Arc Flash\Blast, Safe by Design a Safety Integrity Level approach (SIL)

This paper illustrates the application of a Safe by Design approach developed by the process industries to determine the effectiveness of arc flash\blast risk control techniques using functional safety techniques used to determine the integrity of emergency shutdown systems. It is proposed that with the adoption of risk analysis practices detailed in NFPA70E-2015 Informative Annex F Risk Assessment Procedure, the risk assessment process lends itself to calibration with the process and machinery functional safety standards, (ISA84.01, IEC 61508, IEC 61511, IEC 62061), for electrical/electronic/programmable electronic safety systems. Using this approach, it is possible to determine the Safety Integrity Level (SIL) requirements of the Arc Flash\Blast risk control system and design it in the same manner as a process emergency shutdown system, and/or a machinery safety system. Using this approach in the design phase enables you to build a defendable and economical arc flash mitigation system and also demonstrate duty of care has been exercised. Worked examples are utilized to demonstrate the application and use of the technique.