Design and Construction of Automatic Three Phase Selector System

Design and Construction of Automatic Three Phase Selector System


Design and Construction of Automatic Three Phase Selector System


Abstract of Design and Construction of Automatic Three Phase Selector System

Automatic 3 phase selector switch is a replacement of 3 phase manual change over cut fuse from one cut out to another. Automation 3 phase selector switch has an input of 3 phases from PHCN but has one output that supply current to the load. The device monitors the voltage supply of each phase (Red, yellow and blue) when theirs power failure in a particular phase it will automatically change over to another where their is voltage supply and also monitors the amount of voltage in each phase and select the voltage that is more higher than others and give it out as a single phase power supply. Automatic 3 phase selector switch help to minimize the stress of operating a change over switch from one phase to another manually, and also the risk of been electrocuted.



Chapter One of Design and Construction of Automatic Three Phase Selector System



Initially, 3-phase voltage selector system invented manually with operating process of time wasted and inconvenience. The interest of automatic 3-phase voltage selector system is on the fact that technology advancement has made it possible to minimize cost, hard labor and time wasted, and also improves the reliability of our electrical and electronics system. Therefore with the help of electromechanical switching system through the principle of solenoid, a system has been designed such that electromechanical device like a relay and contactor is arranged to automatically change from one phase to other without human intervention. This design is of high efficiency and very accurate in its performance, this is because switching is done by automation without time delay. The 3-phase automatic voltage selector system uses reliable electrical/electronics components such as relay transformers, contactor, diode capacitor, resistor and other switching component.

The operation of this device is that when there is a failure in any of the each line thereby leading to a no output voltage, it select automatically to other phase without time delay. This project is applicable in homes, factories, corporate offices and commercial business center. This system also transfers maximum power to the load.


The objective and aim of this research is as follows:

I.                      To select automatically a voltage that is present in power line.

II.                      To avoid stress and inconvenience in selecting of phase voltage.

III.                      To build a system that can be able to choose any voltage that appear to be of high potential among other voltage.


This research work is important in various ways

(a)        To Individual:      It helps to avoid the stress of working and selection of phases if there is a failure in any of the available phase.

(b)  To Student (i) It helps to lay a foundation of research work about the automatic 3-phase voltage selector system.

ii      It also helps the student to research about a  related topic.

(c) To Society: It also shows technological advancement in power     system voltage control.


This research work select automatically AC phase voltage supply from PHCN. This does not involve change over switch from power main to generator switch. It also helps to select the maximum voltage required. This research is purposely design for AC voltage only.


The hindrance encountered on this research work are:

·        Financial Crises

·        High cost of material/component.

·        Research group misunderstanding

·        Physical stress

·        Miscalculation

The hindrances encountered on this research work is

Financial crises

High cost of material/component

Research groups misunderstanding

Physics stress


Financial Crises:      Financial crises will also contribute to the problem encountered on this research work, financially, the money won’t be available to buy all the component and material needed to construct this project due to human want.

High cost of material/component: Based on high cost of materials/component.

It can also be a reason for a student not to embark on this project rather, it will also look for the one it material is low.

Research group misunderstanding: In any group of people or organization there must be a dispute between them. This   can be another issue that can cause a hindrance to this research work.

Physical stress: Not everyone has the opportunity or the physical stress to embarked on this project based on time, opportunity and physical fitness.

Miscalculation: Mathematically, miscalculation can cause a problem  in a group base on financial issue.


This research is well organized in a systematic step-by process for easy reference and search of information. This report contains six chapters and each chapter is made up of a maximum of five sections and all the diagram, calculation and sketches are referred to as figures and they are tagged according to the section they are under:

Chapter one (1) contains: Background of the study, Objective/aim of the study, Significant of the study,  The scope of the study, Limitation of the study, Organization of the study. While Chapter two (2)contains:  Literature review, Theoretical frame work, any other available information related to the topic of the project, pictorial, charts, data etc also Chapter three (3)contains: Design methodology (design analysis, investigation and data concept), Specification, Block diagram, Circuit design, Circuit diagram while Chapter four (4) contains: Construction, testing and packaging, Actual process, materials and method of construction are explained in detail,Testing instrument, equipments and testing techniques, Assembly and packaging (prototype) also Chapter Five (5) contains:

Beme, (Bill of Engineering measurement and Evaluation), This should be in tabular form, price lists, quantities, rate per and total cost and Chapter six (6) conatins: Summary, Conclusion and recommendation and Appendices.