Any single cord-and-plug-connected utilization equipment connected to a 20-amp branch circuit not fastened in place shall have a maximum rating of ___ amps.

Any single cord-and-plug-connected utilization equipment connected to a 20-amp branch circuit not fastened in place shall have a maximum rating of ___ amps.

• A. 16
• B. 10
• C. 20
• D. 25

Answer: (A)

The concept being tested is the 80% rule for cord-and-plug‑connected equipment on a branch circuit. When a single portable (not fastened in place) piece of equipment is connected to a 20-amp branch circuit, its rated current must not exceed 80% of the circuit rating to provide headroom for heat and potential continuous use. 80% of 20 amps is 16 amps, so the maximum rating for that equipment is 16 amps. Using a higher-rated device could overload the circuit or cause excessive heating in cords and connections. If you need to run equipment rated higher than 16 amps, you’d typically use a circuit arrangement that supports it (such as a fixed installation or a dedicated, higher-capacity circuit).

The concept being tested is the 80% rule for cord-and-plug‑connected equipment on a branch circuit. When a single portable (not fastened in place) piece of equipment is connected to a 20-amp branch circuit, its rated current must not exceed 80% of the circuit rating to provide headroom for heat and potential continuous use. 80% of 20 amps is 16 amps, so the maximum rating for that equipment is 16 amps. Using a higher-rated device could overload the circuit or cause excessive heating in cords and connections. If you need to run equipment rated higher than 16 amps, you’d typically use a circuit arrangement that supports it (such as a fixed installation or a dedicated, higher-capacity circuit).