Emergency lighting applications

Abstract: This article discusses the specification of emergency lighting in detail and discusses the design requirements of emergency lighting such as evacuation lighting, safety lighting and standby lighting. Whether to cut off the supply of emergency lighting and fire, they put forward their own views, and discusses the emergency lighting line laying, emergency lighting requirements to be followed.

Keywords: civil architecture, emergency lighting, evacuation lighting, safety lighting, backup lighting, fire emergency lighting

GRS Fire Protection Lifeline

First, the content of emergency lighting:

The International Electrotechnical Commission's IEC "Emergency Lighting Fixtures" standard divides emergency lighting into evacuation lighting and back-up lighting. China's " Imprinting " and "Civil Building Electrical Design Code" ( JGJ16-2008 , hereinafter referred to as the new "Public Regulations") will respond Lighting is divided into evacuation lighting, security lighting and spare lighting.

In the fire code “High Building Design Code for Fire Protection of Civil Buildings” (GB50045-95 ( 2005 edition), hereinafter referred to as “High Regulations” ) and “Building Design Fire Protection Code” (GB50016-2006 , hereinafter referred to as “Low Regulations” ) , To emergency lighting, call it "fire emergency lighting." Due to the continuous occurrence of fires in recent years, the concept of the design engineer's reference to emergency lighting is considered to be emergency lighting under fire conditions. In fact, the extension of the emergency lighting referred to in “Impulsion” is larger than fire emergency lighting, because the failure of normal lighting power supply should include the normal power supply blackout, or the normal power supply in case of fire, earthquake and other emergency situations. Therefore, the design of the emergency lighting system not only needs to meet the fire emergency lighting system requirements set by the fire protection code, but also meets the requirements of each standard or standard for the overall emergency lighting system.

Second, the understanding of evacuation lighting:

According to the interpretation of the standard, evacuation lighting, as part of emergency lighting, is used to ensure that safe exit corridors can be effectively identified and applied, allowing people to safely evacuate buildings. From the perspective of the use of functions, the author believes that it can be divided into evacuation signs and evacuation of emergency lighting. The evacuation indicator lamp is used to identify the direction of the safety exit and the location of the safety exit. The evacuation emergency lighting is used for the channel to be effectively used to prevent people from colliding with obstacles, and can easily find the fire alarm button, fire fighting equipment and the evacuation route. Distribution box and so on. According to the Regulations, the illuminance of evacuation lighting on evacuation passages should not be lower than 0.5lx . According to the regulations of “High Regulations” and “Low Regulations”, emergency lighting for evacuation shall have a floor illumination of not less than 0.5lx . "Lower regulations" and the new "Public Regulations" have more specific provisions. Summarize the provisions of each specification and standard, and sum up the illumination requirements for evacuation lighting as follows:

1. The minimum level of illuminance on the evacuation aisle should not be lower than 0.5lx ;

2. Personnel-intensive areas (such as the audience hall, exhibition hall, multi-functional halls, restaurants, waiting rooms, business halls, and office halls in high-rise public buildings) and underground evacuation areas (with more than 300 square meters underground The lowest level of illumination on the ground within buildings) shall not be less than 5.0lx ;

3. The floor minimum illuminance in the vertical evacuation area (such as stairwells) should not be lower than 5.0lx ; in addition to the evacuation corridor lighting, the above places should also be set up at each safety exit and evacuation walkway to set safety exits respectively. Signs and evacuation walkway signs;

Third, the understanding of alternative lighting:

The interpretation of the alternative lighting in the “Impulsion” is as part of emergency lighting to ensure that normal activities continue. It also stipulates that the illumination of standby lighting ( excluding fire-fighting equipment room, power distribution room and self-provided generator room ) should not be less than 10% of the general lighting illumination .

Fourth, emergency lighting power supply:

The new "Public Regulations" 13.8.5 stipulates: After the emergency lighting stops supplying power in the normal power supply, the emergency power supply switching time should meet:

Evacuate lighting ≤ 5s , spare lighting ≤ 5s , financial commercial trading site ≤ 1.5s

In order to meet its requirements, the emergency lighting power supply has a clear requirement in the new "Public Regulations", mainly to grasp the load classification of fire-fighting electricity, and then according to the fire protection zone (double power supply) emergency lighting distribution box, there are two specific Form: One is a decentralized power supply system, ie each emergency light comes with a backup power supply. When the normal power is cut off, the standby power is automatically turned on. The other type is a centralized power supply system. The emergency light itself does not have a power supply. When the normal lighting power supply fails, a dedicated centralized emergency power supply is used to provide power. The system needs to set up independent power supply lines and power distribution equipment.

