Xu Shuang
Ankerui Electric Co., Ltd. Shanghai Jiading
Abstract The Ankerui residual current electrical fire monitoring system is used to monitor electrical fires in low-voltage distribution systems such as shopping malls, hotels, airports, banks, hospitals and factories through ARCM residual current electrical fire monitoring devices. This article focuses on the implementation of the Acrel-6000 electrical fire monitoring system in commercial real estate projects and its significance through the introduction of the Zhonghua Taohuayuan Electrical Fire Monitoring System project.
Keywords: fire detectors; electrical fires; commercial buildings;
0, foreword
In the past 10 years, the number of electrical fires in China has topped the total number of fire accidents. According to the statistics of the Fire Department of the Ministry of Public Security, there were 159,000 fires in 2007 (not including forests, grasslands, and underground fires in mines, the same below). From the direct cause of fires, electrical fires are the most common. Since then, it has accounted for 28.8% of the total. In 2008, there were 133,000 fires. Electrical causes such as electrical short circuits, overloads, and electrical equipment breakdowns caused 40,000 fires, accounting for 30.1% of the total. The proportion increased by 1.3 percentage points from 2007. The proportion of electrical fire accidents has increased year by year, which is worrying. For the severe electrical fire situation, early forecasting, early warning, and forecasting are the top priorities for firefighting, and eliminating the occurrence of electrical fires at the source has become the focus of attention. The task of preventing and effectively curbing electrical fires is imminent. Relevant experts actively called for the adoption of effective technical preventive measures as soon as possible to curb the rising trend of electrical fires. The relevant government departments also attached great importance to them and successively formulated or revised relevant standards and regulations and required the installation of a leakage fire alarm system in buildings. "High-rise Civil Building Design Fire Protection Code" GB50045-95 (2005 edition) Partial Revision Provisions 9.5.1, Mandatory National Standard "Installation and Operation of Residual Current Action Protection Devices" GB13955-2005 have emphasized that the residual current action protection device is preventing The protective effect of electrical fires caused by ground faults requires the installation of residual current action fire monitoring systems in buildings. It can be said that the prevention of electrical fires in buildings and the establishment of national standards and codes for electrical leakage fire alarm systems are basically complete (and other relevant regulations are being submitted for approval). In the future, there will be more and more relevant site design and application of electrical leakage fire alarm systems. Based on the new standard of electrical fire monitoring system (GB14827-2005) and the example of the Zhonghua Taohuayuan Leakage Fire Monitoring System, this paper introduces the application of Acrel-6000 electrical fire monitoring system in commercial buildings and large public places.
1. Project Introduction
Zhonghua Taohuayuan is located at Shenqian Road, Beihai Road, Xiangzhou District, Zhuhai City, close to beautiful bay. The project covers an area of ​​more than 40,000 square meters, with a total construction area of ​​approximately 121,000 square meters, and a building area of ​​approximately 89,000 square meters. This article focuses on China Shipping. The power distribution circuit in the distribution boxes on the 1st, 2th, 6th, 8th, and 9th floors of Taohuayuan is forecasted and monitored due to electrical leakage and leakage due to electrical leakage, and the faults and abnormal conditions of the electrical lines are accurately monitored, and electrical fires are discovered. Fire hazards, timely warning personnel to eliminate these hidden dangers. Help the airport save labor costs and improve work efficiency.
The system detects the leakage current, over-current, and over-temperature signals of each power circuit in the site and has audible and visual alarming to accurately alert the staff of the location of the line fault and monitor the change of the fault point. Store various faults and operation test signals, and display the system power status to effectively prevent common electrical fire accidents caused by electrical leakage and ensure the safety of people's lives and property.
