Where should emergency lighting circuits not be connected according to safety standards?

Emergency lighting circuits should not be connected to multiwire branch circuits due to safety and reliability concerns. Multiwire branch circuits involve multiple hot wires sharing a common neutral. In the event of a fault or if one branch disconnects, it can lead to imbalances and unexpected interruptions in power supply. This could cause emergency lighting systems to fail when they are needed most, such as during power outages or emergencies.

Keeping emergency lighting circuits separate ensures that they will operate independently, providing a reliable light source to help navigate safely during emergencies. This segregation aligns with safety standards aiming to maintain functionality and prevent interdependencies between systems that could compromise safety. Other circuit types, while they have their specific applications, do not pose the same level of risk to emergency lighting during critical situations.