Journeyman Electrician Exam (NEC)Equipment and DevicesEasy

A technician is installing a 120-volt, 15-ampere general-purpose receptacle in a dry location within a commercial office building. Which of the following receptacle configurations is most commonly used and appropriate for this application in the United States?

  1. ANEMA 5-15R
  2. BNEMA 6-15R
  3. CNEMA 5-20R
  4. DNEMA 14-50R
Show answer & explanation

Correct answer: A. NEMA 5-15R

The NEMA 5-15R is the standard 120-volt, 15-ampere, three-prong (grounding) receptacle found in most residential and commercial general-purpose applications in the United States. The '5' indicates 125V nominal, '15' indicates 15 amps, and 'R' denotes receptacle.

Why the other options are wrong

  • B. NEMA 6-15R is a 250-volt, 15-ampere receptacle, not suitable for a 120-volt application.
  • C. NEMA 5-20R is a 120-volt, 20-ampere receptacle, identifiable by a horizontal slot at one end of the neutral slot. It's not for a 15-ampere circuit.
  • D. NEMA 14-50R is a 120/240-volt, 50-ampere receptacle, typically used for ranges or EV chargers, far too large for a general-purpose 15-ampere circuit.

NEMA Receptacle Configurations

National Electrical Manufacturers Association (NEMA) standards define electrical receptacle and plug configurations for various voltage and current ratings.

  • Identifies voltage, amperage, and grounding type.
  • Ensures compatibility and safety.
  • Commonly seen as 'straight blade' or 'locking' types.

Memory trick: NEMA: Number, Amps, Volts, and Ready for Use.

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