What is a service disconnect and its typical requirement?

• A. A main switch that disconnects a single circuit; must be accessible
• B. A main switch or device that disconnects all power; must be readily accessible, usually near the service entrance
• C. A device that connects to the service entrance
• D. A fuse box for lighting

Answer: (B)

The main idea here is what a service disconnect does and where it should be placed. A service disconnect is the main switch or device that can shut off all electrical power to the building. It should be readily accessible, usually located near the service entrance, so anyone can quickly disconnect power in an emergency or for safety during work.

This is the best choice because it captures both the scope of the disconnect (it stops power to the entire building) and the practical placement requirement (readily accessible near the service entrance), which are the defining features used in standards and practices.

The other options don’t fit because they describe devices that either affect only a single circuit, or merely connect to the service entrance, or pertain to a fuse box for lighting—none of which provide the universal shutoff for the whole building that a service disconnect is meant to provide.