Protection, control, reliability and diagnostic improvements via single-processor control of circuit breakers in low voltage switchgear

Protection of low-voltage circuits has been a key area of innovation and continuous improvement since the invention of electricity. In the current state of the art, fuses and circuit breakers protect individual circuits. These devices, in turn, use many different kinds of trip mechanisms, operating in various modes that require sensing the current that travels through the circuits. However these devices, largely, operate separately and independently from each other. Communication networks and external relays are sometimes used to enhance selectivity and provide better protection that the independent over-current devices can provide. In this paper, the authors explore a protection-and-control architecture based on a single processor that provides all the protection and control functions for a line up of low-voltage switchgear. How this method of protection changes the paradigm from individual circuit protection to system protection, while cost-effectively and significantly increasing system reliability and protection is discussed.