Emergency lighting switches on automatically when a
building experiences a power outage. In addition to illuminated exit and
emergency directional signs, products include automatic, standby,
emergency, and auxiliary electric power equipment of all voltages that
incorporate a charging means, a battery, and a switchover device to
activate emergency and egress lighting when the power goes out.
lights and exit signs consist of a lighting source, a device to focus
and intensify the light, a backup power supply, and a test function. The
lights consist of clusters of high-intensity light-emitting diodes
(LEDs). Battery backup ballasts may be installed to automatically switch
into emergency mode. Modern fixtures may also include a small
transformer that steps down the voltage from main current to the
required low voltage.
Through NEMA, Members promote reasonable,
repeatable, and unburdensome product test procedures and performance
criteria that are required for regulatory bodies and certification labs.