Which safety switches are permitted to be used as the disconnecting means for a 240-volt, 1Ø water heater?

• A. I only
• B. II only
• C. I and II
• D. I, II, and III

Answer: (D)

Disconnection means must be listed, readily accessible, and capable of interrupting the circuit. For a 240‑V single‑phase water heater, you need a two‑pole disconnect to break both hot conductors. Any listed safety-switch configuration that provides a visible opening and is installed per its listing and the NEC requirements is acceptable as the disconnecting means. When a switch is properly rated for the load and located in an accessible spot, all the listed safety-switch configurations can be used, so the option that includes every permitted type is correct.