Arc Flash
Arc flash is the intense light and heat released during an electric arcing fault when current flows through ionized air between phases or phase-to-ground, causing an explosive energy release that can vaporize metal conductors and reach temperatures up to 35,000°F (19,400°C).
In shop floor maintenance, arc flash hazards are managed through Arc Flash Studies per IEEE Std 1584 to calculate incident energy (cal/cm²) and determine the Arc Flash Boundary for equipment labeling. In CMMS systems like ServiceGrid, assets are tagged with Arc Flash Boundaries and required PPE classes, and mandatory NFPA 70B-2026 maintenance tasks (e.g., cleaning, tightening, testing) are scheduled to prevent insulation failures. Safety protocols establish Limited, Restricted, and Arc Flash Approach Boundaries in work orders to enforce safe working distances and PPE usage during live electrical work.
How is incident energy calculated?
Using IEEE Std 1584-2018, factors include voltage, fault current, working distance, and upstream device clearing time; energy increases with higher current and longer clearing times.
What distinguishes arc flash from arc blast?
Arc flash is the radiant heat and light; arc blast is the supersonic pressure wave and concussive force generated when vaporized metal expands the air.
What is the threshold for a second-degree burn?
1.2 cal/cm² (5 J/cm²) incident energy on exposed skin defines the Arc Flash Boundary.