The emergency lighting system used in China is mainly of the independent control type with its own power supply. The normal power supply is connected to the general lighting power supply circuit, and the emergency light battery is usually charged. When the normal power supply is cut off, the backup power supply (battery) automatically supplies power. Each lamp of this type of emergency light has a large number of electronic components such as voltage transformation, voltage stabilization, charging, inverter, storage battery, etc. The battery needs to be charged and discharged when the emergency light is used, repaired, or malfunctions.
The other is a centralized power supply and centralized control type. There is no independent power supply in the emergency lamps. When the normal lighting power fails, the power is supplied by the centralized power supply system. In this form of emergency lighting system, all the complicated electronic circuits inside the lamps are omitted. The emergency lighting lamps are no different from ordinary lamps, and the centralized power supply system is set in a dedicated room.

Compared with emergency lamps with self-contained power and independent control, centralized power and centralized control emergency lamps have the advantages of convenient centralized management, user self-inspection, fire supervision and inspection, prolonged lamp life, and improved emergency evacuation efficiency. The system has good reliability and service life. Long, convenient maintenance and management, and low system price. However, because there is no backup power supply (battery) in each emergency luminaire with centralized power supply and centralized control emergency lamps, if the power supply line fails, it will directly affect the normal operation of the emergency lighting system, so special fire protection requirements are laid for the power supply line . Since each emergency luminaire has a backup power supply (battery) in the emergency lighting with its own power supply and independent control, there is no special requirement for the power supply line, and the power supply line failure will not affect the function of the backup power supply.
When the emergency lamp fails, it generally only affects the lamp itself, and has little effect on the entire system. When choosing emergency lighting, the emergency lighting system should be selected reasonably according to the specific situation. Generally speaking, for new projects or projects with fire control rooms, the wiring should be unified as much as possible during the construction process, and centralized power supply centralized control emergency lighting should be used; for small places, post-rectification or secondary decoration projects should be self-contained Emergency lighting with independent power supply.

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