What is the required illumination feature for emergency exit signs during a power loss?

Emergency exit signs are critical components of safety in commercial buildings, especially during power loss situations. The requirement for these signs is that they must remain illuminated even when the main power supply is interrupted. This ensures that occupants can clearly see the exit route in case of an emergency, such as a fire or blackout.

Being connected to an emergency power system means that the exit sign will automatically switch to a backup power source—such as batteries or a generator—when the main electrical supply fails. This capability provides a 24/7 safety net, ensuring visibility in crisis situations.

While battery-operated lighting could technically provide illumination, it is not solely sufficient in this context. Fluorescent lights and systems reliant on only main power would fail to meet the needs during an emergency, as they would either be inactive during a power loss or not guarantee sustained illumination under all circumstances.

In summary, connecting exit signs to an emergency power system is the most reliable method to ensure continuous and effective illumination of exit routes during power outages, fulfilling safety requirements and aiding in safe evacuation.