DESIGN AND CONSTRUCTION OF AN AUTOMATIC SINGLE PHASE CHANGEOVER SWITCH

DESIGN AND CONSTRUCTION OF AN AUTOMATIC SINGLE PHASE CHANGEOVER SWITCH

ABSTRACT

The primary goal of any electric power supply in the world is to provide continuous power supply to all of its consumers at all times. However, in developing countries, the amount of electricity generated to meet the growing demand for electricity is insufficient, resulting in power instability and outages.

Power insecurity or outages in general do not promote public or private sector development. Investors are hesitant to enter a country with frequent or constant power outages. These restrain the growth of industries. Furthermore, there are processes that cannot be interrupted due to their importance, such as surgery operations in hospitals, money transfers between banks, and many others. Power insecurity and outages in developing countries (such as Nigeria) create a problem.

Alternative power sources are required to supplement the mains supply.

Automatic changeover switches have a wide range of applications where the reliability of electrical supply from utilities is low, and they are used in lighting/motor circuits where supply continuity is required, for switching to an alternative source from the main supply and vice versa.

This project involves the creation of an automatic changeover switch. This means that if the power goes out, the automatic changeover switch will switch to an alternate power supply (generator) and then back to the main supply when power is restored. The goal of this project is to maintain a constant supply to the main circuit that is being supplied by compensating for the time lag or delay that normally occurs.

the act of manually switching from one source to another.

The power connection circuit and the control connection circuit are part of the design. Contactors, relays, and a timer are the primary components to be used.

CHAPTER ONE

1.0 INTRODUCTION

The demand for continuous power supply and reliability has grown rapidly over the years, particularly in areas where uninterrupted power supply is critical. Power is essential in modern systems. Their complexity has grown as continuous information and communication are required to control automated processes in industries, commercial complexes, hospitals, hotels, and even modern homes. As a result, the demand for an independent standby power system has skyrocketed. Standby power distribution, control, monitoring, and protection must all be integrated. Standby generator systems, for example, must provide:

UPS systems are used to power sensitive loads. Battery banks bridge the period of non-availability of power before the standby supply takes over. Computers, hospital equipment, and other common loads

Industrial machines controlled by microprocessors, for example.

Critical loads are typically standby generator systems that power lighting systems, air conditioning, elevators, and other systems in airports, hotels, and commercial complexes.

Standby generator systems are also used for essential loads, which are mostly found in process industries due to their high restarting or downtime. All of the above loads require automatic switching from mains to standby power. (11)

In the event of a power outage, standby power is typically expected to automatically take over. Automatic operation necessitates the use of electrical starting equipment, a battery bank, and a diesel generator. The automatic transfer is mostly accomplished by automatic mains failure systems. The on-load transfer process must be monitored and controlled to ensure a smooth changeover.

within the system’s safety limits. An Automatic Changeover Switch accomplishes this.

Changeover switches are used in lighting/motor circuits where continuity of supply is required, for switching to an alternative source from mains supply and vice versa, and they have a wide range of applications. They are switch disconnectors with independent manual operation that can make, carry, and break currents under normal circuit conditions, which may include operating overload conditions, as well as carrying currents under specified abnormal circuit conditions, such as short circuit for a specified time. (1)

The automatic changeover switch (also known as the automatic transfer switch ATS) is an essential component of the power generation process, allowing for smooth and efficient operation. Electric current is transferred instantly between multiple sources and loads. When the generator is running, the transfer switch prevents any feedback current from reaching the load. It also ensures that the various power sources are synchronized before transferring the load to them. If the mains supply is not present, the transfer switch detects an interruption. Fluctuations and voltage drops below a certain level in the mains supply within a specified time will also cause the automatic transfer switch to transfer the load to the generator. The generator is started by a relay that switches the battery voltage to the generator’s ignition coil. When the generator is producing full power, the transfer switch disconnects in a matter of seconds. The load is disconnected from the mains supply and connected to the generator supply, restoring power to the load. The transfer switch continues to monitor the mains supply and, when it is restored, switches the load back to the mains supply. When the generator is disconnected, it goes through a cool down routine and automatically shuts down.

1.1 PROJECT AIMS AND OBJECTIVES

This project’s goals and objectives are to

1. Design and build an automatic changeover switch that will easily switch load from the mains power supply (PHCN supply) to a backup power supply (generator).