Yes, emergency lighting can be dimmed, but with important caveats and specific requirements, mainly concerning safety and legal compliance.
Here are the key points:
- Normal Operation (Mains Power Present):
- Maintained Emergency Lighting can often be dimmed as part of the normal building lighting system to save energy or set a mood (e.g., in theaters, hotels, or restaurants).
- Various dimming technologies can be used.
- The control gear inside the luminaire must be dimmable.
- Emergency Operation (Power Failure):
- Crucial Requirement: In the event of a power failure, all emergency lighting must automatically switch to full, un-dimmed output to provide the minimum required illumination (measured in lux) for safe evacuation as specified by the standards.
- Specific Exceptions (Charge Indicator Dimming):
- Most emergency lights have a small charge indicator LED (green). This cannot be dimmed.
In summary, dimming is possible during normal use, but the safety function must always override the dimming control to ensure full illumination during an actual emergency.
