Understanding Emergency Light Circuit Sensing in Accordance with AS 2293

Emergency lighting plays a critical role in ensuring safety in the event of power failures in buildings. The AS 2293.1-2018 standard provides detailed guidelines for the design, installation, and operation of emergency lighting systems, including essential provisions for circuit sensing. This article explains the importance of circuit sensing and its application in accordance with AS 2293.1

What is Circuit Sensing?

Circuit sensing refers to the system's ability to detect the status of the normal lighting circuit. When the normal lighting fails or is interrupted, the emergency lighting system is triggered automatically to illuminate escape routes and critical areas, ensuring safety during evacuation. In simpler terms, circuit sensing ensures that emergency lights activate immediately upon detecting a loss of power in the main lighting system.

Importance of Circuit Sensing in Emergency Lighting

Circuit sensing is crucial in any emergency lighting system as it guarantees that lighting will be available during an emergency or power outage. Without it, building occupants may face increased risk, particularly in high-traffic environments like commercial buildings, offices, and industrial sites.

According to AS 2293.1-2018, emergency lights must be configured to activate automatically when the normal power supply is interrupted, without any delay. The standard sets stringent requirements to ensure that emergency lighting systems are reliable, and circuit sensing plays a pivotal role in meeting these requirements.

Emergency and Normal Lighting on Separate Circuits

In many installations, the emergency and normal lighting systems are placed on separate subcircuits to ensure independence and redundancy. This setup, however, poses challenges for circuit sensing, as the system must be able to detect failure on a different circuit. The AS 2293.1-2018 addresses this by requiring that emergency lighting systems be equipped with suitable sensing technology to detect failures in other circuits and respond accordingly.

This is especially important in complex or multi-zone buildings, where lighting systems are divided into various sections. In such cases, the circuit sensing feature ensures that emergency lights are activated only in the areas where normal lighting has failed, without unnecessarily triggering emergency lights in unaffected zones.

Key Requirements for Circuit Sensing in AS 2293.1-2005 to 2018

  1. Immediate Response: Emergency lighting must respond instantly to the loss of normal power, with no perceptible delay.

  2. Continuous Monitoring: Emergency lighting systems should continuously monitor the normal lighting circuit to detect any failures promptly.

  3. Subcircuit Integration: When normal and emergency lighting are on separate circuits, the system must be designed to sense failures across circuits.

  4. Testing and Maintenance: The standard also mandates regular testing of emergency lighting systems, including their circuit sensing functionality, to ensure continued reliability.

Emergency Light Reference

Conclusion

Emergency light circuit sensing is a vital safety feature that ensures the automatic activation of emergency lighting when normal lighting fails. Adhering to the requirements of AS 2293.1 ensures that emergency lighting systems in buildings are designed to operate reliably, protecting occupants during emergencies. When designed, installed, and maintained correctly, these systems significantly enhance building safety by ensuring lighting is available when it's needed most.

Jody Aldag