On a dwelling multiwire branch circuit connected to a duplex receptacle with split‑wired hot conductors and a common neutral, what requirement must be provided where the circuit originates?

• A. A means to disconnect simultaneously all ungrounded conductors must be provided where the circuit originates.
• B. A separate neutral disconnect switch is required.
• C. The neutral must be isolated at the receptacle.
• D. The hot conductors must have individual disconnects at the panel.

Answer: (A)

When a multiwire branch circuit shares a neutral, the two hot conductors must be treated as a single safety unit. If you could disconnect only one hot at a time, the other hot could still be energized and the neutral could carry current or become a shock path during servicing. To prevent that possibility, the code requires a means to disconnect all ungrounded conductors simultaneously at the circuit’s origin. In practice, this is provided by a two-pole breaker or two single-pole breakers with a common trip or handle tie in the panel, so both hot legs de-energize together. The neutral isn’t required to have a separate disconnect at the origin, and isolating the neutral at the receptacle isn’t the required safety measure. Individual hot disconnects without coordinated operation would still allow one leg to remain energized.