Get Wired 102 Introduction to the Basic Installation of Lighting Fixtures and Branch Circuits Practice Test

In a multi-wire branch circuit, the safety priority is that the two ungrounded conductors share a neutral and must be able to be disconnected together. Having a common trip or a handle-tied pair ensures that both hot conductors are de-energized at the same time when you shut off the circuit. This prevents a situation where one hot remains energized while you think the circuit is off, which could leave the neutral carrying unexpected current or expose you to shock. It also avoids neutral overcurrent scenarios that can occur if only one leg is disconnected.

For completeness, the two hot conductors should be on different phases so the neutral carries only the difference between the loads on each leg, not the sum. Bonding the neutral to ground at the panel is not correct for MWBCs in the panel (neutral-to-ground bonding occurs at the service equipment, not at the branch-circuit panel), and separate meters are not a requirement for this setup.