【 Weak current College 】 intelligent building weak electricity system distribution model

Summary: the article for the intelligent building weak electronic system design installation lacked uniformity of line congestion, signals interfere with each other, operational reliability difference issues analysis, focused on the power supply and the AC and DC isolation, grounding and signal line fangrao, the weak electricity room integrated distribution design reference models and their combined removable fangrao, design of the Cabinet. Keywords: intelligent building control Automation (BA) integrated distribution mode fangrao Cabinet modulus outlet in recent years, building intelligent technology is developing rapidly, especially network communication technology development by leaps and bounds. Now many high-rise buildings are racing to introduce various weak integration system to improve building intelligent management, the realization of construction equipment management automation (BA), communication Automation (C A), Office Automation (0A). This is the modern trend in the development of high-rise buildings, but in the current operation implementation process, there are many issues to be perfect and resolved. For example: many high-rise buildings, the weak electronic systems for core a room distribution and wiring design and construction that has many problems: the latest national standard Atlas of the intelligent building weak electricity engineering design and construction Atlas (Atlas, 97X700) and the building electrical installation project Atlas (4 sets), etc., except for fire fighting and security monitoring, telephone station, electronic device, power distribution and wiring for a more detailed description of standard practices, on the other such as the computer room, floor control equipment room and closed-circuit television room, power distribution and cabling standard practices elaborated somewhat detailed and comprehensive, some practices describe too fuzzy. In recent years, the publishing of intelligent building design technical manuals (such as the North-East of East China architectural design Research Institute, Institute of architectural design and preparation of) and building weak electricity design engineering technical manuals (such as Liu Lin, Liang hua, Chen is Haefel 's), and so also are not on this issue in detail and depth. The existing civil construction electrical design code (JGJ/T16 a 92) on the subject of detailed and clear enough. So, now the majority of architectural design Institute, a professional electronic design and installation company on weak current room design is more rough, plot mostly similar principle pattern figure instead of drawings. Currently have strong, weak electricity systems installation technology level and the capacity of the installation of a very small company, but also by an electrical installation Company undertakes all the intelligent building weak electricity system, installations are not possible nor practical. Even weak electricity system integration cannot be installed by any one company alone, because many types of electronic equipment, the product installation companies have their own product advantages and technological advantages, intelligent building construction in the comprehensive consideration of quality, price and service, and so on factors must be weak electricity system integration Engineering Division of the functions of the system, divided into several weak electronic systems project: large power installation company can contract the entire building control automation systems engineering projects, such as: United States Honeywell (rohonyi Weir) Johnson (Johnson Controls), the United Kingdom Satchwell (rosace Ville), etc. in the agent installation company in China; small weak electricity installation company can contract to CCTV, electronic anti-theft, etc, this installation company too numerous to mention. This resulted in a real intelligent building weak electricity system integration process, strong electric installation company, weak electronic systems installed by default, the relative company independently carry out equipment and pipeline installation status, but the equipment system because of a lack of technical safety specifications, cooperate, coordinate is not well (for construction supervision departments therefore ineffective). So I visited and investigation of some smart building weak electricity equipment room almost without exception exist: different voltage level and frequency of the signal lines in the engine room the cross arrangement and the back of the device at each other through the interface, power configuration is not reasonable, electrical fire, leakage and signal interference and other hazards; system operating reliability is poor, room equipment maintenance and management of inconvenience.
To this end, the intelligent building weak electricity room integrated power distribution and wiring pattern. Intelligent building weak electricity room by nature and functionality can be broadly divided into: computer room, floor control equipment management room, PABX, fire alarm and control room, closed circuit television monitors in the engine-room and security. Considering that the above-mentioned electronic room basically have computer equipment, this article focuses on some computer equipment in the engine room to explore for peer and expert reference.
1 power supply
Electronic room equipment belonging to level load, you should use two dedicated trunk road into two located | independent power supply at the end of mutual technical. To use a smaller power capacity can be approached from level lighting load link arch | into power, when power failure rate is high, can be considered in the House vicinity-owned generator or increase the battery capacity. Computer equipment for the power requirements are of good quality, not only requires one of the ups, and the power supply voltage fluctuations in the +-10% in order to work properly. Some of the network data transmission equipment and even require a power supply voltage fluctuation in ± 5%. And intelligent building weak electricity system integration process generally is in building completed fine decoration, various construction equipment frequently used, power supply voltage is very difficult to meet these requirements. Intelligent building technology people use to commute time period, the power supply voltage is often beyond the soil 10% fluctuation range. A large number of observed data to illustrate this point. So, choose the design of uninterruptible power supplies for power supply (UPS):
(1) should make its output power greater than the electrical devices rated power of 1.3 ~ 1.5 times, rated discharge time should be 10 to 30 minutes.
