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# Three phase to single phase (inverter)

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### Three phase to single phase (inverter)

Could some explain to me how a three phase input into a UPS gets converted into a single phase output.
Thanks
Regards
Peter

## Basically

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Hi,
With UPSs whether single or three phase, the mains is converted to low voltage DC and used to charge a battery. From this battery an inverter converts the DC to mains voltage AC.
If the mains fail, then the battery continues to carry the load for a short time, but usually enough to shut down computers.

## your question 3 phase to single

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Hi Their did you know your motor car uses a alternator which generates 3 phase ac and then is converted to single phase through a 3 phase rectifier to give dc output,this can then be used make single phase ac at the voltage you require say 240ac to your ups backup.

Regards Kenny

## A little info on Three phase to single phase..

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Three-phase electric power is a common method of electric power transmission.[1] It is a type of polyphase system mainly used to power motors and many other devices. A three-phase system uses less conductor material to transmit electric power than equivalent single-phase, two-phase, or direct-current systems at the same voltage.

In a three-phase system, three circuit conductors carry three alternating currents (of the same frequency) which reach their instantaneous peak values at different times. Taking one conductor as the reference, the other two currents are delayed in time by one-third and two-thirds of one cycle of the electrical current. This delay between "phases" has the effect of giving constant power transfer over each cycle of the current, and also makes it possible to produce a rotating magnetic field in an electric motor.

Three phase systems may or may not have a neutral wire. A neutral wire allows the three phase system to use a higher voltage while still supporting lower voltage single phase appliances. In high voltage distribution situations it is common not to have a neutral wire as the loads can simply be connected between phases (phase-phase connection).

Three phase has properties that make it very desirable in electric power systems. First, the phase currents tend to cancel out one another, summing to zero in the case of a linear balanced load. This makes it possible to eliminate the neutral conductor on some lines; all the phase conductors carry the same current and so can be the same size, for a balanced load. Second, power transfer into a linear balanced load is constant, which helps to reduce generator and motor vibrations. Finally, three-phase systems can produce a magnetic field that rotates in a specified direction, which simplifies the design of electric motors. Three is the lowest phase order to exhibit all of these properties.

Most domestic loads are single phase. In North America and some other countries, three phase power generally does not enter domestic houses at all. Even in areas where it does, it is typically split out at the main distribution board.

The three phases are typically indicated by colours which vary by country.
More here:
http://en.wikipedia.org/wiki/Three-phase_electric_power

Please post back if you have any more problems or questions.