Emergency lighting is an important safety facility for modern public buildings and industrial buildings. It is closely related to personal safety and building safety. When a building has a fire or other disaster, accompanied by a power outage, emergency lighting has an important role in personnel evacuation, fire rescue work, and the continued operation or necessary operation and disposal of important production and work. Some developed countries and the International Commission on Illumination (CIE) have set high requirements and detailed regulations.
In recent years, many high-rise public buildings and foreign-related buildings have been built in China, and the role of emergency lighting has become increasingly prominent, which has attracted the attention of fire departments and design units. However, China still lacks perfect and detailed standards and norms. The "Civil Building Lighting Design Standards" (hereinafter referred to as "People's Standards") and "Industrial Enterprise Lighting Design Standards" (hereinafter referred to as "Workmarks") have only very principled provisions.
In 1993, the China Lighting Society released the "Guide to Emergency Lighting Design", which absorbed advanced international standards, summed up the experience of China, and has certain guiding significance for design.
Now I will talk about my own understanding of several issues in emergency lighting design.
The name and classification of an emergency lighting
Since the 1950s, China has been using the term "accident lighting". In order to interface with the word "Emergency Lighting" commonly used in CIE and the United States and the United States, and considering more precise and more realistic, "Popular Standards" and "Workmarks" promulgated in the early 1990s have used "emergency lighting". ". The change of nouns is accompanied by some changes in content and technical requirements. For example, past accident lighting is divided into two categories, namely, accident lighting for evacuation and continuing work; and the emergency lighting specified by the new standard is divided into three categories, namely, evacuation lighting and safety.
Lighting, backup lighting. This three-category approach is consistent with CIE's Guide to Emergency Lighting in Buildings. However, the classification of countries is not uniform, such as the Netherlands and CIE; the United States "personal safety regulations" are divided into four categories, that is, evacuation lighting is divided into two categories, therefore, and CIE classification is closer; and the former Soviet Union and the United States norms still Is divided into two categories;
Judging from the situation in the past two years, some designers are still not very clear about the classification and its meaning, which makes the engineering design not meet the requirements. Therefore, it is necessary to understand the meaning, function and how to design each of the three types of emergency lighting, especially the role of evacuation lighting. The function of evacuation lighting shall provide the evacuation passage with the necessary illumination for walking towards the exit direction and shall clearly mark the exit position. According to these functions, evacuation lighting friends should be divided into two categories: one is evacuation lighting, etc. - providing the necessary illumination for the evacuation channel; the second is the evacuation indicator light - for the sign and indicating the exit. The functions of these two types of lamps are different. The form and installation position of the lamps are different and cannot be confused. In particular, the evacuation indicator light, there are many internationally common expressions and technical requirements, and can not be applied at will.
Illumination of emergency lighting
The new "Popular Standards" and "Workmarks" have a principled comparison. There are also some problems in the design. Since the illumination illumination is mostly low, the uniformity is generally not high, and the average illumination is very different from the minimum illumination. In addition, the entire site is required to have certain parts and regions with the specified illumination, which is not the same.
Illumination is high and low, in addition to visual conditions, it is also related to the economic level and energy conditions of a country.
Evacuation illumination, the US regulations are not less than 10Lx (can be reduced at the end of the duration)
6Lx), Japan regulations are not less than 1Lx (not less than 2Lx when using fluorescent lamps), and CIE does not specify
Less than 0.2Lx. China's "workmark" requires that the main evacuation channel should not be lower than 0.5Lx. The fire code requires that the minimum illumination should not be less than 0.5Lx. The illuminances specified by the two are the same, but the actual difference is very large. The "working standard" uses the average illuminance, while the main channel is specified, and not all is required.
Considering the actual situation in China, with reference to the CIE and US regulations, it is recommended that the billing system generated at least on the ground centerline of the evacuation channel should not be lower than 0.5Lx. And should maintain a good uniformity.
As for the illumination of safe lighting and standby lighting, the "Workmark" regulations should not be lower than 5% and 10% of general lighting. This is a general principle. I think the following two characteristics should be considered in the design and treated differently:
The first is that certain areas should be illuminated. For example, the operating table should maintain the same illumination as normal lighting. Some important public places, such as the International Conference Center, the International Competition Stadium, and the Fire Command Center, should have The same illumination as normal lighting.
