ABSTRACT
The main aim of any electric power supply in the world is to provide uninterrupted power supply at all times to all its consumers. Although in developing countries, the electric power generated to meet the demands of the growing consumers of electricity is insufficient hence instability and outage. Power instability or outage in general does not promote development in the public and private sector. The inventors do not feel secure to come into a country with constant or frequent power failure. These limit the development of industries. In addition, there are processes that cannot be interrupted because of their importance. For instance, surgery operation in hospitals, transfer of money between bank and lots more. Power instability and outage in developing countries (Nigeria) creates a need for alternative source of power to backup the main supply. Automatic changeover switches find a wide application scope wherever the reliability of electric supply from the utilities is low and it is used in lighting motor circuits wherever continuity of supply is necessary. For switching to an alternative source from main supply and vice versa.
This project is a design of an automatic changeover switch this means that when there is any mains failure, the automatic changeover switch will change to an alternative power supply (GENERATOR) and back to the main supply when it is restored.
The purpose of this project is to maintain constant supply to the main circuit that is being supplied by making up for the time delay that usually accompanies the manual switching from one source to another.
The design comprises of the power connection circuit and control connection circuit. The main components to be used include contactor, relay, timers, rectifier e.t.c.
TABLE OF CONTENTS
Title Page i
Certification ii
Acknowledgements iii
Abstract iv
Table of Contents v
CHAPTER ONE
1.1 Introduction 1
1.2 Aim and Objective of the Project 3
1.3 Scope of the Project 3
CHAPTER TWO
2.1 Literature Review 5
2.2 Manual Change-over Switch 5
2.3 Automatic Change-over Switch 6
2.4 Related Work 10
2.5 Reasons for Automatic Change-over Switch 16
2.6 Problems of Automatic Change-over Switch 17
CHAPTER THREE
3.1 Methodology (Material and Methods) 18
3.2 Circuit Conductor 18
3.3 Circuit Breaker 19
3.4 Reset Timer 20
3.5 Contactor 21
3.6 Operation of Timer Delay 24
3.7 Principle of Operation 25
CHAPTER FOUR
4.0 Construction 29
4.1 List of Component Used 29
4.2 Vero Board 29
4.3 Bread Board 30
4.4 Soldering Iron 33
4.5.1 Testing, Maintenance and Discussion 36
4.5.2 Polarity Test 36
4.5.3 Insulation Resistance Test between the Live and Neutral Conductors 37
4.5.4 Earthling Test 37
4.6 Maintenance of Contactor and Installation 37
CHAPTER FIVE
5.1 Conclusion 39
5.2 Recommendation 39
References 40
Bill of Engineering Measurement and Evaluation (BEME) 41
