Arkori Qingqing Jiangsu Ankerui Electric Appliance Manufacturing Co., Ltd. Jiangyin , Jiangsu 214405 Abstract: This article briefly describes the composition principle of electrical fire monitoring system , and analyzes the design basis and related specifications of electrical fire monitoring system in application . Finally, through the example of the Ankerui residual current electrical fire monitoring system in the Lingang Bairun Times Square project, the realization of the function of the electrical fire monitoring system and its important significance are described. Keywords: electrical fire ; monitoring system; Acrel-6000/ B; Lingang Bairun Times Square 0 Foreword Electrical fire generally refers to the thermal energy released due to the faulty release of electrical lines, electrical equipment and power distribution equipment, such as high temperature, arc, spark and non-failure release of energy; such as the hot surface of electric heating appliances, with combustion conditions Fires caused by igniting a body or other flammable materials also include lightning caused by lightning and static electricity. Electrical fires mainly include the following four aspects: electric leakage fire, short-circuit fire, overload fire, and excessive contact resistance fire. * The Ministry of Fire Bureau's "China Fire Statistics Yearbook" shows that: In the 2010 fire accident, electrical fires took the first place, and the proportion of them took an upward trend, causing heavy losses. In fact, electrical fires have become the main disaster-causing factors for fire safety, not only because of the large number of times, but also because of large losses, and they have remained high for many years. 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 state departments have successively formulated or revised relevant standards and specifications and required the installation of electrical fire monitoring and alarm systems in buildings.   1 reference standard In recent years, the state has successively formulated or revised a number of relevant standards and regulations to strengthen the prevention of electrical fires in order to increase the intensity of prevention and control of electrical fires. There are: 1. It is GB50045-95 (2005 edition) " High-rise Civil Building Design Fire Prevention Code ", which provides in Article 9.5.1: The high-rise buildings in the fire risk, personnel intensive and other places should set up a leakage fire alarm system. 2. It is GB50016-2006 “Specifications for Fire Protection in Building Designâ€. It is stipulated in Clause 11.2.7 that the following places should be equipped with residual current action electrical fire monitoring system. These venues include various types of theaters , halls, warehouses , residential quarters , hospitals , shops , schools, and so on. 3. The relevant provisions of the national standard “Building electrical fire prevention requirements and detection methods†also clearly require that “the residual current protection device that automatically cuts off the power supply or alarm should be installed at the power supply inlet endâ€. 4. Electrical fire monitoring system products should meet: GB14287.1-2005 "Electrical fire monitoring equipment", GB14287.2-2005 "residual current electrical fire monitoring detector", GB14287.3-2005 "temperature-type electrical fire monitoring and detection Device 5. The installation and operation of electrical fire monitoring system shall meet GB13955-2005 "Installation and Operation of Residual Current Operation Protection Device" 6. The power supply of the electrical fire monitoring system shall meet the requirements of GB50052 "Design Specification for Power Supply and Distribution System" 7. Design of electrical fire monitoring system should meet (Provisional Regulations) requirements "design of electrical fire monitoring system" of 2 system 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 shall include: electrical fire monitoring equipment, residual current electrical fire Monitoring detectors and temperature-detection type electrical fire monitoring detectors are composed of the three most basic product categories. 1. 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 sensor Made up of. 2. The residual current type electrical fire monitoring system adopts a hierarchical distributed structure, which is composed of station management layer, network communication layer and field device layer . All electrical fire monitoring probes are connected to the communication server through a shielded twisted pair RS485 interface, using a MODBUS communication protocol bus type connection, and then enter the industrial switch through the Category 5 TCP/TP protocol, and then reach the monitoring host through the optical cable. a) The field device layer is mainly connected to various types of instruments and protective devices used for the collection and measurement of electrical parameters in the network, and it is also a necessary basic element for constructing the monitoring system. It not only shoulders the burden of collecting data, but it is also a terminal component that executes background control commands. b) The communication control layer is mainly composed of communication server, interface conversion device and bus network. This layer is a 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 to open / close operation commands; microprocessor protection device is mainly to ensure the normal operation of the host computer to avoid interference or damage caused by unstable signals in the network; interface conversion device It is due to differences in the communication interface between the field instrument or other series of devices and the host computer. It is necessary to perform the conversion before the data exchange. c) Management The monitoring and control layer is for the management personnel of the monitoring network, and this layer directly faces the users. 