Emergency lighting can play a crucial role in egress during an emergency or power failure.
Emergency lighting is often referred to as egress lighting which provides a light source when a building experiences a power outage or failure. Emergency lights are required by code to be equipped with a battery or connect to a generation unit. The battery shall provide 90 minutes of illumination to safely evacuate the building incase of a fire or black out. Virtually every commercial and highly populated residential buildingis equipped with emergency lights.
A typical emergency light provides a high lumen with wide coverage. Most individual light heads can be rotated and aimed toward where light is needed most in an emergency, for example directed towards the Fire Exit Signs. Emergency light bulbs may be incandescent or halogen. Emergency light batteries are typically sealed lead acid which store a full charge of 120 volts. Emergency Light Batteries can last for 10 years or more on continuous charge. The emergency lighting heads are usually either PAR 36 sealed beams or wedge base lamps. All units have some sort of a reflector to focus and intensify the light they produce, much like a car headlight.
Modern emergency light fixtures usually have a test button of some sort that temporarily overrides the lighting unit and causes it to switch on the lights and operate from battery power even if the main power is on. Modern systems are operated with relatively low voltage, usually from 6-12 volts. This both reduces the size of the batteries required and reduces the load on the circuit to which the emergency light is wired.