An Overview Of Mcb, Mccb, Elcb, Rccb Circuit Breakers

Description

ABSTRACT

The circuit breaker is an absolutely essential device in the modern world, and one of the most important safety mechanisms in homes. Whenever electrical wiring in a building has too much current flowing through it, circuit breaker cut the power until somebody can fix the problem. Without circuit breakers,  household electricity would be impractical because of the potential for fires and other mayhem resulting from wiring problems and equipment failures.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

CHAPTER ONE

INTRODUCTION

1.1      BACKGROUND OF THE PROJECT

• AIM OF THE PROJECT
• OBJECTIVE OF THE PROJECT
• SCOPE OF THE PROJECT
• ADVANTAGES OF A CIRCUIT BREAKER
• DISADVANTAGES OF A CIRCUIT BREAKER

CHAPTER TWO

LITERATURE REVIEW

• OVERVIEW OF CIRCUIT BREAKER
• ORIGINS OF CIRCUIT BREAKER
• OPERATION OF CIRCUIT BREAKER
• STANDARD CURRENT RATINGS

CHAPTER THREE

METHODOLOGY

• WORKING PRINCIPLE OF CIRCUIT BREAKER
• DIAGRAM OF CIRCUIT BREAKER
• DIFFERENCE BETWEEN MCB AND MCCB, ELCB, RCCB

CHAPTER FOUR

TEST

• TESTING OF CIRCUIT BREAKER
• CIRCUIT BREAKER RATINGS

CHAPTER FIVE

• CONCLUSION
• RECOMMENDATION
• REFERENCES

CHAPTER ONE

1.1                                          INTRODUCTION

Circuit breakers are an essential part of the protection system of every electrical network. They automatically disconnect the circuit in the event of an overload or a short circuit, preventing damage to the network and its equipment. They exist in many different sizes, ranging from miniature circuit breakers that protect a single household appliance to large devices that protect high-voltage circuits in industrial and utility networks.

Circuit breakers must be able to carry a high load without excessive heating. They also must withstand the thermal and mechanical effects caused by the maximum short circuit current that can flow through the circuit. Opening the circuit generates an internal arc between the receding contacts, which the breaker must contain, cool, and extinguish in a controlled manner

1.2                                    AIM OF THE PROJECT

The main aim of this work is to write on different types of circuit breaker such as mcb, mccb, elcb and rccb circuit breakers.

1.3                            OBJECTIVES OF THE PROJECT

At the end of this work, student involved shall be able to understand:

1.     The description of circuit breaker,

2.     The importance of circuit breaker,

3.      The difference between circuit breaker and fuses,

4.      Different rating and application of circuit breakers,

5.     Understand different types of circuit breakers and their applications

1.4                                  SCOPE OF THE PROJECT

A circuit breaker is a switching device that interrupts the abnormal or fault current. It is a mechanical device that disturbs the flow of high magnitude (fault) current and in additions performs the function of a switch. The circuit breaker is mainly designed for closing or opening of an electrical circuit, thus protects the electrical system from damage.

1.5                    ADVANTAGES OF A CIRCUIT BREAKER

The advantages of a circuit breaker are:

1. they are smaller in size than fuses
2. better versions may have electronic trips so they can adjust trip curve to suite circuit design
3. easier for end user to reset (no touching live parts)
4. no waiting to reset (as with fuses – spare must be found)
5. no cost associated with resetting unlike cost of replacement fuses
6. easier when ground fault protection is needed

1.6             DISADVANTAGES OF A CIRCUIT BREAKER

The disadvantages of a circuit breaker are:

1. they are more expensive than fused switches
2. when a circuit breaker trips, you lose all power (with fuses you only lose that phase)
3. harder to coordinate fault selectivity
4. harder and more costly to obtain high short circuit interrupting capacities