Application of Acrel-6000 Electrical Fire Monitoring System in Area B of Guiyang International Financial Center

Xu Shuang

Ankerui Electric Co., Ltd. Shanghai Jiading 201801

Abstract: Building electrical fires account for a large proportion of building fires, and there are many causes of fire, including short circuit, overheating, electric leakage, lightning strikes and electrical faults, and the fire hazard is also large. Therefore, fires caused by various reasons should be effectively controlled. At present, protection measures such as short circuit, overheating and lightning strike are becoming more and more mature, and due to the prevalence of normal leakage current, leakage often does not attract enough attention, resulting in fire. Obviously, it is necessary to use the leakage current detection to give an early warning and alarm system for fire. This paper introduces the application of Ankerui Acrel-6000 electrical fire monitoring system in 1-4# building of Zone B of Guiyang International Center, analyzes relevant national standards and design specifications, and outlines the specific structure of electrical fire monitoring system in electrical fire prevention. And its superiority.

Keywords: public buildings; electrical fires; Ankerui; electric leakage fire; Guiyang International Financial Center; Acrel-6000

0 Preface

With the continuous improvement of the living standards of our people, the power consumption has been increasing, but the electrical fires have also increased dramatically, which has caused huge losses to the national economy and people's lives and property. According to the "China Fire Statistical Yearbook" statistics, electric fires rank first in recent years, and the proportion is 30%, and it is rising year by year, causing heavy losses. In fact, electrical fires have become the main cause of fire safety, not only in many times, but also in large losses, and have remained high for many years.

The main causes of electrical fires in public buildings are as follows:

0.1 The conductors in the building have been in disrepair for a long time, and the insulation layer is aging and damaged.

0.2 The installation and installation of the conductors in the building are not standardized. If the conductors are not protected by pipelines, they are buried directly in the wall or placed on the components.

0.3 When public places such as entertainment venues are in the second renovation, the wires are laid in disorder, causing hidden fire hazards.

0.4 Wire construction quality is rough, cut corners, and the use of steel pipe threading is the insulation of the wire inside the steel pipe.

0.5 The line is affected by natural conditions, such as the humidity of the air causing the insulation level of the wire to drop.

In view of the above aspects, Ankerui Electric Co., Ltd. based on its self-developed ARCM series electrical fire monitoring detectors, through the integration of RS485 bus technology and terminal microcomputer software display technology, developed Acrylic Acrel-6000 /B electrical fire monitoring system. The background of the system displays the data of each detection point, and also provides functions such as over-limit sound and light alarm and humanized interface. The system realizes 24-hour unattended real-time monitoring of the power distribution system, reduces labor costs, and improves the elimination efficiency of electrical fire hazards.

This paper briefly introduces the practical application of the Acry-6000 electrical fire system and its practical significance in the application of the electrical fire system in the 1-4# building of the B-zone of Guiyang International Financial Center.

1 Project Overview

Guiyang International Financial Center Area B is located at the intersection of Lincheng East Road and Changling North Road in Guanshanhu District. The land area is 106821.7 square meters, the total construction area is 94831.59 square meters, and the building area is 45006.48 square meters (commercial 43697.12 square meters). 998.70 square meters of equipment room, 256.72 square meters of property management room, 54.13 square meters of fire control room, no building capacity: 49,825.11 square meters (49314.96 square meters of garage, 540.14 square meters of overhead floor), 965 underground parking spaces planned 2 floors underground, above ground level for greening; underground building area: 94831.59 square meters, building density: 44%, floor area ratio: 0.46, public building supporting facilities: 1309.55 square meters.

The project has a total of four mainframes in the 1-4# building of Zone B of Guiyang International Financial Center. .

Our company selects residual current type electric fire detector ARCM300L-J1, residual current type electric fire monitoring equipment and electric fire monitoring system Acrel-6000/Q for the project. The system has the functions of centralized scheduling, control, protection, monitoring, display, etc. It has the advantages of intelligent management, control, protection, analysis and recording of electricity, which can greatly reduce the incidence of electrical fires in applications.

A wall-mounted electrical fire monitoring host is installed in the fire control room, and the data of the administrative office building, the canteen, and the research and development center are uploaded to the fire control room background monitoring host.

