What is required when a multiword branch circuit is connected to a duplex receptacle using an ungrounded conductor?

When connecting a multiword branch circuit to a duplex receptacle using an ungrounded conductor, it is important to provide a means to disconnect all ungrounded conductors. This requirement is rooted in safety standards aimed at ensuring that when maintenance or servicing is performed on the circuit, there is a clear and reliable way to disconnect the power. An effective disconnection method helps prevent accidental electrical shocks or equipment damage during work on the circuit.

The necessity for a means of disconnection applies particularly in residential and commercial settings where circuits may serve multiple loads, making it crucial to safely manage the power supply. This aligns with best practices in electrical code compliance, ensuring that all ungrounded conductors can be safely isolated from the power source.

In this scenario, the other options do not adequately address the need for a safe disconnection method for all ungrounded conductors. While grounding methods and protective devices are essential for overall electrical safety, they do not directly fulfill the specific requirement highlighted in the question regarding disconnection.