2. Design basis of leakage fire monitoring system
The system complies with the People's Republic of China national standard GB14287.1-2005 "Electrical fire monitoring system - Part 1: Electrical fire monitoring equipment." In addition, “High-rise Civil Building Design Fire Protection Code†GB50045-1995 (revised in 2005) 9.5.1 stipulates that high-risk buildings within a fire risk, personnel intensive and other places should be set up a leakage fire alarm system; "Building Design Fire Protection Code" GB50016-2006 The 11.2.7 article store, theater, cinema, gymnasium and other personnel dense places should set up a leakage fire alarm system
3 related definitions of leakage fire monitoring system
With the development of technology, the traditional single-earth leakage alarm device has gradually evolved into a network-centricized electrical fire monitoring system. GB14287-2005 standard will be the original national standard "fire leakage current action alarm" GB14287-93 "fire leakage current action alarm" was renamed "electric fire monitoring system", and is subdivided into 3 parts, Part 1: Electrical fire Surveillance equipment, Part 2: Residual current electrical fire monitoring detectors; part 3: temperature-rated electrical fire monitoring detectors. The relevant definitions are as follows:
Electrical fire monitoring system: When the detected parameter in the protected circuit exceeds the set value, the system can send alarm signal, control signal and can indicate the alarm location. It consists of electrical fire monitoring equipment and electrical fire monitoring detector.
Electrical fire monitoring detectors: Detectors that detect changes in electrical fire hazard parameters such as residual currents, temperatures, etc., in protected circuits.
Electrical fire monitoring equipment: It can receive alarm signals from electrical fire monitoring detectors, can emit sound and light alarm signals and control signals, instruct alarm locations, and record and save alarm information.
4 The basic composition and working principle of the system
1, the basic components
According to the national standard GB14287-2005 "Electrical Fire Monitoring System" and related specifications "Design method of electrical fire monitoring system" (provisional regulations), the basic composition of the electrical fire monitoring system should include: electrical fire monitoring equipment, residual current electrical fire monitoring Detectors and temperature-based electrical fire monitoring detectors and other three basic product categories. Among them, the residual current type electric fire monitoring detector is again composed of a monitoring detector and a residual current transformer (a pair of plug-in type and a closed type); the temperature-type electric fire monitoring detector consists of a monitoring detector and a temperature measuring sensor. Made up of.
The residual current type electric fire monitoring system adopts a hierarchical distributed structure and is composed of a station control layer, a network communication layer, and a field device layer. The system topology is shown in the following figure: Each electrical fire monitoring probe is connected to the communication server through a shielded twisted pair RS485 interface, using a MODBUS communication protocol bus type connection, and then enters the monitoring host through the Category 5 TCP/TP protocol.
1) The field device layer is mainly used for various types of meters and protection devices used for leakage current and temperature signal acquisition and measurement in the connection network, and it is also a necessary basic component element for constructing the monitoring system. Not only shoulder the burden of collecting data, but also the terminal component that executes background control commands.
2) Communication control layer is mainly composed of communication server, interface conversion device and bus network. This layer is the bridge for data information exchange. Different interface conversion devices provide various interfaces such as RS232, RS422, RS485, SPABUS, and Ethernet, flexible networking methods, support for point-to-point communication, fieldbus networks, Ethernet, and other types. The configuration network. The communication server is mainly used to directly transmit various control commands of the host computer to the field instrument and meter, and is responsible for collecting, classifying, and storing the data information sent back by the field instrument, such as voltage/current and other electrical parameters and input switch status. , Modify the internal parameters of the instrument or various control relays open / close operation commands; interface conversion device is due to field instrumentation or other series of devices with the host computer's communication interface there are differences, need to be converted before data exchange.
3) Management The monitoring and control layer is for managers who monitor the network. This layer directly faces the user. This layer is also the uppermost part of the system, mainly by the electrical fire monitoring system software and necessary hardware equipment such as computers, human-machine interfaces, printers, UPS and so on. The software part has a good human-computer interaction interface. It reads the various data information collected by the front-end machine through the data transmission protocol, and is automatically calculated and processed to reflect the operating status of the site by means of graphics, digital display, and sound. Accept the operation command of the management personnel, send and check the execution status of the operation in real time to ensure the normal operation of the power supply unit.
