Description
INTRODUCTION
Change over switch is a device used to switch off a power supply and subsequently switch on another power source. Basically it is aimed at switching on a more convenient power supply to the load. Since it switches on power to the load precaution has to be taken while choosing the type of change over switch. Also size, arcing control are put into consideration in the choice.
A good switch should be the one whose contact is made in such a way as to limit the arc formation by having no contact-bounce and by having contacts made of good conductive, corrosion resistance and wear resistance materials.
A good change over switch must have adequate insulation and must be so constructed and located as not to constitute a potential hazard.
A good change over switch should also have tight contacts so as to limit or eliminate the possibility of partial contacts at the contact point. The partial contact lead to over heating of the components and may lead to fire out break.
TABLE OF CONTENTS
Title page
Approval page
Certification
Dedication
Acknowledgement
Table of content
CHAPTER ONE
1.0 INTRODUCTION
1.1 Aims and Objective
1.2 Scope and limitation
CHAPTER TWO
2.0 LITERATURE REVIEW
2.1 System Operation of the Automatic Power
2.2 The Stand by Power Unit
2.3 Requirement for a Generator to be used on Change Over Switch
CHAPTER THREE
3.0 COMPONENT AND DESCRIPTION
3.1 Contactors
3.2 Contactors Mode of Operation
3.3 Circuit Breaker
CHAPTER FOUR
4.0 CIRCUIT DIAGRAM AND OPERATION
4.1 The NEPA Supply Unit
4.2 The Phase Selector Unit
4.3 The Generator Unit
4.4 Circuit Operation
4.5 Sequence of Operation
4.6 Testing and Result
4.7 Packaging
CHAPTER FIVE
5.0 OBSERVATION SUMMARY AND CONCLUSION
5.1 Observation
5.2 Summary
5.3 Suggestion
5.4 Conclusion
References