much crumbling ancient infrastructure that it would already cost trillions of dollars to replace all the stuff that really needs  replacing, we're not going to replace stuff that works just because there are improvements that could be made today.

[james_s]

This food fight about whether 120VAC either side of a centre tap is 1 or 2 phases; this is my take on it. The number of phases is equal to the number of different zero crossing points with respect to neutral. So you may have 6 different lines but only 3 different zero crossing moments so I say that's 3-phase.

With 2 sinewaves 90 deg apart you have 2 different zero crossing points so that's definitely 2-phase, but a single phase transformer with a centre tapped secondary does not produce 2-phase.

6 different lines? You'd never see such a thing. There are only two basic configurations here, and both start with a 3 phase medium voltage (usually 7200V/13500V). One of these configurations is 3 phase 120/208V using 3 transformers or a single 3 phase transformer delivering 3 live phases and neutral over 4 wires. The other is the typical residential distribution which takes one of the three 7200V (to neutral) phases and a transformer with a single center tapped 240V secondary and delivers this single phase 120V-Earth-120V to the house over 3 wires. There are never center tapped secondaries on a 3 phase system and there is still only one phase with the 120/240V arrangement. It's one or the other, 3 phase or single phase, there is no technological reason they couldn't supply 2 phase power but it isn't done.

[Berni]

The USA electrified very early relative to much of the world, so we were building upon the oldest and most primitive system.

I love these little myths Americans tell themselves about doing things first. 

The first general power station in the world is generally accepted to be in Godalming, Surrey, England. It was commissioned in 1881, and by 1882 8-10 households were connected up. The Holborn Viaduct electric light company started up the same year, and rapidly proceeded to where it had 1000 light bulbs on its supply.

However, I'm sorry to report that the French beat us to as to the first public use of electricity, in lighting up L'Avenue de l'Opera ten years earlier in 1878. The Germans (Siemens) were into the game pretty early too.

Edison's Pearl Street station in New York went into operation the same year as the Holborn Viaduct one in London (also an Edison owned plant), so America was electrifying at the same time as the rest of the world (those bits likely to electrify back in those days), not very early relative to the rest.

In 1887 an 800 kVA power plant was built in Deptford, East London, completed in 1891, it supplied central London over a 10 kV line, believed to be the first use of a high voltage transmission line.

Small, single household private supplies existed before this of course, I'm just talking about public utilities. In the case of private and early public supplies there was little standardisation, which is the point at which systems tend to build inertia.

So there's no special history that forced the US to live with existing standards because they started earlier than anyone else. Everybody was building on "early and primitive" systems at the same time.

Well, I don't know then, I wasn't around back in those days but I'm sure there are historical reasons for it. Geographically the US is over 40 times the size of the UK, meaning things are far more spread out, there is far more infrastructure required per individual home, especially in the vast rural areas so it is far less cost effective to replace existing infrastructure. Maybe culturally we are also more resistant to change, I don't really know. Suffice to say electrical infrastructure we use today is largely compatible with what was being installed 100 years ago, the same ancient plugs will still fit in a the receptacles in a modern house, 100 year old light bulbs will still screw into modern sockets, the voltages are roughly the same now as they were then, and much of it was backward compatible with the DC systems that came even earlier. The lower voltage offered significant advantages for incandescent lighting which was the primary use of electricity in those days, later the proliferation of larger loads meant that 120V (or 110 or whatever it was at the time) was no longer adequate so the 240V split phase was introduced, maintaining compatibility with existing 120V loads.

Here is a fun fact, a lot of Europe used to be 110V/120V but then everyone ended up going to 220V/240V that by now got standardized to 230V

In fact a firehouse here in Slovenia (Or was it Italy, land might have changed hands in that time) has a old lightbulb that has been continuously running for a ridiculus amount of years (Much like the oldest lightbulb in new york or what was it) and is so old that it initially ran off 110V. When they switched over to 220V they wanted the old bulb to keep going so they added another 110V bulb in series.

So we went down the same 110V path here in Europe but then noticed its not really that good of an idea, so we said fuck it, we are gonna do it properly and switched to 230/400V 3 phase running down whole streets. The efficiency of the new system is so much better that we don't even have polepigs. We simply plonk down one giant transformer at the beginning of the street, run the usual 20kV feed to it then run 230/400V straight down the street and connect houses directly to the pole. A single low voltage run down the street might have 30 to 100 houses connected to it. And one transformer might have 3 or 4 such runs coming off it. The wires running over the poles is not even that thick. We only have 2 kind of mains plugs, normal single phase ones for all appliances(even heavy ones) and standard 3 phase plug that is identical to ones used in industry but people have in homes.

So its not that America was first. They just never bothered to switch to the superior system and stuck to the outdated one... much like what they did with the metric system.

[Monkeh]

There are never center tapped secondaries on a 3 phase system and there is still only one phase with the 120/240V arrangement. It's one or the other, 3 phase or single phase

[james_s]

So we went down the same 110V path here in Europe but then noticed its not really that good of an idea, so we said fuck it, we are gonna do it properly and switched to 230/400V 3 phase running down whole streets. The efficiency of the new system is so much better that we don't even have polepigs. We simply plonk down one giant transformer at the beginning of the street, run the usual 20kV feed to it then run 230/400V straight down the street and connect houses directly to the pole. A single low voltage run down the street might have 30 to 100 houses connected to it. And one transformer might have 3 or 4 such runs coming off it. The wires running over the poles is not even that thick. We only have 2 kind of mains plugs, normal single phase ones for all appliances(even heavy ones) and standard 3 phase plug that is identical to ones used in industry but people have in homes.

So its not that America was first. They just never bothered to switch to the superior system and stuck to the outdated one... much like what they did with the metric system.

But as has been laid out already, we have 240V here too and have for many years. What makes single phase outdated and what true advantage does 3 phase offer for residences? Different does not mean inferior, and we've had 3 phase power in the US for a very long time, it has just never been commonly used in houses because it isn't necessary. Houses have few large induction motors, and simple, reliable 3 phase motors are the primary advantage of 3 phase. If I could upgrade my house to 3 phase service for the ridiculously low price of $100 I wouldn't bother. Why would I? What advantage would it bring over this "obsolete" system that I'm using? How do you sell it to a non-technical person who knows nothing about electricity?