ArcFlash

Arc flash is a rapid release of energy caused by an arcing fault in energized electrical equipment. The arc can jump between conductors or between a conductor and ground, producing intense heat, bright light, a pressure wave, and flying debris. Arc flashes can occur in switchgear, transformers, motor control centers, and other energized systems, especially during maintenance or fault conditions.

Causes include equipment faults, inadequate maintenance, damaged insulation, loose connections, moisture, and improper work practices. Hazards include severe burns, eye and hearing damage, and blast injuries from the pressure wave and flying shrapnel. Even seemingly routine tasks can trigger an arc flash if proper precautions are not followed.

Standards and evaluation: Safety in many jurisdictions relies on standards such as NFPA 70E Electrical Safety in the Workplace and IEEE 1584, which guide arc‑flash hazard analysis. The hazard is assessed by calculating incident energy at a working distance and defining an arc flash boundary. Incident energy is expressed in cal/cm^2, and the boundary denotes where the energy level reaches a specified threshold.

Prevention and protection: Engineering controls (enclosures, interlocks, maintenance, proper grounding) reduce arc flash likelihood and severity. Administrative controls include training, procedures, and permit-to-work systems. Personal protective equipment is selected based on anticipated incident energy and includes flame‑resistant clothing, arc‑rated face protection, gloves, and hearing protection. Arc‑flash labels provide the incident energy, boundary, and required PPE.

Response: The goal is to de‑energize equipment and restrict access before work. In case of a burn, seek immediate medical attention; provide first aid and follow local medical protocols.