Arcing fault hazards and safety suggestions for design and maintenance

Significant progress has been made in understanding the hazards of arcing faults to maintenance personnel working on electrical equipment. The National Electrical Code (NEC) requires that equipment be installed the way it is listed and labeled. However, the NEC and product standards do not address the hazards associated when the equipment doors are open and a maintenance worker accidentally creates an arcing fault. Numerous workers are injured and killed each year while working on energized equipment. To address this, the IEEE Petroleum and Chemical Industry Committee formed an ad-hoc working group within their safety committee with the intent to raise awareness of electrical personnel to the hazards associated with arcing faults. Tests were run at a high-power test lab and analytical information was gathered to quantify the hazards associated with arcing faults. Arcing faults have many variables and the predictability is not certain. However, the work by many on this subject provides some good engineering analytical tools. These efforts have also resulted in industry awareness, safety training program materials, and guidelines for electrical systems design. This article highlights some of these findings and also presents some design considerations that will help reduce the hazards of arcing faults.