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, 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 automatically calculates and processes the data. It reflects 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. 3 system features and working principle The characteristics of the electrical fire monitoring system are that the residual current monitoring is an early warning system. Unlike traditional fire automatic alarm systems, early warning of electrical fire monitoring systems is to avoid losses, while traditional fire automatic alarm systems are used to reduce losses. Therefore, this means that no matter whether it is a new or reconstructed project, especially a unit that has already installed an automatic fire alarm system, it still needs to install the root cause of the electrical fire monitoring system. The electrical fire monitoring system measures the two physical quantities of residual current and temperature. Residual current measurement is based on Kirchhoff's current law: At the same time, the vector of current flowing into and out of a node in the circuit is zero. Taking the TN-S system as an example, the A/B/C/N is passed through the residual current transformer at the same time. When the system is not leaking, the current vector flowing into and out of the residual current transformer is zero, and at this time, the residual current The secondary current induced by the transformer is also 0; when a leakage occurs on a relatively large ground, the current vector at the time of flowing into and out of the residual current transformer is no longer zero, and its magnitude is equal to the current flowing from the ground, ie the leakage current. The leakage signal is transmitted to the electrical fire detector through the secondary wiring of the residual current transformer, and is subjected to operation amplification, A/D conversion and then sent to the CPU. After a series of algorithms, the amplitude of the change is analyzed, judged, and The alarm setting value is compared. If the setting value is exceeded, an audible and visual alarm signal is sent and sent to the back-end electrical fire monitoring equipment. The temperature measurement uses a temperature sensor, which is generally measured using a Pt100 sensor. This type of temperature sensor has a stable temperature measurement range and a large measuring range. It is suitable for on-site monitoring of cable temperature and ambient temperature. When the temperature changes, the resistance of Pt100 changes with the same proportion. The resistance signal is transmitted to the electrical fire detector. After a series of signal conversion and calculation, the final result is compared with the temperature alarm setting value. If the value exceeds the fixed value, An audible and visual alarm signal is sent and sent to the back-end electrical fire monitoring equipment. 4 System Design Considerations and Methods 4.1 Electrical fire monitoring systems mainly monitor the residual current and temperature objects, and should pay attention to the basic points in the design (1) Residual current Since the principle of residual current monitoring adopts Kirchhoff's current law, there is a certain requirement for the form of the applied low-voltage power distribution system. At present, low-voltage power distribution systems that can use residual current transformers are: TT systems, IT systems, TN-S systems, and cannot be used in TN-C systems. For users who will design and install an electrical fire monitoring system, whether it is a new project or an old one, it is necessary to first investigate and verify what the system grounding form of the user's low-voltage power distribution system is. Otherwise, design and install the point of the residual current transformer. Testing is simply not possible. With regard to the AC220V single-phase power supply system, the residual current transformer may only cover two L/N power lines, but it is required that the neutral line N is not allowed to be grounded thereafter. For the AC380V three-phase power supply system, due to the use of three-phase three-wire system, three-phase four-wire system, three-phase five-wire system, etc., according to the specific circumstances of the residual current transformer will be at the same time jacketed A / B / C three-phase power line, Or cover the A/B/C/N line at the same time. Similarly, it is required that the neutral line N is not allowed to be grounded after that and the protection line PE must not pass through the transformer. When the system is grounded in the form of a TN-C type industrial automation network, it must be converted to a TN-S type, TN-CS type, or a local TT type system before the residual current detection device can be installed. (2) About temperature The temperature measurement has nothing to do with the form of system grounding. It mainly considers the temperature of key parts in low-voltage power distribution equipment, including cables, and is generally applied in the secondary protection circuit. The temperature probe Pt100 can adopt the contact arrangement method. When the detected object is an insulator, the temperature sensor of the detector should be directly set on the surface of the object to be detected. When the detected object is a change in the internal temperature of the distribution cabinet, a non-contact arrangement can be used, close to the heat-generating components. 