What are the characteristics of the second-class building fire power supply system?

The power supply system of Class II building (Class II fire load) is as follows. Two power sources of a class of buildings should be automatically switched at the last distribution box. The main power supply is the normal power supply of the automatic fire alarm system, and its voltage deviation should be within the allowable range of the fire alarm controller, otherwise voltage regulation measures should be taken. The main power supply usually adopts AC 380 V/220 V When the number of detection areas in the alarm system is less than 10, all circuits are considered to be in alarm state. When the number of detection areas in the alarm system is 10, it is considered that 20% of the detection areas (but not less than 10) are in alarm state, and the rest are in monitoring state. Fire power supply (including fire power supply, fire power distribution, fire lines and electrical devices, etc.). ), fire emergency lighting and evacuation signs (including fire emergency lighting, evacuation signs and auxiliary evacuation signs). Civil building fire fighting equipment mainly includes fire pump, smoke exhaust fan, positive pressure fan, fire elevator, fire damper, fire shutter door and gas fire extinguishing device.

The rationality of power supply and control flow of fire fighting equipment is an important guarantee to ensure the normal function of fire fighting equipment in case of fire. It is an effective method to reduce the fire loss to the minimum range. Main power wiring should pay attention to the following matters: fire power distribution equipment should be clearly marked and separated from ordinary power distribution equipment. The shunt feeding from the switchboard should be controlled by horizontal or vertical fire protection zones, and the fire-fighting electrical equipment should adopt radial distribution scheme to reduce the influence of faults. Fire-resistant and heat-resistant cables and wires should be preferred for the structure, device and internal wiring of fire-fighting distribution board; If not, its installation position should be as far away from the place where it is easy to catch fire as possible.