In the OFF position, a switching device with a marked OFF position shall ?

• A. Open all ungrounded conductors to the load it controls
• B. Open all grounded conductors to the load it controls
• C. Completely disconnect all ungrounded conductors to the load it controls
• D. Close all conductors to the load it controls

Answer: (C)

When a switch or disconnect is in the OFF position, the goal is to truly isolate the circuit by removing the energizing path to the load. The conductors that matter for this isolation are the ungrounded conductors (the hot lines) because they carry current. Completely disconnecting all ungrounded conductors guarantees there is no live path to the load, making the circuit safe to service.

Grounded conductors (like neutrals) are typically bonded to earth and are not required to be opened by the switch for safe de-energization; disconnecting them can create unsafe floating potentials and isn’t how these devices are intended to function. The option that would energize or reconnect the load is clearly incorrect.

So the best statement is that, in the OFF position, the device should completely disconnect all ungrounded conductors to the load it controls.