4 .2 Point allocation in system design According to the provisions of the national standard GB13955-2005 “Installation and Operation of Residual Current Operation Protection Device†4.4, concerning graded protection, when installing the residual current fire monitoring device, the steps of point allocation principle are: (1) Study and analyze the relevant drawings of the controlled low-voltage AC380V/220V distribution line, investigate and verify the distribution of the building electrical, and determine the location of the distribution equipment (such as distribution cabinets, boxes, trays, cables and other important equipment). Each monitoring detector is assigned to the corresponding distribution equipment to determine the number of detectors and avoid resetting waste. (2) Determine graded protection. In order to reduce the scope of power outage caused by personal accidents and ground faults when the power is cut off, three-level (or two-level) residual current protection devices of different capacities are usually installed at different locations of the power supply line to form a graded protection. According to the power load and the line conditions, it is generally divided into two or three levels of protection, which is suitable for the protection of the first and second levels in urban and rural areas. Among them, the important lines should include security, fire protection, emergency power supply, channel lighting lines and important places that do not allow blackouts. (3) In the secondary protection, all switches must be installed with a residual current fire monitoring detector, that is, both the power supply end (first-level protection) and the branch head end (second-level protection, also called end protection) of the line. Install residual current detectors and access electrical fire monitoring systems for fire monitoring applications only*. (4) In the three-level protection, the residual current detector and the action protection device shall be installed at the third-level (ie end protection) switch, but the electrical fire monitoring system is not connected to prevent electric shock. (5) Temperature detection is based on the basic principle of heat generation in abnormal distribution equipment . 1) transformer low voltage side outlet terminal, transformer body temperature (wind temperature, oil temperature, water temperature) test point, load switch contacts. 2) Access points of the power distribution cabinets (boxes), contact points of automatic switches (circuit breakers, knife switches), concentrated current conductors, and cable connection points. 3) Master contact, knife switch contacts. 4) Compensation capacitor terminals and transfer switch contacts. (6) According to the total number of installation points, and then select the appropriate wall, vertical or Qintai. 5 configuration of system parameters 5 .1 Alarm value setting range According to the provisions of the national standard GB14287.2-2005, the alarm value of the residual current type electrical fire monitoring detector is set in the range of 20~1000mA. According to this requirement, the residual current operating value at the total power supply line is generally set at 400~800mA, and the residual current operating value at the power branch line is set at 100~400mA. Generally, the residual current type electric fire monitoring and detection is set at the actual site. The alarm value of the device shall not be less than 2 times the maximum value of the leakage current during normal operation of the protected electrical circuit and equipment, and shall not be greater than 1000 mA . Electrical fire detectors' alarm settings should take into account the normal leakage currents of the distribution system and electrical equipment. About 5.2 temperature alarm set reference cable, the cable in accordance with the provisions of the relevant temperature "power cable design" (1) High-temperature places above 60 °C should be subjected to high temperature, duration, and insulation type requirements. Heat-resistant cables such as heat-resistant polyvinyl chloride, cross-linked polyethylene, or ethylene-propylene rubber insulation should be selected. Minerals at temperatures above 100 °C should be minerals. Insulated cable. High-temperature places should not use ordinary PVC insulated cables. (2) The ambient temperature of the cable that allows constant current carrying capacity shall be determined according to the average of the meteorological temperatures in the area of ​​use for many years, and shall comply with the regulations. When indoor cable trenches are laid, the ambient temperature is the average daily maximum temperature of the hottest month plus 5 °C . (3) The temperature rise of the cable is related to laying and heat dissipation conditions. 