Thermal and Magnetic Yield Improvement in New Range of Moulded Case Circuit Breaker of 40-160 A with VTVM

Abstract

A molded case circuit breaker, abbreviated MCCB, is a type of electrical protection device that is commonly used when load currents exceed the capabilities of connected system. MCCB gives the protection in case of overload, overcurrent and under voltage fault condition. MCCBs are available from 16A to 2500A ratings in market and are selected based on load application. MCCB can be re-used after clearing fault unlike convention fuse protection. Thermal magnetic release is an important part of MCCB which is responsible for protection against overload and overcurrent fault. The scope of this project will be specific to Thermal magnetic release of current rating 40-160A. In conventional system Thermal magnetic release (TMR) has fixed overload and fixed overcurrent system, but this project will cover TMR with Variable overcurrent (Magnetic) and Variable Overload (Thermal) setting. It is important that each single product should pass all the criteria at maximum thermal and magnetic settings as well as at minimum thermal and magnetic settings. This particular frame of MCCB is generally high demand because of inclusion of low ratings that is 40A-160A. Hence it becomes very important that whatever MCCB are getting produced on production line should have very good yield when tested for thermal and magnetic setting because yield loss for high quantity frame will cost profit margin. In this project different design tools like simulation, calculation, DMAIC will be used to improve yield on production line as well as establish performance at variable setting for thermal and magnetic.