In fact, because of the influence of the conversion time and the power supply time of the emergency lighting power supply, the combined power supply methods of the above two or three types of power supply will be more reasonable and reliable in the design. analyse as below:

1. When using only a distributed power supply system, all emergency lights must have their own backup power supply. The advantages are high reliability of power supply, rapid conversion, convenient increase and decrease, no effect on line failure, and small impact on battery damage. The three-stage load is particularly suitable for emergency lighting that requires power. Disadvantages are large investment, high operational management and maintenance requirements, and limited power supply capacity.

2. When using only the centralized or partitioned battery power supply mode, the advantages are high reliability of the power supply, rapid conversion, less investment compared to the self-contained battery system, and convenient management and maintenance. The disadvantage is that it requires a dedicated room and the battery is faulty. The impact is large, and the line must consider fire protection issues, and the power supply capacity is limited.

3. When the independent power supply from the power grid supplies power, two external power sources are required to be powered by the external power supply to ensure that the other path can continue to work when a fault occurs. In this way, the power supply capacity and power supply time are not limited, and the conversion time can easily meet the requirements. However, in the event of a major disaster, the reliability of its power supply may be damaged, and the role of emergency lighting power supply may be lost.

4. When powered by a diesel generator set, the generator is required to have a self-starting function. The startup and commissioning time is less than 30 seconds . The emergency lighting distribution system is self-contained. The advantage of diesel generator power supply is that the power supply capacity and power supply time are basically unlimited. The disadvantage is that the conversion time is long, and it cannot be used for safety lighting and some spare lighting that requires high conversion time.

Therefore, I believe that: there are few emergency lighting, small scale, according to the three-tier load requirements of the building can be distributed power system, and other buildings, especially high-rise buildings should adopt self-starting diesel generator sets as the main power supply for emergency lighting The mode or backup power supply mode ( startup and commissioning time is less than 30 seconds) , emergency power supply type emergency lighting for emergency lighting, such as emergency evacuation signs, fire emergency lighting, safety lighting and financial commercial trading sites, etc. Lighting fixtures are used as transition lighting to meet the conversion time requirements.

V. Line laying of emergency lighting:

When the emergency lighting system is powered by the three-level load requirement, there is no special requirement for its power supply line, but it should be an independent circuit and cannot be the same circuit as general lighting. For emergency lighting systems that supply power at the secondary and primary loads, according to the requirements of various codes and standards, emergency lighting distribution should use dedicated power supply system wiring. Because it is necessary to consider investing in emergency lighting in the event of a fire, its distribution lines and control loops should be divided by fire zones. In addition, the following fire prevention measures should also be taken: When using dark laying, it should be laid in the non-burning body structure, and the thickness of the protective layer should not be less than 3cm ; when using the open laying, the metal pipe or wire trunk should be coated with fireproof coating Protection; When using insulated and sheathed cables with non-flammable materials, they may not be protected by metal pipes, but they should be laid in cable wells.

Sixth, emergency lighting fixtures:

Emergency lighting must use light sources that can be activated instantaneously. Only emergency lighting is used as part of normal lighting, and when emergency lighting and normal lighting do not occur at the same time, other light sources can be used for emergency lighting because light sources that do not start instantaneously ( such as when gas discharge lamp), when it is not used in conjunction with normal lighting operations, in case of accident, not instantaneous light.

In addition, the emergency lights should meet the safety technical requirements set by the relevant departments. As an emergency evacuation indicator light, it should also meet the following requirements: The safety exit sign light and the evacuation indicator light shall be fitted with protective covers of glass or non-combustible materials.

Seventh, emergency lighting power off

Emergency lighting is a comprehensive safety facility, and not all of them are used in fires and should meet the fire safety requirements. "Automatic fire alarm system design specification" (GBJ116-98) .8 section 6.3.1 states: "After confirming fire control room fire, should be able to cut off the relevant parts of the non-fire power, and turns on the emergency lighting and fire warning device Lamps and evacuation signs In the actual design, emergency lighting is often arranged in conjunction with normal lighting, using part or all of the normal lighting as emergency lighting, when a site fire, forced start or maintain emergency lights, indicating that people evacuated At the same time, cut off the non-fire power supply of the relevant parts to prevent the short circuit of the electrical circuit and facilitate the rescue work.Understanding the definition of emergency lighting, evacuation lighting, safety lighting, standby lighting and fire emergency lighting is the key to clarify the load level of the building is the basis, Doing these two things well will ensure that we will apply targeted regulations or technical measures in the design and design this part correctly.

Reference standards . :

[1] "Civil Building Electrical Design Code" ( JGJ16-2008 ) [S]

[2] Architectural Lighting Design Standards (GB50034-2004) [S]

[3] "Design code for fire protection of high-rise civil buildings" [S] (GB50045-95) ( 2005 edition) [S]

[4] “Code for Fire Protection of Architectural Design” (GB50016-2006) [S]

[5] "Fire Automatic Alarm System Design Specification" (GB50116-98) [S]

The information in this article comes from the Internet and was reorganized and edited by China Rescue Equipment Network.