DESIGN AND CONSTRUCTION OF THREE PHASE (3-) AUTOMATIC CHANGE-OVER SWITCH

ABSTRACT Design and construction of three phase (3 ) automatic change-over switch, using microprocessor based seven segment display is a means of reducing stress in changing power manually. Most industrial commercial and domestic process are dependent on electrical power. In the event of power interruptions, the change-over from power supply by a public utility to a generator is usually performed manually, often resulting wasting of time and interruption of on-going process. Moreover, machine damage some times occurs because of human errors. This project present the design and construction of the three phase automatic change-over switch that switches electrical power supply from public supply to Generator in the event of an insufficient voltage. The systems uses an electronic control circuit involving integrated circuit, transistor and electromechanical devices. The microprocessor display in this project is to show when there is power either from PHCN or Generator and also when there is power or not in each of the phase (R,Y,B). It can be denoted by 1 when there is light (ie there is power) and Blank when there is no light (ie there is no power). Key word, Relay, public supply voltage, Generator, switching, electronic control circuit, transistor and microprocessor. In chapter one it talk about introduction, chapter two literature review, chapter three the principle of operation. Construction Analysis in chapter four and chapter five the conclusion and Recommendation.