What is the maximum nominal voltage that can be supplied between conductors for luminaries in dwelling units?

The maximum nominal voltage that can be supplied between conductors for luminaires in dwelling units is 120V. This is established within the National Electrical Code (NEC), specifically regarding the safe operation of lighting circuits.

In residential settings, common lighting systems are designed to operate at this voltage level, which balances efficiency, safety, and compatibility with typical household appliances and fixtures. By limiting the nominal voltage to 120V, the code helps to minimize the risks associated with electrical shock and fire hazards, making it safer for common residential use.

Higher voltage levels, such as 240V or 480V, are generally reserved for specialized circuits or commercial applications where higher power is needed, which are not typically used for standard luminaires in dwelling units. Similarly, 60V is below the standard for typical residential lighting, which is why 120V is recognized as the standard voltage for luminaires in these environments.