(2) should meet against voltage fluctuations indicator, you should set before the UPS power regulator.
(3) the electrical equipment in rectifier is large, the load on the UPS power on setting before distribution circuit harmonic absorber to absorb higher harmonic, the output voltage, total waveform distortion is not more than 5% (single-phase output allow 10%), power quality poor areas should be set before the UPS device frequency deviation protector.
(4) the electrical equipment on the reliability and continuity of the request, select UPS power working mode: single-, parallel, redundancy and parallel redundancy. The bypassThe power supply shall meet the requirements of load capacity and characteristics. By-pass filter is set on, bring their own generator does not bypass the power straight for the load.
Design and construction and installation company must design when fully installed distribution room in understanding the power of objects and environment information as fully collect electronic room equipment and system information to do a power supply design and layout, thus reasonable to meet the needs of weak electrical equipment room. Electronic room should be located separate power management rooms, electronic equipment with a firewall and isolation, avoid power management, battery acid-base between noise liquid leakage and electrical fire and other accidents are propagated to the electronic equipment in the engine room. Weak-current equipment room and power management located single sector towards power management direction to an open connection door, consideration could be given in the electronic equipment room and power management settings between between glass observation window. Power management company should do cement ground for moisture-proof and moisture can block 0.3 ~ 0.5m high cement platform on hold ups. For sending and receiving data signals a heavy task, network server more computer room and floor control equipment management room, consideration should be given to select Smart UPS power, it will be the main power failure, self charging fault or other reasons, such as its energy storage capacity, does not supply this information sent to the host computer system monitoring, system monitoring host should have the appropriate hardware interfaces and power monitoring software, system data processor and server settings, such as the order for mandatory storage of their respective current data information, backup files, goes to sleep and to perform shutdown operations, avoid data transmitted disorder and computer control system malfunction, etc. Smart troubleshooting, UPS power, should send a signal to the system monitor host to enable it to restart, it restarts the system is activated and the data processor and server, dynamic real-time work equipment.
2 grounding
Electronic room electrical grounding there are three: (1) DC in (including logic and analog signal system grounding) (2) Exchange and (3) security and protection. The above three Earth grounding resistance values require no more than 4 Ω for intelligent buildings, reliable and economically viable grounding way is to use common grounding, lightning protection and grounding share a set of TN earthing device, using a S ground system. Exchange and security protection to separately from power supply line N and PE cable. Intelligent building unified grounding resistance is generally less than 1 Ω, author visits and research have been to Beijing, Shanghai, Chongqing and Shenzhen and Hainan some high-rise building project, their uniform ground resistance mostly 0.2 ~ 0.5 Ω, some high-rise building individual test point grounding resistance value of 0.8 Ω Max however. Of course, unified resistance should not be greater than 1 Ω requirement is a minimum limit, the specific projects should be as small as possible, such as the requirement to increase the number or take the grounding resistance reducing artificial to meet actual requirements (use high efficiency and grounding of no greater corrosion resistance-reducing agent). Here are a few highlights: the introduction of power ups power management between two way power supply, the main power adopts three-phase five core (3L + N + PE) insulated fireproof cables, standby power use LAN phase four-wire (3L + N) insulated fireproof cables. Main power supply cable PE cable in the power management asked changeover switch box as an auxiliary equipotential ground terminals. Need to do to the weak electricity room DC (such as PBX room and computer network equipment room, etc.) should be adjacent in the computer room, power exchanges, and security protection from computer engine room power management rooms, separate from the building and distribution room total equipotential ground bus located on two sectional | area of not less than the insulated fireproof cable 16mm2 (such as: single-core 16mm2, three-core and quad-core 6mm2 4mm2, etc.), in a DC ground of weak current room set special metal wiring box tandem they, do DC ground terminals for DC and device termination. Building distribution room total equipotential ground bus should surge arrester, spark gap or surge voltage suppress, protection equipment, prevent lightning earthing device potential rise, electrical equipment through grounding line counter, causing DC ground potential greater volatility caused by work in electronic equipment.
