GFCI training is for anyone who uses portable power tools, extension cords, or electrical equipment in wet or temporary locations. That includes construction crews, maintenance technicians, electricians, and facilities staff. The 11-minute video, in English, explains insulation, grounding, and how ground-fault circuit interrupters protect workers from shock.

On construction sites, OSHA's 29 CFR 1926.404(b)(1) requires GFCIs on 120-volt, single-phase, 15- and 20-amp temporary receptacle outlets. The alternative is an assured equipment grounding conductor program, which requires daily visual inspection of cords and periodic testing. In general industry, ground-fault protection requirements appear in 29 CFR 1910.304.

A GFCI works by constantly comparing the current flowing out on the hot wire with the current returning on the neutral. A difference of about 5 milliamps means current is leaking through another path, such as a person. The GFCI then cuts power in a fraction of a second.

A standard circuit breaker protects wiring and equipment from overloads and short circuits, tripping at many amps of current. A GFCI protects people, tripping at a few thousandths of an amp of leakage current. A circuit breaker alone won't stop a shock that can kill, which is why GFCIs matter.

GFCI manufacturers generally recommend testing receptacle GFCIs monthly using the built-in test button. Portable GFCIs on job sites should be tested before each use. If a GFCI doesn't trip when tested, or won't reset afterward, take it out of service and have it replaced.