Electrical Hazards
The four main electrical hazards: electrocution, electrical burns, arc flash/blast, and fires from electrical faults. Even 120V household current can be fatal. Voltage is not the only factor — current through the body determines injury severity. As little as 100mA can stop the heart.
NFPA 70E & Arc Flash
NFPA 70E establishes electrical safety work practices. An arc flash can produce temperatures up to 35,000°F — hotter than the sun's surface. Arc-rated (AR) PPE is required within the Arc Flash Boundary. NEVER work on energized equipment without proper PPE and authorization.
Approach Boundaries
Limited Approach Boundary: unqualified persons must stay outside. Restricted Approach Boundary: qualified persons only, with PPE. Prohibited Approach: treated as contact with energized part. These boundaries are labeled on electrical equipment and calculated per NFPA 70E tables.
Job Site Electrical Safety
Use GFCI protection on all 120V temporary power. Inspect all cords before use — no splices, no damaged insulation. Keep cords out of water. Never drive over cords. Use cord covers in walkways. Temporary power must be installed by a licensed electrician. Report any exposed wiring immediately.
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