2, the working principle
The basic principle is that when the current, temperature and other parameters in the electrical equipment are abnormal or abrupt, the terminal probe (such as the residual current transformer, temperature sensor, etc.) uses the electromagnetic field induction principle and the temperature effect to collect the information. And sent to the monitoring probe, after amplification, A / D conversion, CPU analysis and judgment of the change in amplitude, and compared with the alarm set value, once the set value is exceeded, then send an alarm signal, but also to the The monitoring equipment is further identified and determined by the monitoring equipment. When it is confirmed that a fire may occur, the monitoring host issues a fire alarm signal, turns on the alarm indicator, sounds the alarm, and displays the fire alarm and other information on the LCD. The on-duty personnel quickly checks and handles the accident scene according to the above information, and sends the alarm information to the centralized console.
3, design and installation of the monitoring system and wiring design
The alarm signals of the electrical fire monitoring equipment and system shall be located in the fire control room or the place where the personnel is on duty. The power supply of the host should be taken from the fire control power supply (AC220V) of the control center.
Each monitoring detector uses field power, and the power access point should be at the upper end of the circuit breaker.
1) Installation design of the internal form of distribution cabinet
This project is a new construction project. All the monitoring detectors are installed in the distribution cabinet in the substation, and they are embedded and installed on the panel of the distribution cabinet. The staff can check the leakage and temperature information of each circuit through the panel button. Residual current transformers shall be installed on the three-phase power lines A and B, C and N lines. The PE line shall not pass through the transformer and shall be firmly fixed. The connection between the detector and the transformer shall be shielded wire; the temperature sensor shall be A thermistor, NTC, provides a temperature reference of -10 to 120°C. The thermistor can be connected to an electrical leakage fire monitoring detector via a wire.
2) Installation design of the entire leakage fire monitoring system
Each leakage monitoring detector in the site has a 485 communication interface, and all the detectors on the site must be connected in series by means of a shielded twisted pair. When connecting, note that the number of connections per 485 bus does not exceed 32, and It is suitable for about 20. When installing the wiring, attention should be paid to the separation of strong and weak wires. The recommended wire diameter of the flame-retardant shielded twisted pair cable should be no less than 1.0mm2. The shielded wire shield layer should be well grounded, and each bus end should be increased by about 100 ohms. Matching resistance. Neat wiring, bundled into bundles, threading available flame retardant PVC pipe, metal pipe and metal trunking. After the pipe and slot are worn, the nozzle and slot shall be plugged.
4, product selection and introduction
There are a total of five buildings in the #1, #2, #6, #8, and #9 buildings, a total of 152 distribution boxes. According to the "Construction Electrical Fire Prevention Requirements and Testing Methods," the relevant provisions clearly require "to prevent electrical equipment. In case of a line leakage fire, a residual current operation protector that automatically shuts off the power supply or alarm should be installed at the power input terminal. Therefore, in this project, the leakage fire detector ARCM200-J1 and the residual current transformer AKH-0.66L are installed at the entrance of each distribution box, and the Acrel-6000/Q200, a benchtop electrical fire monitoring system, is established in the 8# building. Each building's electrical fire monitoring system is geographically distributed in five buildings. Each building also forms an organic whole through the 485 bus network. It shares the leakage and temperature information in various places and facilitates unified management by the staff.
ARCM200 series electrical fire monitoring detectors are intelligent detector products that comply with GB 14287-2005. The product can be used on a large number of online or stand-alone use (with leakage/overcurrent/temperature detection and alarm functions, and optional features: automatic shutdown of the monitored circuit during an alarm, ie relay output function). It integrates the functions of electrical fire monitoring and alarming. It is characterized by high intelligence, complete functions, reliable performance, mini design, beautiful appearance, simple setup, and instrumented installation. It is a crystallization of a refreshing new idea design and is another new contribution to preventing electrical fire accidents.
