What is a switch rated for use in general distribution and branch circuits called?

A switch rated for use in general distribution and branch circuits is referred to as a general-use switch. This designation indicates that the switch is designed for standard applications in residential, commercial, and industrial settings, where it can safely interrupt electrical circuits under normal operating conditions.

General-use switches are built to comply with safety standards and performance specifications outlined in the National Electrical Code, making them suitable for widespread use in various installations. Their design incorporates features that facilitate safe operation, including ease of manual operation and reliable performance over time.

In contrast, other types of switches listed, such as isolating switches, are intended for specific applications, often in situations where equipment needs to be separated from the power supply for maintenance. Branch circuit switches usually refer to switches specifically implemented within branch circuits, which might not cover the broader requirements of general-use definitions. Lastly, main service switches are used to control the power supply to an entire premises, rather than just branch circuits. These distinctions highlight why the term "general-use switch" accurately encapsulates the intended functionality and application identified in the question.