The second is the standby and safety lighting in some places, such as the fire control room, generator room, distribution substation, etc., mainly to ensure the necessary work and the required illumination of the operating parts, without requiring the entire room or place to achieve the specified uniformity.
Conversion time and continuous working time of three emergency lighting
These two standards are not specified in the "Workmark" and "Public Standards". The requirements are as follows according to the CIE requirements.
1. Normal power interruption, conversion time to emergency power supply:
(1), evacuation lighting, should not be greater than 15S. This is considered to adapt to emergency generators
Starting conditions, such as the use of other emergency power sources, should strive for shorter.
(2), safety lighting, should not be greater than 0.5S. Because the personal safety is more direct and the requirements are higher, the emergency power supply can only use the automatic conversion of the grid line or the battery.
(3), standby lighting, should not be greater than 15S. For production sites with explosion hazards, depending on the characteristics of the process, determine the shorter time as needed; for places such as checkout counters in shopping malls, to prevent theft, it should not be greater than 1.5S.
2. When the emergency power supply is used, the emergency lighting duration requirements:
(1), evacuation lighting, should not be less than 30min. It should mainly consider the time required for personnel to evacuate, search for people in the building, rescue, etc. in the event of a fire or other disaster. For super high-rise buildings, large-scale multi-storey buildings, large hospitals, etc., longer durations such as 45, 60, and 90 minutes should be considered.
(2) Safety lighting and standby lighting shall be determined according to the production, process characteristics and duration. Public buildings, communication centers, broadcasting stations, television stations, power generation and distribution centers, transportation hubs, etc., which are particularly important, should continue to work for a long time.
Four emergency lighting power supply
1. As the power source for emergency lighting, there are mainly the following categories:
(1) A line from the power grid separate from the normal power source;
(2) Emergency generator set;
(3) The battery pack includes three types of battery packs that are centrally set, partitioned, and included in the emergency light;
(4) At the same time, there are two or three combinations of the above three types of power sources.
2. Characteristics and applications of backup power from the power grid
This form of application is common, fast, reliable, and long lasting. In large and medium-sized cities, large and medium-sized factories, etc., it is often easier to obtain such power. Generally speaking, in public buildings and factories, due to production and work needs, when there is a grid backup emergency power supply, it is first used as an emergency lighting power source. Conversely, it is not economical and reasonable to set up for emergency lighting. Therefore, when designing, the power supply and emergency power supply of power equipment and emergency lighting should be arranged in a unified manner in order to be economical and reasonable. For the standby lighting that continues to maintain production, the standby lighting of the fire pump room should be the same as the production power equipment and fire pump, which is generally taken from the power grid.
3. Characteristics and application of emergency generator sets
After the power supply is interrupted, it takes a long time for the emergency generator set to be put into operation. Units that are often in reserve state need about 15 seconds to start from power failure, so they can only be used as emergency power sources for evacuation and backup lighting. It cannot be used alone for security lighting. Generator sets designed for emergency lighting are usually uneconomical and unreasonable. In high-rise buildings, it is often set up for fire protection requirements. For example, in Hong Kong, public buildings with more than 8 floors should be equipped with generator sets for emergency power supply; in some industrial production plants, communication and traffic orders are often associated with production and operation of power facilities. Need to think together.
4, battery pack characteristics and applications
The battery has high reliability and rapid conversion, and can adapt to various types of emergency lighting. The disadvantages are small capacity, short duration, frequent maintenance checks, important public buildings, important underground buildings, and sometimes other emergency power supplies; in small public buildings, such as small hotels, when it is difficult to obtain backup power from the grid. It is more cost-effective to use batteries.
The power supply unit (UPS) is a centralized or centralized battery power supply mode. Its performance indicators are high, but the price is also high. Generally, emergency lighting should not be used. However, when there is a UPS in a building such as a computer station, and the capacity can meet the requirements, it is suitable to use the UPS to supply emergency lighting in the site. When the central power distribution station is equipped with a battery DC screen, it can be used to supply standby lighting in the premises.