Development of Electromechanical Release for Higher Rating current (800A) of MCCB

Abstract

The project includes a new development of electromechanical release for higher rating current of (800A) moulded case circuit breaker (MCCB). This is a replacement of microprocessor release by using both mechanical as well as electrical concept. Electromechanical release provides two types of protection which are overload current protection and the short-circuit protection. The thermal property of bimetal (gets elongated when heating) is used to sense the overload of current and magnetic property (magnetic flux/induction) is used to sense the short circuit.

This project is divided in two parts, the first part deals with the protection against overload of the current. Here by using reverse engineering concept, bimetal for higher rating current is selected and the shape and size of the bimetallic strip is decided as per the movement required for trip plate to trip the MCCB. While second part deals with the development of magnetic construction trip unit protect against short circuit using mathematical calculation and soft tool Pro-Engineer and JMAG.

The proposed concept for electromechanical release has been finalized by analysis on soft tools like JMAG and mathematical modeling. The prototype of new developed release has also been validated on MCCB. After completion of concept validation, the proposed electromechanical release would be consider for higher rating current MCCB.