6 system design examples “Bairun Times†is located in the Lingang New City core business district on the East Sea of ​​Pudong, Shanghai, adjacent to Shanghai's most prestigious Disthui Lake Tourism and Recreational Resort. It is a hotel-style office and leisure shopping built by Baiyexin Group for 3 years. , catering and entertainment as one of the high-quality commercial complex building; project covers an area of ​​over 10,000 square meters, a total construction area of ​​nearly 50,000 square meters, the overall functional planning is divided into commercial and office parts, podium 22.5 meters high, a ground floor The total floor area of ​​the building to the fourth floor is approximately 35,000 square meters. The function is positioned as a shopping center. The second floor area is approximately 8,000 square meters. The function is parking and auxiliary rooms. The planned parking space is 180 vehicles. The main building is 62 meters high and the fifth floor to the ninth floor. The total area of ​​nearly 8,000 square meters, the functional orientation of the hotel-style office. The electric fire monitoring system at Lingang Bairun Times Square consists of an electrical fire monitoring device Acrel-6000 /B, a leakage fire detector ARCM 3 00-J 1 , and a leakage current transformer AKH-0.66L. Acrel-6000 electrical fire monitoring system is an independent research and development by the company to receive the residual current electrical fire detectors and other field equipment signals to achieve the alarm, monitoring, control and management of the protected electrical circuit running on the computer's industrial level Hardware/software system. This system is applied to fire control centers in large shopping malls, living quarters, production bases, office buildings, shopping malls and hotels, and remotely measures, remotely adjusts, remotely controls, and remotely detects the detectors scattered in buildings to facilitate monitoring and management. The system uses a standard Modbus field bus to connect detectors with communication functions. When the detected parameters in the field protection circuit exceed the alarm setting value, it can send alarm signals, control signals, can indicate alarm locations and save alarms. information. There are 101 ARCM 300 -J 1 residual current type fire detectors on the site of Lingang Bairun Times Square , installed at the entrance of the floor distribution box . Fire detector using field mode bus connected to the control center of the dissipation Acrel-6000 / B Wall electrical fire control system. This system has the advantages of convenient installation and transportation, high cost performance, and easy maintenance. The main technical parameters 1. Power supply : 1 rated working voltage AC220V (-15% ~ +10%) 2 Standby power supply: When the main power supply is undervoltage or power failure, maintain the monitoring equipment working time ≥ 4 hours 2. Work system : 24-hour work 3. Communication method : RS485 bus communication, Modbus-RTU communication protocol, transmission distance 1km, can extend communication transmission distance through repeater 4. Monitoring capacity : 1 Monitoring equipment can monitor up to 200 monitoring units (detectors) 2 can be connected with ARCM series monitoring detector 5. Monitoring alarm items : 1 Residual current fault (leakage): Fault cell attributes (position, type) 2 Temperature alarm (over temperature): Fault cell attributes (part, type) 3 Current fault (overcurrent): Fault cell attributes (part, type) Monitoring alarm response time: ≤30s Monitoring alarm sound pressure level (A weighting): ≥70dB/1m Monitoring alarm light display: red LED indicator, red light alarm signal should be maintained until manual reset Monitoring alarm sound signal: Can be eliminated manually, when it is alarm signal input again, it can start again 6. Fault alarm items : 1 An open circuit or short circuit occurred in the communication cable between the monitoring equipment and the detector 2 Monitoring equipment main power supply undervoltage or power failure 3 An open circuit or short circuit occurred in the connection between the battery charger and the battery Fault alarm response time: ≤100s Monitoring alarm sound pressure level (A weighting): ≥70dB/1m Monitoring alarm light display: yellow LED indicator, yellow light alarm signal should be maintained until troubleshooting Fault alarm sound signal: can be eliminated manually, when the alarm signal input again, can start again During faults, normal operation of non-failed circuits is not affected 7. Control output : Alarm control output: 1 set of normally open passive contacts, capacity: AC250V 3A or DC30V 3A 8. Self-inspection project : 1 Indicator check: alarm, fault, operation, main power, standby power indicator 2 display check 3 audio device inspection Self-check time ≤60s 9. Event record : 1 Record content: record type, occurrence time, detector number, area, fault description, no less than 20,000 records can be stored 2 record query: according to the record of the date, type and other conditions 10. Operational rating : 1 daily shift: real-time status monitoring, event record query 2 monitoring operation level: real-time status monitoring, event record query, remote reset of the detector, device self-test 3 System management level: real-time status monitoring, event record query, remote reset of detector, device self-check, system parameter query of monitoring equipment, individual detection of each module of monitoring equipment, operator addition and deletion 11. Use environmental conditions : 1 Workplace: fire control room, manned power distribution (distribution room), on-site walls 2 working environment temperature: 0 °C ~ 40 °C 3 working environment relative humidity: 5% to 95% RH 4 Altitude: ≤ 2500m basic skills 1. Monitoring alarm function: The monitoring equipment can receive the leakage and temperature information of multiple detectors. When the alarm sounds, an audible and visual alarm signal is emitted. At the same time, the red “alarm†indicator light on the equipment is on. The display indicates the alarm location and the type of alarm. The alarm time is recorded and the sound and light alarm is maintained. Until the display resets the detector remotely. The audible alarm signal can also be manually cancelled using the display “Mute†button. 