In view of the characteristics of this project, in order to prevent electrical fires caused by ground faults, combined with the importance of this project, all lighting and power distribution systems of this project are equipped with leakage fire alarm system. The system mainly includes a system host, a field monitor, and a data centralized controller. The leakage fire alarm host is set in the fire control room. The system installs a leakage fire detector on the incoming line of the distribution box of each floor, and monitors the leakage current at the place. When the leakage current of the distribution circuit is detected to be greater than 300 mA and the working current exceeds the alarm value set by the time limit, the system issues The sound and light alarm signal accurately reports the address of the fault point, monitors the change of the fault point, displays its status, and only gives an alarm signal to the equipment power circuit, without cutting off its power supply.

2 reference standard

In view of the fire in public buildings, it is easy to cause loss of life and property. In order to increase the intensity of electrical fire monitoring and prevention, in recent years, the state has successively formulated or revised a number of relevant standards and norms. The relevant standard specifications have put forward specific requirements for the electrical fire monitoring system. The design standards for the design of the Acrylic-Accor-6000 electrical fire system selected in this project are as follows:

2.1 GB50045-95 (2005 edition) "Code for Fire Protection Design of High-rise Civil Buildings", which stipulates in Article 9.5.1 that a fire alarm system should be installed in places with high fire risk and dense personnel in high-rise buildings.

2.2 The relevant provisions of the national standard "Building electrical fire prevention requirements and testing methods" also clearly require that "the residual current action protector that automatically cuts off the power or alarm should be set at the power incoming end."

2.3 The products of the electrical fire monitoring system shall meet: GB14287.1-2014 "Electrical fire monitoring equipment", GB14287.2-2014 "Residual current type electric fire monitoring detector", GB14287.3-2014 "Temperature type electric fire monitoring" detector"

2.4 The installation and operation of the electrical fire monitoring system shall meet the requirements of GB13955-2005 "Installation and operation of residual current action protection device"

2.5 The power supply of the electrical fire monitoring system shall meet the requirements of GB50052 "Design Specifications for Power Supply and Distribution Systems"

2.6 The design of the electrical fire monitoring system shall meet the requirements of the Design Method of Electrical Fire Monitoring System (Interim Provisions)

3. System architecture and design

Electrical fire monitoring system topology

3.1 Station management

The management of the station control management system for the electrical fire monitoring system is the direct window of human-computer interaction and the uppermost part of the system. The Encore Electric Fire Monitoring System mainframe fully takes into account the user's operating habits and continuous and stable operation, with reference to the corresponding national standards and specifications. The host computer is mainly composed of monitoring software, touch screen, UPS power supply, printer and other equipment. The various types of data information on the site are calculated, analyzed, and processed, and reacted to the terminal management personnel in the form of graphics, digital display, sound, and indicator lights. Enables managers to grasp system dynamics in real time, and realizes functions such as fault information can be traced and information can be exported.

In view of the instrument point and the amount of data in this project, the Acrylic-Acrel-6000/B host is now configured for the project. The specific parameters of this host are described below.

3.2 Network communication layer

All instruments in this project must be connected in strict accordance with the hand, and all communication buses must be laid along the weak bridge. The instruments of this project are distributed in the power distribution cabinets on the floor.

The data bus of this project is designed as two buses. The independent bus facilitates the maintenance of the later system. When a leakage current alarm occurs, the fault circuit can be quickly located according to the checklist provided by us in the later stage to quickly eliminate the fault.

The on-site electrical fire detectors are connected by hand in a twisted pair (ZR-RVSP2*1.0), and the number of instruments per bus is less than 30.

3.3 Field device layer

In this project, the Ankerui rail-type electrical fire detector ARCM300L-J1 is installed for the incoming circuit of the floor distribution box. The leakage current of the distribution circuit is monitored in real time by the rail-type electrical fire detector to display the entire power distribution system. Working status.

The ARCM series residual current type electrical fire monitoring detector is designed for TT and TN systems below 0.4kV. It monitors and manages the fire hazard parameters such as residual current and wire temperature of the distribution circuit to prevent electrical fires. And real-time monitoring of multiple power parameters to provide accurate data for energy management. The product adopts advanced microcontroller technology, with high integration, small size, convenient installation, intelligent, digital and networked. It is an ideal choice for building electrical fire prevention monitoring and system insulation aging prediction. The product complies with the standard requirements of GB14287.2-2014 "Electrical Fire Monitoring System Part 2: Residual Current Electrical Fire Monitoring Detector".

