0 Preface Due to the deepening of people's common sense of safety and safety, personal injury accidents caused by electrical faults are decreasing year by year, but the number of fires caused by electrical accidents is increasing every year. This is in line with the trend that the total number of fires in China is decreasing year by year. sharp contrast. According to the data released in the 2005 China Fire Yearbook, the number of electrical fires accounted for 20.6% of the total fires, and there is a trend of increasing year by year. This requires us to investigate the causes, find the root cause and then use effective scientific methods to alleviate these. disaster. The electricity consumption per capita in developed countries such as Japan, Europe and the United States is much higher than that in China. Why is the probability of electrical fires occurring much smaller than that of China? The main reason is to set up a residual current electrical fire monitoring and detection system in important occasions. The application of leakage fire alarm system has been stipulated in China's national regulations. For example, the "Fire Protection Code for High-rise Civil Buildings" GB50045-95 (2005 edition) added the new 9.5.1: "High-rise buildings have high fire risk and personnel intensive It is advisable to set up a leakage fire alarm system in such places; "Code for Fire Protection of Building Design" Article 11.2.7 of GB50016-2006 specifies the place where the leakage fire alarm system should be installed. This paper discusses the selection and software functions of the fire detectors of the Leakage Fire Monitoring System project of the Tianshui Land and Resources Bureau, and hopes to help the design or selection of similar projects.
1 Project Analysis and Hardware Selection The office building of Tianshui Land and Resources Bureau belongs to the office building of the government agency and is located at No. 37, Lushan Road, Qinzhou District, Tianshui City. The office building has a total of 20 floors. There are 26 lighting distribution boxes, 20 emergency lighting distribution boxes, 2 ordinary elevator distribution boxes, 2 fire elevator distribution boxes, 2 fire pump distribution boxes, and 2 fire pump distribution boxes. 1 building power supply distribution box. It is now necessary to equip the building with a leaky fire monitoring system.
According to GB14287, the electrical fire monitoring system is divided into three parts: electrical fire monitoring equipment, residual current electrical fire monitoring detector, and temperature measuring electrical fire monitoring detector.
According to the national standard "Installation and operation of residual current action protection device" GB13955-2005 on the classification protection, when installing the residual current fire monitoring device, the reasonable distribution design of the fire prevention area in the building should be made to determine the appropriate protection scope and schedule. The residual current action value and the action time shall meet the requirements of the action characteristics of the hierarchical protection, and reduce the power failure range caused by the failure of the power supply. The principle of monitoring point allocation is as follows: According to the building power load and the specific conditions of the line, it is determined to adopt the secondary or tertiary protection mode; generally all the secondary switches must be equipped with residual current detection controller; important lines, including fire protection, security , emergency power supply, channel lighting circuit and important places that are not allowed to power outage, according to the provisions of GB13955 4.6, should install pure alarm type residual current detection alarm, alarm but not cut off the power supply (do not control tripping), not only ensure the safety of electricity The uninterrupted power supply is guaranteed.
According to the above basis, the project conducts leakage monitoring on a total of 33 monitoring points of five kinds of secondary switches of lighting distribution box, ordinary elevator distribution box, fire elevator distribution box, fire pump and building power supply line. Since the above switches are important lines and are distributed in important places where power failure is not allowed, it is necessary to select a model that does not control the tripping on the selection of the leakage fire detector. The ARCM200L-J1 leakage fire detector of Shanghai Ankerui Electric Co., Ltd. and AKH-0.66L residual current transformer are fully used to meet the requirements of leakage fire monitoring. The details are as follows:
1.1 Introduction of ARCM200L-J1 Residual Current Electrical Fire Monitoring Detector
1.1 Introduction of ARCM200L-J1 Residual Current Electrical Fire Monitoring Detector
1.1.1 Features: â— On-line monitoring of single-channel leakage current, phase cable temperature signal; â— Rated residual current action value (alarm), can be flexibly set according to needs, temperature action value (alarm) is also programmable; â— Screen The temporary function, when the leakage fault occurs, the channel display screen is reserved, indicating the value of the leakage or over-temperature of the channel, which is convenient for the fault record of the upper computer; â— Using the fieldbus communication technology, the upper computer management software can monitor the operation of the scene at all times. In case, the alarm information is found in time. Through the RS485 interface, the standard MODBUS protocol can be connected to various standard systems. â— The ARCM200L-J1 has an event storage function. The alarm can record the time, type and parameters of the alarm. According to the alarm record, the power consumption of the site can be analyzed. Fault supply basis; â— High integration, network, high degree of intelligence, reasonable operating characteristics; â— Suitable for 0.4kV voltage class TN-CS, TN-S and local TT system.
