EMG Definitions


Maintained lighting system: An emergency lighting system requires two mains feeds: a permanent live connection and a switched live connection. The luminaire may be switched on and off with a healthy mains supply and the emergency control unit energises the lamp during a mains failure. The advantage of this system is that the luminaire can be used to provide normal lighting but the disadvantage is that the luminaire requires additional wiring.
Non-maintained lighting system: An emergency lighting system requires a single permanent mains supply. The luminaire cannot be used to provide normal lighting. In the event of a power failure the emergency control unit energises the lamp. The advantage of this system is that the lamp is not aged during normal mains conditions but the disadvantage is that the luminaire cannot provide normal lighting.
Self testing control unit: An emergency control unit that automatically conducts regular tests to establish the condition of the lamp and battery pack.
Stand-by lighting: Non-mandatory emergency lighting that is provided to enable normal activities to continue substantially unchanged.
Sustained lighting system: An emergency lighting system requires a single permanent mains connection. The fluorescent lamp is permanently energised from the mains supply and is powered by the emergency control unit during a power failure. The advantages of this system are that one live feed is required and the luminaire can provide normal lighting. The disadvantage is that the luminaire must remain on permanently.