Implementation Of An Automatic Induction Motor Starter With Delay Using Microcontroller

Abstract It is well understood that induction motors draw higher currents during their starting operations than is the case under full load running conditions. Since the early days of induction motor availability starting methods other than Direct-on-Line have been used and in some cases mandated by Utilities to reduce the effect of these high starting currents on the electrical distribution network. What is generally not recognized is the existence of short duration inrush currents which greatly exceed these starting currents. Furthermore the introduction of complex starting methods to reduce starting currents is often compromised by other unanticipated inrush currents introduced by the starting system itself unless special precautions are taken. This paper implements a device that protects three phase induction motor from inrush currents on the distribution system as well as on the motor protection components using PIC16F84A Microcontroller.