ABSTRACT

The basic aim of the design and construction of this three phase automatic phase selector is to demonstrate how contactors can be used to switch in between three lines or phases e.g “RED, YELLOW AND THE BLUE PHASE” without interfering with the contacts.
This type of phase selector is able to switch between phases with the aid of inter-locking one phase to the other either one phase circuit is dependant on the other phase circuit which means that two phase circuit which that two phases cannot come on at the same time.
This research work is divided into six chapters, chapter one emphasizes on the introduction of the topic, the second chapter centers on the review p=of related literature as it regard to the design and construction of this Automatic three phase selector. 

CHAPTER ONE

1.1 INTRODUCTION
In Nigeria today the problems of power outage across phases is so rampant thus leading to some sensitive equipment and appliances being redundant, this could sometimes be the cause of one phase going out with respect to the other.
It may surprise one to note that in an attempt to solve this problems, so many unskilled electricity consumers has in recent past resorted to some crude means of swapping between phases to obtain power. So many souls have been lost in this act. This is an undesirable condition to consumers and the need now arises to design a device that can automatically select among the phases and make power supply available at the consumers terminal.
However, this can only be possible if one have a three phase met or and there is supply from any of the service line or the entire line, this project known as a three phase automatic phase selector has been constructed with a view of solving the problems stated above. The design and construction was based on the principle of Electromagneto-Dynamism and alignment as demonstrated in the contactor arrangement.
Among other components are the timers miniature-circuit breakers the contactors and indicator bulbs, the ease with which the device is operated is well elaborated to ensure simplicity effort were made to present a stop by step operation of the project. As much as there is no project without limitation and applications, we have as well dedicated a section of this paper to look into it.
In order to ease the effort of technicians in restoring the devices should there be any malfunction associated.
Faults and how they are cleared is presented, however, there are no user serviceable parts in the device therefore all maintenance should be referred to a qualified electrical personnel.