1.2 AKH-0.66L residual current transformer The rated current level of the residual current transformer should be greater than or equal to the setting current value of the distribution circuit protection appliance. In practice, ensure that all cables or copper bars pass through the transformer. The temperature sensor is a thermistor NTC, which provides a temperature monitoring reference of -10 ° C - 120 ° C, can be used to monitor the temperature inside the cable or distribution box, providing temperature protection, as shown in Figure 4 leakage of the project The monitoring points are 33 points, and the Acrel-6000/Q100 piano desktop leakage fire monitoring system can be used for the leakage fire monitoring software. The system can effectively predict and monitor the leakage and the fire caused by leakage, accurately monitor the faults and abnormal conditions of the electrical circuit, and can find the fire hazard of the electrical fire, promptly alert the personnel to eliminate these hidden dangers.
1: Alarm indicator (red), the indicator lights when the system receives the monitoring alarm signal.
2: Fault indicator (yellow), the indicator lights when the system receives the fault alarm signal.
3: Running indicator (green), the indicator lights when the system is running normally.
4: Main power indicator (green), the indicator lights when the main power is supplied.
5: Standby power indicator (green), the indicator lights when the backup power is used.
6: Silence button (black) to eliminate the alarm sound.
7: Manual output button (black), control the output of the protected line under the manual direct start alarm state.
2 System networking scheme The number of leakage fire monitoring points of this project is 33, which are distributed in the office building on the 20th floor of Tianshui Land and Resources Bureau. The selected leakage fire detector of the project is Ankerui products, adopting Modbus-RTU communication protocol and RS-458 interface. Modbus-RTU protocol theoretically, a bus can be connected to 32 RTU devices. Since this project needs to complete leakage fire monitoring, it plays an extremely important role in electrical safety and fire protection. To ensure the safety, stability and reliability of the leakage fire monitoring signal. The bus of this project only connects 16 or 17 tables, and is divided into two buses for data acquisition.
3 Leakage fire monitoring system function Acrel-6000 electrical fire system, real-time and timed collection of residual current data and temperature of field devices, and alarm prompt sound and light alarm and other functions, according to actual needs of the alarm temperature value, leakage current value Set, when the alarm is cleared, it can be reset remotely. The system can record alarm events, dates, alarm values, and crossing values, and generate reports to print alarm event records.
1) Fault information prompt When the monitoring device detects a device fault, the monitoring device will send out the following information. The software interface is as shown in Figure 5: the fault unit of the main interface for running monitoring displays a yellow background; the main screen of the running monitor displays real-time fault prompt information. The information content includes: time, device location, device number, fault information (the display interface is as shown below); in the "real-time information display area", "fault information" is displayed in yellow.
The yellow fault indicator of the monitoring device lights up and a fault tone sounds.
The leakage fire alarm system of Tianshui Land and Resources Bureau cooperates with ARCM200-J1 and AKH-066L to accurately monitor faults and abnormal conditions in electrical circuits, and to find out the fire hazards in electrical lines in time, which is of great significance in preventing fires.
4 Conclusion With the development of society, people's awareness of safe use of electricity is getting stronger and stronger, and the requirements for the safety and reliability of electricity use in some places are getting higher and higher. This requires that the market must have the appropriate quality hardware to meet this demand. At present, there are many manufacturers in the market that can provide such services. It is hoped that with the joint efforts of manufacturers and researchers, we will successfully curb the rising trend of electrical fires and reduce the disasters caused by electrical fires.
Wipes,Santary Paper
Wipes,Santary Paper
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