ICC Residential Electrical Inspectors Practice Exam

What phase must be supplied by an individual branch circuit for electric vehicle outlets?

1. Double-phase

2. Single-phase

3. Triple-phase

4. Ground-phase

The correct answer is: Single-phase

Electric vehicle (EV) outlets generally require a single-phase supply from an individual branch circuit. This is primarily due to the common residential electrical configurations in North America, where single-phase power is typically used for standard household appliances and lighting. A single-phase circuit is adequate for most residential electric vehicle charging needs, as it can provide the necessary voltage and current to effectively charge electric vehicles. In most residential applications, the standard voltage for single-phase circuits is either 120 volts or 240 volts, with 240 volts being preferable for faster charging capabilities. In contrast, double-phase and triple-phase options pertain to more complex electrical systems that are not typically encountered in standard residential settings. Ground-phase is not a recognized phase type; rather, grounding is a safety feature implemented in electrical systems to prevent shock hazards and equipment failure. Therefore, the requirement for electric vehicle outlets to be supplied by a single-phase branch circuit aligns with residential electrical standards and ensures efficient charging solutions for electric vehicles.