The increase rate of epileptic power supply especially in tropical African countries where Nigeria forms a part has become a major concern. The power supply instability in developing countries creates a need to device means for alternative power sources. The automation of electrical power generation or alternative sources of power to back up the utility supply could lead to power stability. This automation becomes necessary as the rate of power outage becomes predominantly high. The residence, commercial and industries dependent on generators and public power change-over between these two power supplying sources are manual, human error during change-over connections may occur; leading to machine damage, electric shock/electrocution as well as increased down time consequently introducing massive losses (Mazur and Rocks, 2010). However, when automation takes place between the mains supply and generator it will automatically switch from mains to the generator when there is power failure by starting generator and cut off the generator switching to the mains when there is public power. This help to reduce down time thereby maintaining constant power supply.

1.2 Statement of the Problem

Nowadays securing constant power supply is becoming more important. In Nigeria, power supply for domestic use, commercial and industries is highly unstable. The applications of alternative sources are associated with challenge of switching smoothly and timely between the mains supply and the alternative sources whenever there is power failure on the mains source. The use of an automatic changeover switch with generator cut off and starter eliminate the stress encountered when switching from mains supply to generator Vis visa and reduce time loss for increase productivity.

1.3 Aim and Objectives

This project focuses on the design and construction of an automatic change-over switch with generator cut off and starter.

Hence, the specific objectives are as follow;

1. To provide a system that automatically switches on the generator and switch over the load to the generator whenever there is mains power failure.

2. To provide a device that automatically switches over to mains supply once restored and simultaneously switches off the generator.

1.4 Scope of the Study

The scope of this project is centered the on the design and construction of a change-over switch with cut off and starter of a generator with a capacity of 3.5 KVA.

The project is designed for power supply applications. It involves automatic changeover between the main power supply and an auxiliary power supply, such as a generator. The project implements an automatic switching or starting of the power generator whenever the main power fails.

1.5 Limitation of the Study

The automatic changeover switch with generator cut off and starter does not function with a faulty generating set.

It does not function with generators that have a manual starter which is a sine quo non to the function of the automatic change-over.

1.6 Significance of the Study

The significance of this work cannot be overemphasized. Therefore, benefits that are associated to the change-over switch are;

1. It minimizes damages to lives and equipment since it has its own monitoring system and its switching requires no human contact with the switch, thus eliminating human error.

2. It reduces change-over time to a minimum, due to its fast response to power restoration.

3. It maintains high quality of service through its fast and prompt response.

4. Moreover, the unit is portable, easy, convenient and safe to install.