2. Fault alarm function Communication failure alarm: When a communication failure occurs between the monitoring device and any connected detector, the corresponding detector in the monitoring screen displays a fault prompt, and the yellow “fault†indicator light on the device is on, and a fault alarm sound is emitted. . Power failure alarm: When the main power supply or standby power supply fails, the monitoring device also emits an audible and visual alarm signal and displays the fault information. You can enter the corresponding interface to view detailed information and cancel the alarm sound. 3. Self-test function Check if all the status indicators, display screens and speakers in the device are normal. 4 alarm record storage query function When leakage, over temperature alarm, or communication or power failure occurs, the alarm location, fault information, alarm time, and other information are stored in the database. When the alarm is removed and the fault is eliminated, it is also recorded. Historical data provides a variety of convenient and fast methods for searching. 5. Power function When the main power supply has a power failure or undervoltage, the monitoring device can automatically switch to the standby power supply. When the main power supply resumes normal power supply, it automatically switches back to the main power supply, ensuring continuous and smooth operation of the monitoring device during the switchover process. 6. The detector control function By monitoring the software operation, remote reset control can be performed on all detectors connected to the device. 7. Authority control function In order to ensure the safe operation of the monitoring system, the monitoring device software operating authority is divided into three levels, and different levels of operators have different operating rights. System network structure 1) Station control management Station management The management personnel of the electrical fire monitoring system are the direct windows of human-computer interaction and the top part of the system. Mainly by the system software and necessary hardware devices, such as touch screen , UPS power supply and other components. The monitoring system software calculates, analyzes, and processes various types of data on the site, and responds to the on-site operations by means of graphics, digital display, sound, and indicator lights. Monitoring host: used for data acquisition, processing and data forwarding. Provides data interfaces within or outside the system for system management, maintenance, and analysis. UPS: Ensure the normal power supply of the computer monitoring system. When the power supply problem occurs in the entire system, ensure the normal operation of the station control and management equipment. Background monitoring equipment is located in the basement of the control center. Communication medium: The system mainly adopts shielded twisted pair, uses RS485 interface, MODBUS communication protocol to achieve real-time communication between the field device and the host computer. 3) Field device layer The field device layer is a data acquisition terminal, mainly ARCM 3 00-J 1 residual electrical fire monitoring detector. The ARCM 3 00 residual current type electric fire monitoring detector is designed for TT and TN systems up to 0.4kV. It monitors and controls fire hazard parameters such as residual current, conductor temperature, overcurrent and overvoltage in the distribution circuit. management, so as to prevent electrical fires, and enables real-time monitoring of multiple power parameters, provide accurate data for the energy management. Products using advanced microcontroller technology, high degree of integration, compact size, easy installation, set intelligent, digital, network in one, is the building electrical fire prevention and control, system insulation, such as the estimated aging of the ideal choice. The product complies with the standard requirements of GB14287.2-2005 "Electrical fire monitoring system Part 2: Residual current electrical fire monitoring detector". The distributed I/O controller connected to the fieldbus forms a data acquisition terminal and uploads the collected data to the data center. The measuring probes are responsible for the most basic data acquisition tasks. The data they monitor must be complete, accurate and transmitted to the monitoring host in real time. It is convenient for operating personnel to monitor the status of field equipment operation, fault alarms, etc. to effectively prevent the occurrence of fire accidents. The system has been operating well since it was put into operation and has played an important role in preventing electrical fires. It has gained customers' recognition and trust in products and companies. references [1]. Ren Chengcheng, Zhou Zhong. Principles and Application Guide for Digital Meters for Electric Power Measurement [M]. Beijing. China Electric Power Press, 2007. 4 [2].Zhou Zhong. Application of Power Meters in Energy Metering of Large-scale Public Buildings [J]. Modern Building Electronics 2010. 6 Oxygen Sensor For Ferrari,Ferrari Oxygen Sensor,Ferrari O2 Sensor,Ferrari Auto Sensor RUIAN XIANGTAI AUTOMOTIVE PARTS CO ., LTD , https://www.raxiangtais.com
2) Network communication layer 