4 system characteristics and working principle

In view of the scale of the project, the actual situation of the project electrical fire detection points. Whether in the terminal residual current detector or the background host is designed according to the actual situation of the project.

4.1 The system characteristics of this project can be summarized as follows:

4.1.1 The terminal detector adopts the rail type electrical fire detector, which is convenient for installation, cost saving and convenient for later maintenance.

4.1.2 RS485 bus connection is convenient and operability is strong. When the bus is routed, it is a weak bridge, which is not affected by strong electricity, ensuring stable communication of the entire system.

4.1.3 Taking into account the amount of instrument data in this project, customer requirements. The host of this project is wall-mounted. The wall-mounted host has a simple interface and is easy to operate. It is suitable for the distribution room environment and customer related operation requirements in this project.

4.2 Working principle of electrical fire system

4.2.1 The residual current measurement is based on Kirchhoff's current law: at the same time, the sum of the current vectors flowing into and out of a node in the circuit is zero. Taking the TN-S system as an example, A/B/C/N is simultaneously passed through the residual current transformer. When there is no leakage in the system, the current vector sum of the residual current transformer flowing into and out is zero. At this time, the residual current The secondary current induced by the transformer is also 0; when a relatively large earth leakage occurs, the current vector sum of the current transformer flowing into and out of the residual current is no longer zero, and its magnitude is equal to the current flowing from the earth, that is, the leakage current. The leakage signal is transmitted to the electrical fire detector through the secondary wiring of the residual current transformer, and is sent to the CPU after operation amplification, A/D conversion, and after a series of algorithms, the amplitude of the change is analyzed and judged, and The alarm set value is compared. If the set value is exceeded, an audible and visual alarm signal is sent and sent to the background electrical fire monitoring device.

4.2.2 The terminal detector is responsible for monitoring the residual current value of each loop and transmitting the data of the residual current value to the system host. The terminal detector is also responsible for the real-time display of the residual current value of the monitoring circuit, and can set the limit value. When the residual current value exceeds the limit, it can emit an audible and visual alarm to remind the management personnel to maintain and rectify in time.

4.2.3 The instrument transmits data to the system host through RS485 bus. The system host reflects the running status of the whole system through graphs, reports, event records and other forms.

5 System design considerations and methods

5.1 Electrical fire monitoring system mainly monitors two types of objects, residual current and temperature, and should pay attention to the basic points in design.

5.1.1 About residual current

Since the principle of residual current monitoring uses Kirchhoff's current law, there are certain requirements for the form of the low-voltage power distribution system to be applied. At present, low-voltage power distribution systems that can apply residual current transformers are: TT system, IT system, TN-S system, and cannot be used in TN-C system. For users who will design and install an electrical fire monitoring system, whether it is a new project or an old engineering project, first check the system grounding form of the user's low-voltage power distribution system. Otherwise, design and install the residual current transformer. Detection is simply not possible.

Regarding the AC220V single-phase power supply system, the residual current transformer only needs to cover the L/N power lines, but the neutral line N is not allowed to be grounded again. For the AC380V three-phase power supply system, due to the three-phase three-wire system, three-phase four-wire system, three-phase five-wire system, etc., the residual current transformer is simultaneously sheathed to the A/B/C three-phase power line according to the specific situation. Or cover the A/B/C/N line at the same time. Similarly, the neutral line N is not allowed to be grounded again, and the protection line PE must not pass through the transformer.

When the system grounding type is TN-C type, the industrial automation network must be converted into a TN-S type, TN-CS type or partial TT type system before the residual current detecting device can be installed.

5.1.2 About temperature

Temperature measurement has nothing to do with the form of system grounding. It mainly considers the temperature of key parts of low-voltage power distribution equipment including cables, and is generally applied in secondary protection lines. The temperature probe Pt100 can adopt the contact arrangement method. When the object to be detected is an insulator, the temperature sensor of the detector should be directly disposed on the surface of the object to be detected. When the object to be tested is the temperature change inside the power distribution cabinet, a non-contact arrangement can be adopted, which is close to the heat generating component.

