A 120-volt, single-phase, 2-wire system is required to be what?

In the context of electrical systems, particularly regarding single-phase, 120-volt circuits, there are specific standards that dictate the requirements for installation and operation. A 120-volt, single-phase, 2-wire system is commonly used in residential and commercial applications for lighting and small appliances.

The phrase "required to be" signifies that such a system must meet certain code regulations for safe and effective operation. These regulations ensure that the installation adheres to the National Electrical Code (NEC) standards, which are established to protect individuals and property from electrical hazards. The NEC outlines the necessary guidelines for wiring installations, including those for voltage ratings, wire types, circuit breakers, and connectors, to ensure safety and reliability.

Therefore, a 120-volt, single-phase, 2-wire system being "required to be" indicates the obligation to follow these NEC standards during installation and use, underscoring the importance of adhering to the established electrical code in ensuring safety and functionality.