PSI Journeyman Online Practice Exam

Residential lighting circuits typically operate at 120 volts in many regions, particularly in North America. This standard voltage level is designed to safely and efficiently power common household lighting fixtures and appliances. It allows for compatibility with standard household outlets and fixtures, which are designed to handle this voltage.

Using 120 volts for lighting helps minimize the risk of electrical shock and fire hazards, as lower voltages are generally safer around the home environment. Higher voltage levels like 240 volts, 480 volts, or 600 volts are generally reserved for specialized equipment or industrial applications and are not suitable for typical residential lighting. This standardization ensures that homeowners can easily access and replace lighting fixtures without needing specialized training or equipment.