Electrocution is the third leading cause of death in NYC construction. Temporary electrical systems on construction sites — extension cords, spider boxes, power drops — carry full-voltage current and are subject to constant physical abuse from trades work. A Ground Fault Circuit Interrupter (GFCI) is the last line of defense between a fault and a fatality.

A GFCI monitors the difference in current between the hot and neutral conductors. If the difference exceeds 5 milliamps — meaning current is leaking to ground (possibly through you) — the GFCI trips in 1/40th of a second. That is fast enough to prevent cardiac arrest from electrocution in most cases.

• GFCI protection is required on ALL 120V, 15A, 20A single-phase temporary power used for construction
• This applies to every receptacle, every spider box, and every extension cord outlet on site — no exceptions
• Assured Equipment Grounding Conductor Program (AEGCP) is the alternative — but GFCI is easier and preferred
• GFCI devices must be tested monthly using the TEST/RESET button — document in the SSM daily log

• Use only cords rated for the load — check ampacity on the cord jacket; undersized cords overheat and cause fires
• Never use a cord with a damaged jacket, exposed conductors, or a missing ground pin
• Never splice extension cords with electrical tape — replace damaged cords
• Never run extension cords through doorways, windows, or holes in walls where the jacket can be pinched and damaged
• Never use household extension cords (light-duty) on construction sites — use SJTW, SJTOW, or equivalent hard-service cord
• Three-to-two adapters ("cheater plugs") are prohibited on NYC construction sites