Single phase power has a sine wave voltage that crosses zero before reversing its polarity. In the region near the zero-crossing there is not much power. At zero there is none at all. So single phase loads often need some trickery to deliver output in this area. Often it is just the inertia of the motor or appliance.
Three phase power is always delivering power on one of its phases, and is thus preferred for machines, motors and appliances that use lots of power.
If the application is large power, or small power with weight restrictions (like automobiles!) Three Phase is preferred. DC (Direct Current) is the next step up for smooth high-power devices but requires rectification, regulation and smoothing to be useful.
Another problem with DC is that, for efficient long distance transmission, it cannot be simply converted to much higher voltages than the voltage at which it was generated at the power station. Similarly DC cannot be transformed down to safer, much lower mains voltages for use by consumers.
AC (Alternating Current) is used for high power generation and distribution because it can easily be transformed, using Transformers, to achieve very efficient power transmission over very long distances and can then be transformed down to low voltages for distribution to consumers.
Two phase, and higher multi-phases are also used but very rarely.
Another Answer
Because, for a given load, less volume of copper is required to supply that load, making a three-phase system roughly 75% the cost of a corresponding single-phase system.
To use a single/one phase motor instead of a three phase motor is possible if you have a three phase power supply as you will only need to tap one of the three phases together with neutral and an earthwire, however to use a three phase motor instead of a single phase will require the provision of three phase power supply.
Three phase electricity is used instead of single phase for industrial situations. Industries use three phase electricity instead of single phase to operate electric motors driving heavy machinery. Three phase electrical motors produce more power from the same amount of electricity and maintain steadier speed. Small portable motors such as drills and mixers use single phase. Motors used around the house are single phase. Motors used to run large industrial machines use three phase.
In Europe they have both single phase and three phase.
To convert single-phase power to three-phase power, you can use the formula: P = √3 x V x I x cos(θ), where P is the power in watts, V is the voltage, I is the current, and cos(θ) is the power factor. This formula assumes balanced loads.
347V can be obtained from a three-phase power system, where the phase-to-phase voltage is 347V. This typically involves connecting three alternating current power lines that are 120 degrees out of phase with each other to create a three-phase circuit, which results in a higher voltage output than a single-phase system.
With no three phase power supply you can't use a three phase motor of any kind at all!
To use a single/one phase motor instead of a three phase motor is possible if you have a three phase power supply as you will only need to tap one of the three phases together with neutral and an earthwire, however to use a three phase motor instead of a single phase will require the provision of three phase power supply.
Three phase electricity is used instead of single phase for industrial situations. Industries use three phase electricity instead of single phase to operate electric motors driving heavy machinery. Three phase electrical motors produce more power from the same amount of electricity and maintain steadier speed. Small portable motors such as drills and mixers use single phase. Motors used around the house are single phase. Motors used to run large industrial machines use three phase.
To measure the power of a three-phase load, you need to use one less wattmeter than there are conductors supplying that load.
You need three phase power to get three phase power. If you only have one phase, you will need some kind of inverter or motor-generator set. Generally, however, the demands of a three phase motor will exceed the capability and efficiency of these "tricky" solutions. It is best to simply contact your local power company and have them provide the proper three phase power to your facility.
You will need to determine the power per phase, and add them up to give the total power of the three-phase load. To do this, you will need to multiply the phase-voltage by the phase current by the power factor -for each phase.
Three phase power is a method of electric power transmission using three wires. Three phase power systems may have a neutral wire that allows the system to use a higher voltage while still allowing lower voltage single phase appliances. In high voltage distributions, it is not common to have a neutral wire, as the loads can simply be connected between phases.
You don't. A three phase motor will not start unless it is connected to a three phase supply.
Electric power is measured in watts. It does not matter if it is single phase or three phase. All things being equal, for the same load, the power measured in a single phase circuit or a three phase circuit, will be the same.
A rotary phase converter is commonly used to convert a single phase electrical power source to three phases. This allows you to use three phases instead of one.
Three phase power is always delivering power on one of the phase continuously. This is very useful to manufacturing industries to operate the machines, which require high power utilization.
No. A three-phase ballast requires three-phase power