5.2 Point allocation in system design

According to the national standard GB13955-2005 "Residual current action protection device installation and operation" in the provisions of 4.4 on the classification protection, when installing the residual current fire monitoring device, the steps of the point allocation principle are:

5.2.1 Study and analyze the relevant drawings of the controlled low-voltage AC380V distribution line, investigate and verify the distribution of building electrical, and determine the location of the distribution equipment (such as power distribution cabinets, boxes, disks, cables, etc.), The monitoring detectors are assigned to the corresponding power distribution equipment to determine the number of detectors and avoid resetting waste.

5.2.2 Determine the hierarchical protection. In order to reduce the range of power failure caused by the occurrence of personal electric shock accidents and ground faults, three-stage (or two-stage) residual current protection devices of different capacities are usually installed at different locations of the power supply line to form hierarchical protection. According to the power load and line conditions, it is generally divided into two or three levels of protection, suitable for urban and rural first and second level protection.

Among them, important routes should include security, fire, emergency power, channel lighting and important places that do not allow power outages.

5.2.3 In the secondary protection, all the switches shall be equipped with a residual current fire monitoring detector, that is, at the power supply end of the line (first level protection) and the branch head end (second stage also called end protection). Install the residual current detector and connect it to the electrical fire monitoring system for fire monitoring and alarm.

5.2.4 Temperature detection is based on the basic principle that heat is generated when the power distribution equipment is abnormal.

1) Transformer low-voltage side outlet terminal, transformer body temperature (wind temperature, oil temperature, water temperature) test point, load switch contact.

2) Incoming and outgoing busbar contacts, automatic switch (circuit breaker, knife switch) contacts, large current conductor concentrated parts, and cable docking points of each power distribution cabinet (box).

3) The main joint of the female joint cabinet and the switch contacts of the knife.

4) Compensation capacitor terminal and transfer switch contact.

5.2.5 According to the total number of points installed, select the corresponding wall hanging.

6 System parameter configuration

6.1 Alarm value setting range

The residual current alarm value of the field instrument in this project is set at 600mA. The setting of the residual current value is detailed in the relevant national standards.

According to the national standard GB14287.2-2014, the alarm value of the residual current type electrical fire monitoring detector is set between 20~1000mA. According to this requirement, the residual current action value at the power supply main line is generally set to 400~800mA, and the residual current action value on the power branch line is set to 100~400mA. Generally, the residual current type electrical fire monitoring 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 not more than 1000 mA. The alarm setting value of the electrical fire detector should take into account the normal leakage current of the power distribution system and the electrical equipment.

6.2 Refer to the cable temperature rise alarm setting reference, according to the "Power Cable Design Specification" for cable temperature requirements

6.2.1 High temperature places above 60 °C should be selected according to the requirements of high temperature and duration and insulation type. Heat-resistant PVC, XLPE or Ethylene-propylene rubber insulation and other heat-resistant cables should be used. Insulated cable. It is not advisable to use ordinary PVC insulated cables in high temperature places.

6.2.2 The ambient temperature of the continuous allowable current carrying capacity of the cable shall be determined according to the multi-year average of the meteorological temperature of the area of ​​use and shall comply with the regulations. When the indoor cable trench is laid, the ambient temperature is the average daily temperature of the hottest month of the site plus 5 °C.

6.2.3 The temperature rise of the cable is related to the laying and heat dissipation conditions.

7 main equipment parameters

The 1-4# building in Zone B of Guiyang International Financial Center consists of the electrical fire monitoring device Acrel-6000/Q, the leakage fire detector ARCM300L-J1, and the leakage current transformer AKH-0.66L.

7.1 main technical parameters

7.1.1 Power supply:

1 rated working voltage AC220V (-15% ~ +10%)

2 Standby power supply: When the main power supply is under voltage or power failure, maintain the monitoring equipment working time ≥ 4 hours

7.1.2 Working system:

24-hour work schedule

7.1.3 Communication method:

RS485 bus communication, Modbus-RTU communication protocol, transmission distance 1.2km, can extend communication transmission distance through repeater

7.1.4 Monitoring capacity:

1 Monitoring equipment can monitor 1024 (customized) monitoring units (detectors)

2 can be connected with ARCM series monitoring detector

7.1.5 Monitoring alarm items:

1 Residual current fault (leakage): fault unit attribute (part, type)

2 Temperature alarm (over temperature): Fault unit attribute (part, type)

3 Current fault (overcurrent): Fault unit attribute (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 manually eliminated, can be started again when there is alarm signal input again

