Three-Phase Power for Residential Use

It depends entirely upon the energy consumption and the tariff chargeable locally. The best people to contact are the suppliers of the electricity.

As the three phase system consumes less current compare to single phase system so it is beneficial in terms of energy consumed,but the cost of installation is higher.

In India domestic supply voltage is 230V,single phase,50hz.Three phase standard supply available in India is 415V,50Hz.It is used by the commercial and small industrial house.

The ONLY reason to bring 3 phase power into a residence is if you plan on using 3 phase motors in it. All home appliances are built for 1 phase supplies, so there is no point in spending the extra money for a 3 phase service unless you plan on doing some industrial work at home, such as a machining tool or large air compressor.

Forget the comment about it being less current, that is totally irrelevant. Nobody is billed on current, we are billed on wattage (kWh) and wattage has only to do with connected load. In other words if you have a 1kW motor on your refrigerator, that will consume 1kW no matter if it is a 1 phase 230V motor or a 3 phase 400V motor. So you will pay exactly the same amount.

I also want to highlight a practical problem here in India. The initial approval with single phase with a particular load will come with an energy meter. But later on when people add on loads like adding air-conditioners indiscriminately they don't see the capacity of the energy meter (or for that matter even the size of the cabling) and this leads to meter (cable) burnt.

beneficial part: a 3 phase connection with a phase change over switch could be advantage during single phase failure which is frequent in India.

kayems

In Holland we have 3 phases where the electricity comes into the house,

we can/could install a 3-phase electrical cooking stove. It is also better for load issues as we can distribute the electrical load over 3 phases

I recently discussed this topic in another forum but can't quite find it so I reproduce it below.

According to Andy Germany, in Germany they bring 3-phase to every apartment and house.

100amp single phase service is normal to a UK house, as it is here in NZ, dropping to 63-80 amps for small apartments. Single phase showers are available up to 12kW or so; a 10kW or 45amp shower is very satisfactory and certainly enough to turn my wife into a lobster!

If 3-phase is supplied to every house, I totally disagree that this is either necessary or appropriate. This is a very small increase in efficiency for the minority, but simply increases the cost, complexity and to a certain extent the risk (higher voltage) for less benefit to the vast majority. Balancing 3-phase only becomes necessary at sub-station and street-feeder level.

A 3-phase supply to a house will never be balanced. Balancing requires an "aggregate of loads" and there are too few in an average house. So for example as soon as you boil a kettle there are no corresponding single-phase devices used elsewhere in the home (and there must be 2) to compensate. You will get an aggregate of loads across a street or apartment block, as everyone tends to use the same devices at the same time, but only if these devices are on different phases. If you can control which house gets which phase, this is possible and the sub-station is happy, but only if the supply authority delivers 1-phase to each dwelling. The authority accepts the (irrelevant) fact that a house is "imbalanced", on the proviso the entire street is in balance, and apportions phases to each dwelling in rotation.

However if you supply each house with 3-phase, the Authority loses this control. We ignore 3-phase loads as these are balanced already. However there is no way to ensure that a kitchen is on phase A in one house, but phase B the next and so on. It is perfectly possible that every kitchen in a street is on Phase A for example. So when the advert arrives in the middle of Das Boot and everyone runs to the kettle, the whole street is imbalanced and no-one finds out if Jürgen Prochnow lives :-)

So I support the system that everyone gets 1-phase and the associated lower cost, simplicity and greater safety this option provides. 3-phase is available then to those who need it and are willing to pay. Above 100amps, 3-phase is provided in the UK anyway.

Interested to hear yours and other comments on this subject. Perhaps this should be another forum topic.

There are standards for that when they built a new house or area and an engineer from the electricity company will check if the distribution of the VA is even.

If you are, for example, a "heavily" into DIY type of person like myself, or if you need to cut wood for a fire or for woodworking, having 3 phase is a boon. Powerful tools are available to be used.....

For people who have no interest in this type of area, the benefits are minimal.....except that if a fuse does go, generally speaking, some lighting still works and you could run extender cables.......till the guy comes along to replace the company fuse....

Its "Normal business" here, nobody even thinks of a single phase for a house anymore....

Three phase is also brought into most homes in Norway. I have seen it in a new installation in a small sea-side home as of 2009.

As for balancing appliances between the phases, sure, you won't have a perfect balance. But how is US 120V/240V split-phase any better? It also suffers from balancing problems between the two split phases.

Consumption will not differ either it is 1ph or 3ph.

What is your connected load?

for single ph connection sanction load is limited by the supply company. If your load requirement is more than that then you have to take three phase connection.

I live in Flanders (Belgium) and have a 3 phase connection at home.

I rewound the electric motor of my lawn mower from one phase to three phase.

• now it is more powerfull,
• it's much stronger at start (I don't have to clean the grass outlet pipe, when I empty the grass basket)
• it turns a little faster
• and it vibrates less.

only benefits ….

A three phase electric lawn mower? Dang, that sounds cool!

Three phase power was not brought to residential areas in the US because of the original costs incurred for distribution. Keep in mind we are talking about the standard being set in the 1940's. Many small town areas didn't even have three phase distribution in the commercial areas. Three phase Delta systems were used since you only had to mount two xfmr's instead of three.

Once large AC's were introduced in the 1950's they were only manufactured as 3 phase. So the original units put in homes were 3 phase. The utility company came up with a simulated 3 phase system called a Delta high leg which they installed only for the AC unit.

When a utility sets up distribution to a residential area it comes to the are as a 3 phase system and it is then broken down into 3 single phase systems. The only reason you would want a 3 phase system is because it is more efficient. You could also step it up from a 3 phase 208V Wye, to a 3 phase 480V Wye and it would be even more efficient.

About the only advantage I see is if you have access to used industrial equipment (such as welding machines/lathes/mills) and want a cheap machine shop in your garage, three phase is essential. Here in the USA, in the rural areas of western Pa, getting three phase to a residential unit requires proof that you are going to run a business on the property. I have a friend who purchased a used welding machine and needed three phase to run it - he had to fool the power company into believing he was starting his own welding shop on the property to get three phase power.

Insofar as delivery of true power, 3 phase can deliver the same amount of power using 50% less copper than single phase.This creates less losses due to self heating of the conductors,etc.Multi-phase systems can be of any voltage design.I have seen some machinery running on 120v 3 phase, and 48 volt 3 phase( a large open end spinning frame).The present infrastructure in the USA is not designed to distribute 3 phase to residental customers.

Large computer rooms use 3 phase for power to balance loads and prevent harmonics that would be present on a single-phase system with lots of switch-mode power supplies.

----SSB-----------

so far as bill is concerned it all depends on how much energy u use which is same for both single phase and three phase meters. but there can be other advantages like some times electricity comes in one or two phases. having access to all phase u can use change over swich to swich to any phase. secondly in small cities there is under voltage problem specially in summer. that time also u can select particular phase having maxm voltage. three phase supply is good for homes with large consumption and generally alloted to domestic consumers with large loads only.