Standard classification and purpose of emergency lighting
1. Purpose of emergency lighting:
Regular lighting The design is to make better use of the space, and the design takes into account all aspects of the interior. The purpose of emergency lighting is only one, that is, when the general lighting of the building is not working properly, it can make the people inside safely evacuate, so it should be at a specific time. Provide minimum illumination for designated safe passages, in addition to illuminated signs to aid safe evacuation, and clearly indicate the change in direction of each passage.
2. Emergency lighting standard:
GB17945–2000 Fire emergency lighting
This standard was released in January 2000, Implemented in October, it should be said that it is a relatively new standard. This standard is suitable for the installation of fire emergency lamps in general industrial and civil buildings, and fire emergency lamps with special performance installed in other environments. Except for special requirements, which should be specified by relevant standards. , should also implement this standard.
3. Classification of emergency lighting;
1) According to the form of emergency power supply:
a. Self-contained power supply type
b, centralized power supply type
c, mother and daughter power supply type
2) According to the purpose, it is divided into:
a, marker light
b, lighting light
c, lighting, marker light
3) Divided into:
a, persistent
b, non-persistent
4) Divided by emergency implementation For:
a, independent
b, centrally controlled
c, child-controlled
4. Requirements for emergency lighting
1) Requirements for illuminance
According to the CIE test results, people are very likely to encounter obstacles when the illuminance is below 0.2LX , In the case of 0.5LX, it can barely avoid encountering obstacles. The higher the illumination, the more confident people can move quickly and quickly. It is generally considered that it is more satisfactory if it is not less than 10LX or 10% of the normal lighting level. In addition, due to the sudden disappearance of normal lighting, the illuminance has dropped a lot. It takes a period of time for human eyes to adapt and restore automatic confidence. Generally, CIE also stipulates that the lighting ratio is 40:1. , the evacuation illumination should be increased to between 5LX-11LX.
2) Time requirements:
Our current fire emergency lighting conversion lighting time is generally about 1 second, which generally meets the requirements. At the same time, in order to help all personnel evacuate the scene, It needs a specific period of time, which is generally determined according to different places. Generally, the emergency lighting time is more than 1.5 hours.
3) Emergency lights and emergency lights should be used in combination, some only pay attention to the design of emergency lights, but ignore the design of emergency lights, or pay attention to emergency lights and ignore the design of emergency lights are unreasonable.
4) Emergency power supply and control:
①. After the building fires, it may cause short circuit of electrical lines and other equipment accidents. The fire spreads and expands, and it may also cause casualties due to touching the leaking live equipment or lines during the rescue. Therefore, after the fire occurs, the firefighters must first cut off the working power supply, and then put out the fire to ensure safety. Therefore, the power supply above 220V is used for emergency. The power supply is unreasonable because:
a. Unlike the general fire power distribution, the fire emergency lights are arranged in many locations and a wide area, basically involving the public places of the entire building, and the pipelines are arranged vertically and horizontally. , and most of the lamps are arranged in the ceiling. In reality, most of the emergency lighting pipelines have not taken any fire protection measures. Even if the pipelines have taken fire protection measures, the hoses, junction boxes, and terminals introduced into the lamps and lanterns will not be treated. Its lamps and lanterns should also be strictly treated with fire prevention, which is very difficult.
b. In the state of fire, the ceiling is very easy to burn. In this case, the pipeline is broken and the lamps are broken. At this time, the sprinkler system and fire protection system are working, and a large amount of water is injected along the floor plane and flows into each floor. To the area, the 220V power supply may pose a serious threat to the lives of evacuees and firefighters in the later period, and may cause the fire to spread to other areas due to the short circuit of the emergency lighting circuit.
C. Due to the complexity of the fire scene, the maximum possible situation will cause this part of the line to short-circuit, catch fire, and generate a large fault current, which affects the use of other fire-fighting electrical equipment or may spread the fire.
Based on the above analysis, it is unreasonable to use 220V city grid power supply, as well as generator set power supply or using transformer to change to 36V. It is better to use an independent emergency power supply.
②. One of the most basic principles of emergency lighting: that is, in the event of a fire accident, all evacuation signs and evacuation lights along the evacuation area, under the control of the fire center, are turned off. It should be started immediately after normal lighting, and should not be controlled by nearby switches. It should be kept in a state of direct lighting to facilitate the direct evacuation of personnel. It is very unrealistic to require emergency evacuation personnel to activate the lighting switch and then evacuate.
5. Structure and accessories of emergency lighting:
An emergency lighting fixture includes: a, light source b, charger c, converter d, It consists of six parts: battery e, ballast f, and lamps.
1) Light sources include:
a, incandescent lamps, incandescent lamps have been basically eliminated in emergency lighting due to their short lifespan and high power consumption , but still used in some maintenance-free double-head emergency lights.
b. Fluorescent lamps are generally used in emergency lighting. In the past, low-wattage fluorescent lamps were also used in some emergency evacuation signs. Due to other reasons such as light decay life, they were gradually used in emergency signs. A new type of electroluminescent film is replaced.
c. Electroluminescent film: It is a new type of luminescent material, which is made of the phenomenon that a certain appropriate solid interacts with an electric field to emit light. Due to its thickness and shape, the electroluminescent film can be changed at will, no heat is generated during the light-emitting process, the brightness can be changed with the change of voltage and frequency, the life span can reach more than 5000 hours, and it can work in harsh environments. , has a wide temperature range (-30 ℃ ~ +60 ℃), low power consumption and more and more attention and use, in emergency signs, is considered to replace incandescent lamps and small fluorescent lamps and other light-emitting devices ideal luminescent material.
d, LEd light-emitting diode; light-emitting diode is considered as a new type of light-emitting element, because of its strong light, long life span of more than 50,000 hours, and high brightness, it will be used in emergency signs and lights. Lighting has a bright future, but it is not widely used today due to its high cost and low power.
2) Batteries:
There are two kinds of power batteries for emergency lighting, lead-acid batteries and nickel-cadmium batteries.
Because of its low price, lead-acid batteries have been widely used in the previous emergency signs and lighting. Due to the poor shape of lead-acid batteries, heavy weight, short life, and long life. Due to the limited heat dissipation conditions inside the lamps, the current national standards have not allowed lead-acid batteries to be used in self-powered fire emergency lamps, but can only be used in centralized power type emergency lamps. Only sealed non-maintenance nickel-cadmium batteries or nickel-hydrogen batteries are allowed in current self-powered emergency lamps. Although the nickel-cadmium battery is more expensive than the lead-acid battery, it has a long life, can be charged more than 1000 times, and is more environmentally friendly.
3) Emergency converter:
The function of the emergency converter is to convert the low-voltage direct current provided by the battery into a high enough alternating current The lamp starts up and works normally, and the current emergency converters all use crystal devices to make the primary winding of the DC-powered transformer repeatedly turn on and off to obtain the AC voltage, so as to obtain the relatively high voltage required for the lamp to work from the secondary of the transformer. High voltage, in order to reduce the size of the transformer, avoid the problem of audio noise, and use the fluorescent lamp at high frequency, high working efficiency, the operating frequency of the inverter is usually above 20KHZ.
p>