Weak current in the engine room the anti-static floor is apart from the high ground 0.3m. Along with four wall wires in the engine room 20x4mm flat steel or reinforced to activities in 6mm floor metal support PIN do more repeat grounding welding, near power management company with more than one side of the copper conductor insulated 6mm2 line wear steel pipe or PVC pipe access power management within the secondary equipotential ground bus to power the engine room floor surface is a secure and reliable equipotential plane, and shielding protects the floor under a variety of signal lines against electromagnetic interference, also isolate the floor, under different voltage and frequency signal lines of mutual interference. 3 distribution and cabling
Weak engine room power management attention between the power to take measures, lightning is not appropriate to use armored cable, the cable of metal jacketing and earthing connection. From the outside into the armored signal cable and shielded signal cable into the power room before taking measures that prevent lightning along the wall, or close to the mine-laying down lead in order to avoid being struck by lightning, and avoid lightning building, by lightning protection device has high-frequency electromagnetic interference. The cable into the power room, should be set metal wiring boxes (boxes) in which the cables coated metal (shield) back-to-back arrester or surge voltage suppress, and weak engine room Assistant equipotential ground bus with cross-sectional area of not less than 6mm2 copper conductor insulated wire connectivity, wear protective tube. It can also inhibit the cables in the transmission path received other adjacent interference generated by high-frequency electromagnetic interference signal, thereby effectively and reliably guarantee the quality of the signal transmission. From weak current room arch | application of signal wiring trunkings along the wall and ceiling installation, avoid and other electrical lines parallel glued laying. To avoid air conditioning, fire protection, heating and water supply and drainage, plumbing, and their spacing greater than 0.3m.
Weak current UPS power outlet pick set metal distribution box, the bottom margin to 1.4m concealed, if there are difficulties can also be wall mounted, according to the power specified in the engine room equipment load capacity and distribution is divided into single, three-phase circuit, with a small vacuum circuit breaker as C45N, DZ47 etc. line protection switch, box set secondary equipotential ground bus. For LANPhase output load imbalance, maximum one phase and minimum phase load for fundamental difference between the RMS current, not more than the UPS power rating of 25%, and maximum line current not exceeding the rated value. Electronic room lighting load and air-conditioning load not by UPS power supply, power supply, management should be by mutual investment and switch box set lighting power supply circuit and the sum is less than the rated power, 2kW of fan coil or air-conditioners distribution circuits power supply. In the engine room entrance and convenient location near the wall concealed lighting switch box or switch panel, air-conditioning outlet set in room activities ceiling wall or distance to the wall, 1.8m power rating greater than the sum of the air-conditioning load 2kW from weak current room floor nearby power or illumination distribution box load distribution, lighting and air conditioning load lines are along the ceiling or wall laying, avoid weak engine activities under the floor through. The other by the mutual technical switch box to configure the power management in the inspection and repair of single phase power supply circuit, in power management and various wall distance between 0.3m set maintenance power outlet, the prohibition of the use of 2kW above high power inductor of electric tools, do require the use of such tools as well as three-phase overhaul equipment, you should use the construction of mobile power strips from weak current room floor nearby power or illumination distribution box directly uses power. Electronic room equipment tables, cabinets, and the distribution frame in three ways.
Here to power management in the engine room to the right, for example, other situations may be similar. As shown in Figure 2, from the UPS power distribution box search | out of distribution line wear thin steel tubes or flame retardant PVC pipe from weak current room activities under the floor to the row of equipment for laying the table, the Cabinet and distribution frame, from the back of the hole with thread activities floor (optional or customize this floor, thread hole usually 20 ~ φ φ 32 m m) cited on wear protection into metal rail socket wiring duct, Cabinet or distribution frame. Metal rail socket trunking with bolts installed in the device table back margin raised floor 0.1 ~ 0.3m suitable. General power docking device with power cord 1.0 ~ 2.0m, device table height generally 1.0m following, fully meet the power plug distance requirements, here is an explanation of the required equipment table device typically single-phase load J if there is a three-phase devices should be placed for the landing, dedicated circuit ground socket box (junction box) distribution. Metal track Pack within card socket flutes modular power supply socket, the socket is not card loaded with metal cover parts (each 0.2m long suitable) snap, to security and the role of electromagnetic shielding. Modular power outlet minute termination and zoomlion pieces.
This socket holes (as shown in Figure 3, positive) on two or three very external device plug compatible generic, according to need can also make incidental switch or shield, you can easily extend and dismounting, card mounted on metal track outlet firmly within the trunking, reliable and secure, and press the device table on the device location and number of grouping configuration module in the power outlet, group by and the power supply cord with the models of cable connection, try to make the device table of device power plug wire vertical cross table into modular power outlet, the power connection on the back of the device table neat, safe, beautiful and easy maintenance.
