materials on design and
construction of 3 phase automatic
phase selector
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design and construction of 3 phase automatic phase selector

Automatic Phase Selector
Introduction:
Industries require three phases power to run their machinery. Some of them require continuous \ uninterrupted power to maintain their data. We introduce auto phase selector unit for those equipment whose supply is single phase. The single phase supply is selected automatically from three phases supply.
The objective of the APS is to ensure that there is continued commercial power supplied to the site at all times so as to ensure that the Base Transceiver Station (BTS) runs on commercial power until all available phases are either out of electrical tolerance or completely off. This is a micro controller based unit and is used with three phase electrical supply. Whenever the supply of one or two phases of a three phase electrical line goes off, the APS system automatically distributes the electrical supply from the active phase to the failed phases. This ensures continuous power supply through all the three phases even if one phase is active.
The user can operate this system in Auto and Manual Mode. In auto mode the phase is automatically selected by the controller so there will be continuous uninterrupted supply to the unit.
In manual mode the user will select which phase he wants.
A Microcontroller based system will continuously monitor the incoming phase and accordingly display the details on an alphanumeric LCD also it will display the output phase.
Technical Specification
It monitors all three phases and pass one of them.
It displays all available phases on LCD
One LCD and Keypad with three keys are provided for input from user.
If a phase ® is disconnected. New phase (S/T) will select at once and remain connected.

Auto Phase Selector Switches
The Universal Automatic Electronic Phase Switch (single-phase automatic throw-over breaker) is designed to supply an industrial/ appliance single phase 220V/50Hz load from three phase four wire mains 3x380 N in order to maintain uninterrupted power supply of essential single-phase loads and protect them against unallowable voltage variations in the mains. For this purpose, a single-phase load is switched into a three phase circuit. Depending on voltage presence and voltage quality on phases the PEF-301 will automatically select the optimum phase and promptly switch the single phase load supply to this phase. A phase prioritization is foreseen, i.e. the device restores the supply circuit to the user-selected priority phase after switching to reserve phases and regenerating the voltage on the priority phase.