Electrical fire monitoring detectors (hereinafter referred to as "monitoring detectors") consist of residual current transformers, temperature sensors, and monitoring alarms. When the remaining current transformers in the protected circuit (hereinafter referred to as "transformer") detect the remaining When the current exceeds the preset value of the monitoring alarm or the temperature detected by the temperature sensor exceeds a preset value, the monitoring alarm device will issue an audible and visual alarm signal and a control signal after analysis and confirmation. The monitoring alarm can display the leakage current of the alarm circuit, sensor temperature and so on. When the monitoring alarm has alarm information, start the relay. It can directly display the detection current value and temperature value, without occupying a large equipment site, saving the cost of fire-fighting equipment, saving electricity and energy, and the monitoring detector adopts the instrument installation method.
AcrelAcrel-6000 series monitoring equipment is the top of the entire electrical fire monitoring system. It can connect multiple ARCM series detectors to form a complete set of electrical fire monitoring system with sound and light alarm function. It also displays alarm loops synchronously and its alarm information. Can save more than 12 months, backup uninterruptible power supply can ensure that the city power loss after continuous operation for more than 4 hours, the monitoring system is divided into wall-mounted, piano desktop and cabinet type 3, effective communication distance up to 1200 meters, multiple devices Equipment or other systems such as alarm and fire linkage systems, power monitoring systems, etc. can exchange data. And this series of monitoring equipment with self-test function, from the hardware, software, communication lines, power supply system in all aspects of self-test, in order to keep abreast of the system product running status, to ensure the reliability of the system operation.
5, software interface
This set of PC software Acrel-6000 electrical fire system. Mainly has the following function characteristic: The friendly man-machine contact surface, may gather the scene equipment the surplus electric current data and the temperature in real time and the time regularly, and has the warning prompt sound and light warning and so on the function. The customer can set the alarm temperature value and leakage current value according to actual needs. When the alarm fault is removed, it can be reset remotely. The system can record alarm events, dates, alarm values, over-line values, and generate reports.
1) Data Acquisition and Display
The on-site leakage fire monitoring detector uploads the collected data to this interface. The user can modify the name of the circuit, monitoring location, and monitoring area as required. When the actual measured value of the residual current is greater than the alarm setting, the system alarm status indicator will automatically flash, and the status of the alarm unit in the corresponding interface will change in color, facilitating the operator to check and handle the alarm.
2) Fault display
When the monitoring device detects a device fault, the status color of the fault unit on the monitoring main interface is changed, the specific information of the faulty unit is displayed, and a fault alarm sound is issued. Supports manual cancellation of fault alarms.
3) Fault and alarm records
With the event storage function, the alarm can record the time, type, parameter and alarm value of the fault and the alarm. According to the alarm record, the fault reason can be analyzed to provide the basis for eliminating the fault.
5 Conclusion
With the development of smart buildings and the widespread use of electricity, people have become more aware of security awareness. The installation of leakage current fire system in public buildings is an inevitable trend of intelligent construction. The electrical fire system is conducive to discovering hidden dangers and dealing with potential safety hazards in time. It is of great significance to prevent fires from occurring. Since this system was put into operation from the Eastern Airline Kunming Airport, more hidden dangers have been discovered and rectified, the work efficiency of the staff has been greatly improved, the daily work of the airport has been ensured to be carried out in a stable and orderly manner, and the travel safety of the broad masses of passengers has been ensured. The fire management provided the scientific basis.
references
[1]. Ren Cheng, Zhou Zhongzhong. Principles and Application Guide for Digital Meters for Electric Power Measurement [M]. Beijing. China Electric Power Press, 2007. 4
[2]. Wu Enyuan Zhouzhong Electric Fire Monitoring System Design and Application 2012. 8
About the Author:
Xu Shuang, female, undergraduate, Ankerui Electric Co., Ltd., the main research direction for medical power distribution design, mobile phone QQ
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