7.1.6 Fault alarm item:

1 The communication cable between the monitoring device and the detector is open or shorted.

2 Monitoring equipment main power supply undervoltage or power failure

3 The cable between the charger that charges the battery and the battery is broken or shorted.

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 kept until troubleshooting

Fault alarm sound signal: can be manually eliminated, can be started again when there is an alarm signal input again

The normal operation of the non-faulty loop is not affected during the fault

7.1.7 Control output:

Alarm control output: 1 set of normally open passive contacts, capacity: AC250V 3A or DC30V 3A

7.1.8 Self-test items:

1 Indicator check: alarm, fault, operation, main power, standby power indicator

2 display check

3 audio device inspection

Self-test time ≤60s

7.1.9 Event Record:

1 Record content: record type, time of occurrence, detector number, area, fault description, can store no less than 20,000 records

2 record query: query according to the date, type and other conditions of the record

7.1.10 Operational Rating:

1 Daily duty class: real-time status monitoring, event record query

2 Monitoring operation level: real-time status monitoring, event record query, detector remote reset, device self-test

3 System management level: real-time status monitoring, event record query, detector remote reset, device self-test, monitoring device system parameter query, monitoring device module detection, operator addition and deletion

7.1.11 Environmental conditions for use:

1 Workplace: Fire control room, manned substation (distribution room), wall on room where someone is on duty

2 Working environment temperature: 0 ° C ~ 40 ° C

3 Working environment relative humidity: 5% ~ 95% RH

4 Altitude: ≤2500m

7.2 basic functions

7.2.1 Monitoring alarm function:

The monitoring equipment can receive the leakage and temperature information of multiple detectors, and emit an audible and visual alarm signal when the alarm occurs. At the same time, the red “alarm” indicator on the device lights up, the display indicates the alarm location and alarm type, and the alarm time is recorded. The sound and light alarm is always maintained. Until the display is reset by pressing the display "Reset" button. The audible alarm signal can also be manually removed using the display "Muffler" button.

7.2.2 Fault alarm function

Communication failure alarm: When a communication failure occurs between the monitoring device and any of the connected detectors, the corresponding detector in the monitoring screen displays a fault indication, and the yellow “fault” indicator on the device lights up, and a fault alarm sound is emitted. .

Power failure alarm: When the main power or backup power 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 the detailed information and release the alarm sound.

7.2.3 Self-test function

Check that all status indicators, display, and speakers in the device are normal.

7.2.4 Alarm record storage query function

When leakage, over-temperature alarm or communication or power failure occurs, the alarm part, fault information, alarm time and other information are stored in the database. When the alarm is cancelled or the fault is eliminated, the same is recorded. Historical data provides a variety of convenient and fast ways to query.

7.2.5 Power function

When the main power supply has a power failure, undervoltage, etc., the monitoring equipment can automatically switch to the standby power supply. When the main power supply returns to normal power supply, it automatically switches back to the main power supply, ensuring continuous and smooth operation of the monitoring equipment during the switching process.

7.2.6 Detector control function

Remote monitoring of all detectors connected to the unit is possible through monitoring software operation.

7.2.7 Privilege Control Function

In order to ensure the safe operation of the monitoring system, the monitoring device software operation authority is divided into three levels, and different levels of operators have different operation rights.

Conclusion

In summary, the leakage fire alarm system can accurately detect the faults and abnormal conditions of the electrical circuit, can find the fire hazard of the electrical fire, and promptly alert the personnel to eliminate these hidden dangers. From the perspective of building safety, the design of building leakage fire alarm system is very important. In the long run, the leakage fire alarm system can be used as a subsystem in the automatic fire alarm system, thus realizing the optimal combination of strong and weak electricity, and constitutes a complete automatic fire alarm system.

references

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[2]. Shenyang Fire Research Institute. GB 50116 - 2013 Design Specification for Automatic Fire Alarm System [S]. Beijing: China Planning Press, 2014

[3]. Department of Fire Services. Fire Safety Technology Practice [M]. Beijing: Mechanical Industry Press, 2014.