Are circuits supplying only lighting required to be on separate branches?

Circuits supplying only lighting are indeed often required to be on separate branches, primarily to avoid overloading and facilitate effective circuit management. By having dedicated circuits for lighting, it ensures that the lighting load does not interfere with power for other devices that might draw significant current, which can lead to tripping breakers or even potential electrical hazards. This segregation of circuits allows for better reliability and safety in the overall electrical system, ensuring that lighting is consistently operable without being affected by the load from other appliances.

Additionally, separate circuits for lighting can aid in maintenance and troubleshooting. It becomes easier to identify issues within a specific circuit without affecting others, thus improving the overall efficiency of electrical management in both residential and commercial settings.

The other choices imply scenarios where lighting circuits could share branches with other loads, but this could complicate circuit management and potentially lead to safety issues if not monitored carefully.