ABSTRACT

This project describes the methodical approach to the design and construction of control system for direct-on-line starting of induction machine. The procedures developed covers the construction of D.O.L stated for lower horse power motors. The prototype of this direct-on-Line starting of induction machine has been implemented following the methodical approach outlined in this project and its operational test and result are quite satisfactory. Adequate care has been taken in the design and construction of this project to ensure reliability. Therefore, the project is aimed at controlling the operation of single phase and three phase motors in industrial drive, companies, homes, laboratories and hospitals thereby reducing economic waste.

CHAPTER ONE

1.0     INTRODUCTION

Design and construction of control system for direct-on-line starting of induction machine: This is a control system that can control a single phase (1Ø) motors and three phase (3Ø) by making use of the components such as contactors, over current relay, start button, stop button etc. the contactors provides switching devices while over current relay is positioned to render protection to the machines in case of over current surge, the start and stop buttons called push buttons are used to start and stop the control contactor system. Again, there are pivot or indicator lamps which are controlled by normally open and normally closed of the auxiliary contacts incorporated to indicate when there is voltage supply to the three phase (3Ø) or single phase (1Ø) or both phases. However, the whole control system is controlled by mechanically pressing the push button ON and OFF when the circuit breaker has been switched ON.

The energy needed for the operation of the control system is three phase and one neutral through the input to produce single and three phase at the output terminal.

Finally the mode of operation is shown on the circuit diagram of the control system.

Organizational report: In chapter, 1 discussed about the background, aim, scope and limitation of the project.

In chapter two, literature review of the project is discussed and elaborated.

In chapter three, the design methodology (design Analysis, investigation and data) is discussed.

In chapter four, construction, testing and packaging is described.

In chapter five, Bill of Engineering measurement and evaluation (BEME) are stated.

In chapter six, this is where the summary, conclusion and recommendation, reference and Appendices are stated.

1.1     AIMS/OBJECTIVE OF THE STUDY

The aims/object of embarking on the project are:

1)          To produce a system that will protect electric motor.

2)          To design a control system that will start induction machines without causing damage to the equipment.