Integrating advanced relays on medium voltage switchgear with safety control systems

This paper describes how a switchgear modernization project in a major petrochemical and refining process opened the door to new methods of integration between substation protection and process safety automation. It explores how a risk mitigation project's need for a Safety Instrumented Function (SIF) to detect a refinery wide power outage used the technology the modernization project provided without adding new equipment. Traditional practices used in the refining industry keep electrical substation protection and process safety automation separate, but microprocessor technology allows for the integration of these two fields of practice. This method of integrating process safety into electrical equipment introduces a need for electrical manufacturers to learn and follow the regulations used in process safety automation in order for their equipment to be used in Safety Instrumented Systems (SIS). The combination of these two fields of practice and their associated projects allowed fewer components to be installed and therefore less cost while maintaining reliability and maintainability. The paper will explore the design efforts to combine the projects, the challenges to modify the equipment and the process used to commission the equipment and demonstrate that the system worked as expected.