What is the maximum voltage rating between conductors for branch circuits supplying receptacles for cord and plug connected loads of less than 1400 volt-amperes?

The maximum voltage rating between conductors for branch circuits supplying receptacles for cord and plug connected loads of less than 1400 volt-amperes is 120 volts. This is because the National Electrical Code (NEC) commonly utilizes 120 volts as a standard for residential receptacle circuits, particularly in dwelling units where most plug-connected appliances and devices are designed to operate at this voltage level.

Using 120 volts provides a safe and efficient distribution of electricity for typical household applications, such as lamps, kitchen appliances, and electronics. This voltage level is widely used in North American residential wiring, ensuring compatibility with most residential electrical devices.

In the context of receptacles for cord and plug connected loads, 240 volts and 480 volts are used for higher-power applications, typically found in commercial settings or for specialized equipment, and hence are not applicable for lower-load residential circuits. Similarly, while 208 volts is a common voltage rating for three-phase residential systems, it is not standard for single-phase residential receptacles powered by branch circuits under 1400 volt-amperes.