On construction sites, NEC requires that all 125-volt, 1Ø, 15-, 20-, and 30-amp temporary receptacles have what protection?

• A. Ground-Fault Circuit Interrupter
• B. Arc-Fault Circuit Interrupter
• C. Inrush Current Limiter
• D. All of these

Answer: (A)

The main safety concept is protecting workers from electric shock by detecting ground faults and cutting power fast. For temporary 125-volt, single-phase receptacles used on construction sites, the NEC requires Ground-Fault Circuit Interrupter protection. A GFCI constantly monitors the current going out and coming back through a circuit; if it detects even a small difference (typically around 4–6 mA) it trips almost instantly, stopping the power before a person can be seriously shocked. On construction sites, where cords, tools, and moisture raise the risk of ground faults, this rapid shutoff is essential.

The other protections aren’t the NEC requirement for these temporary site receptacles. Arc-Fault Circuit Interrupters guard against fires from arcing faults, which isn’t the specific hazard being prioritized here. An inrush current limiter doesn’t provide fault protection; it just limits surge currents and isn’t a safety device for preventing shock. So the correct protection is GFCI, making “All of these” inaccurate.