Signal line cable in activities under the floor from the Cabinet, distribution frame to the device application trunkings along the device table or room main plane vertical and horizontal installation, from the back of the device table movable floor stringing the bow on the hole into equipment l (attention not to the power supply line with movable floor stringing hole, and spacing greater than 0.1m). Signal cables to avoid laying down the room wall case and strong wire pipe cross, etc. Table of signal connection between the devices is the short-term (less than 3m) along the device back desktop downlead suspended, but not in the device table back side air; is a long line of (length greater than 3m) from the active thread hole under the floor (I) wore thin pipe laying in activities under the floor.
This is a science to ensure a reliable supply of electronic room safe, and a variety of different voltages and frequencies of the signal cable laying security, mutual isolation, much neater and more elegant and convenient maintenance.
4 fangrao cabinet design
Electronic room Cabinet, single side source distribution frame (single-row, set the wiring Cabinet set shelf placement within the upper part of the active devices such as routers, and hubs) reasonable wiring to ensure electrical safety, mutual isolation and maintenance convenience. At present most finished cabinet and single side source distribution frame exists electrical hazard: strong, weak lines cross in the back of the Cabinet, Cabinet power distribution is not uniform standards. Most of the current practice is to use the back of the Cabinet, top, bottom, or spare parts of any substantial protection switch and power strips, and some even have power strips-suspended in the air (sometimes on Cabinet for operations management may inadvertently result in this case), this can easily lead to bad or leakage power failure occurred in the device, and even find | play electrical fire. To this end, the authors conducted fangrao cabinet design ideas (that is, the problem with the above modification of present in the finished cabinet and distribution frame): first of all from the overall design of the Cabinet on, should be greater than the width of the cabinet can 0.5m across the floor of the two activities supporting crossarm (active tiles typically 0.4x 0.4m2 and 0.5x 0.5m2 square plate), thus ensuring support and firm to laminate, incoming and outgoing lines across the floor. Cabinet height is greater than 2m, for ease of operation and maintenance. Enter width can be maximum built-in device width + 0.3m design depth. Cabinet bottom bracket with pulley makes Cabinet become portable, so easy to install and adjust and repair, surface design for single-leaf door pull-style facade is inlaid Plexiglas, metal border for observation and monitoring. Secondly, the top or inside the Cabinet side mounted 1 ~ 4 embedded cooling exhaust fan (power 100W), thus ensuring consistent with electrical cabinet temperature rise, making use of standard built-in equipment from electrical heating effects remain functional. Third, according to the number and size of built-in equipment designing hierarchical shelves, according to the incoming and outgoing lines on the number and type design tlb, have wire rack and splitters, etc. General design of the Cabinet upper display active equipment, lower do distribution frame and entering and leaving the cable interface. In the upper part of the Cabinet is the source of the metal plate back installation, by the Cabinet top to the lowest powered equipment, metal plate rear Cabinet is divided into two parts, in the active device's power supply connector holes(Aperture to φ φ 40 ~ 60 suitable), weak-signal line cable, wire, all types of jumper and signal connections between devices on a metal diaphragm before laying. Active device power cable perforation after laying in metal plate rear. In the metal plate rear wall socket metal rail installation on trunking and modular power supply socket for single-phase devices (including cabinet cooling fan) docking. Groove does not fit socket parts used card metal cover card. In the metal plate rear side pole three-phase 5 installed on your (compatible docking quadrupole) socket or 3-phase protection switch for three-phase devices docking or termination, Cabinet back doors with single fan-open type metal doors. On Cabinet enclosures and metal components for prepainted, prevent paint and rust.
5. concluding remarks
With the rapid development of intelligent building weak electricity system, and its integrated technology have diversified to existing electrical systems and technology model brings many new problems and issues. This article in accordance with the current smart building design and installation of some of the problems existing in the current room integrated distribution patterns, and the design of the Cabinet Fangrao. Seek to address the power configuration, AC and DC isolation, grounding and signal line fangrao, thereby optimizing the power room layout and wiring, guarantee reliable power supply, electrical safety and various signal cable transmission quality, power failure, leakage, crosstalk and fire hazards. Reference documents
[L] intelligent building weak electricity engineering design and construction Atlas and Atlas 97X700. China building standards Design Institute published .1998, 1st Edition
[2] civil construction electricity design specification JGJ/T16-92
[3] Lu Everbright. construction electrical installation project Atlas (Chapter 4). the electric power publishing .1998, 1st Edition
[4] Liu Lin. comprehensive wiring system design. Electronic industrial press, 1998, 1st Edition
[5] King thick Yu. electronic information device security requirements and anti-interference. construction electricity, 1998, no. 3
[6] beam Vladimir Pro-intelligent building intelligent equipment of power supply system. construction electricity, 1999 No. 1