【 Weak current College 】 intelligent construction elements

Coordination of civil works and other works, attention and follow its construction law.

1. reserved hole and bury pipelines and the coordination of civil works

In civil infrastructure construction, should do well grounded project leader hole, ground piping of over the wall holes, cable over the wall protection tube and into the embedded line pipe.

2. wire frame construction and civil engineering support

Trunking mechanism installation construction, civil engineering, basic and other after the end of the pipeline (wind pipe, sewerage) installed at the same time as, or slightly later than pipeline installation for a period of time, but you must resolve the power wiring duct frame and piping in space location reasonable integration and cooperation.

3. pipeline construction and decoration works with

Wiring and threading work in civil engineering is completely finished, and decorative works carried out at the same time, the schedule should be avoided since the end of the project, which resulted in the laying of the difficulties of Threading.

4. the control room arrangement and decoration works with

The control room of the decoration and the overall decoration project of synchronization, the weak electricity system equipment positioning, installation, wiring connections should be at the end of the decorative works Basic.

3. the commissioning stage

First single equipment or parts debugging, and debugging a local or regional, final overall system debugging, debugging the system type.

4. the acceptance stage

The engineering acceptance into hidden project and minute projects and completed projects in three steps

1. hidden project acceptance

Weak is the installation of line pipe embedded, buried cable, grounding, etc all have a secret project, which in the next procedure before construction, construction unit representative (or supervisor) concealed work check acceptance, and conscientiously lose good hidden works acceptance procedures into technical archives.

2. sub-item project acceptance

The end of one phase of the project, or a sub-item project completion, construction unit, in conjunction with the design units in sub-item acceptance; some individual projects from the construction units to declare local authorities for acceptance.

3. acceptance

Engineering completion approval is on the entire construction project of comprehensive check acceptance. In the project final acceptance before acceptance of construction units, check the relevant technical data, engineering, quality, and timely resolution of issues. The construction unit, in conjunction with the design and construction of the units reporting by local authorities for acceptance.

(2), construction technology

In the construction process in strict accordance with the standard for quality inspection and assessment of the quality of itemized check operation, after the completion of the construction quality assessment and quality assurance information prepared to ensure the delivery of projects to achieve the design requirements and meet the use feature.

First, the laying of electrical circuits

A £ ® general provisions

1. cable (line) in the laying of the former, do look and on-check, and DC 500V megohmmeter measure insulation resistance, its resistance is not less than 5 M Ω; when there are special provisions should be in line with its provisions.

2. line by shortest way set laying, horizontal even vertical, tidy, should not be crossed.

3. line should not be laying in vulnerable to mechanical damage, corrosive media releases, humid, and there is a strong magnetic field and strong electrostatic interference zone; if necessary, take appropriate measures to protect or shield.

4. When the line more than 65 ° c ambient temperature, insulation measures taken; situated may cause a fire of fire places, and fire prevention measures.

5. line is not suitable for high temperature of the parallel laying in the process equipment, piping above and corrosive liquids of process equipment, piping.

6. line and adiabatic process equipment, pipe insulation distance between the surface should be more than 200 mm, and other process equipment, piping between the distance should be greater than 150mm.

7. wiring of terminal line Department, and after the building expansion joints and settlement of every department, should have adequate redundancy.
8. line should not have intermediate connector, when you cannot avoid, should the cable box or junction box, connector in the wiring should press; when using the welding application non-corrosive of brazing. Compensating cables should press. Coaxial cable and high-frequency cable should be used for the connector.

9. the laying of the road, it is not appropriate in concrete beams and columns drill mounting holes.

10. line laying, should carry out school lines and numbers and, in accordance with the provisions of article 1, measure the insulation resistance.

11. a measuring line insulation, you must set the connected devices and components on the fracture.

B. cable laying

1. ambient temperature during laying of cable is not less than-7 ℃.

2. laying cables should be reasonable arrangements should not be crossed; laying should prevent cable and cable and other hard body friction between; fixed, tension should be moderate.

3. multi-core cables, bend radius should be not less than 6 times the outer diameter.

4. signal cable (line) and cable crossover should angles; when the parallel laying, the distance between them should be consistent with the design requirements.

5. in the same area, in the different signals, different voltage cable layout should be classified; for AC power lines and chain line, the application partition and no shielding signal line separates the laying.

6. the cable along the bracket or online tank installation should be firmly fixed in the following places:

(1) cable angled slope exceeds 45 ° or vertically, in each bracket.

(2) cable angled gradient of not more than 45 °, horizontally, at intervals of 1 ~ 2 brackets.

(3) and compensation for redundancy and protection on both sides of the pipe endsThe first, second, the two brackets.

(4) the introduction of the dashboard (carton) 300 ~ 400mm before.

(5) into the junction box and line box 150 ~ 300mm before.

7. trunking vertical stratification, the cable should be installed in accordance with the following provisions order from top to bottom:

Instrumentation signal lines;
Security chain line;
AC and DC power supply line;
8. that the signal line and laying a strong magnetic field and strong electric electrical equipment NET distance between preferably more than 1.5m; when using shielded cables or wear metal protection hose, and online tank installation, preferably more than 0.8m.

9. cables laid in the trenches, laying in the brackets or trunking. When the cable into the buildings, the cable channel and buildings between isolation seal.

C. other requirements

Wire wear protective tube before cleaning, wearing a pipe should not damage wire.
2. signal wiring, power supply lines, chain line and has the special request of instrument signal line, should adopt their own protective tube.

3. the dashboard (box) Terminal Board at both ends of the lines shall be numbered by construction drawings.

4. each of the terminals allows at most two cores received.

5. wire and Terminal plate, instrumentation, electrical equipment, etc., should have adequate redundancy.

Second, power equipment installation

A £ ® power supply system installation

1. power engineering of power supply units should check the device before installing the appearance and technology performance and meet the following requirements:

2. relay, contactor and switch should act in close contact with flexible, and no corrosion and damage.

3. a fastener, terminals should be intact and free from dirt and rust.

4. equipment accessories, performance conforms to the requirements of the installation manual.
B £ ® power equipment installation

1. equipment installation should be strong, much neater and more elegant, Terminal number, use of signs and other signs, should remain intact, writing correct clear.

2. fixation device so that the force uniform device.

3. instrument boxes installed power supply units whose bare charged body mutually or between other bare conductors between the distance shall be not less than 4mm. When unable to meet, each must be reliable insulation.

4. power supply box installed in the concrete wall, pole or basis should adopts expansion bolts fixed and should satisfy the following requirements:

(1) box height of Center distance ground should 1.3 ~ 1.5m;

(2) arranging installed power supply box, should be neat and tidy.

5.UPS equipment is installed, you should check the reliability of automatic switching device, switch time and switching voltage value should meet the design requirements.
6. the regulator should check before using their regulator, voltage fluctuations in the value should be consistent with the provisions of the installation manual.

7. Rectifier in use before checking its output voltage, the voltage value should be consistent with the operating instructions before installing.

8. power supply units with live parts and metal shell insulation resistance between, 500V megohmmeter measurement, should be not less than 5 M Ω. When the installation manual, there are special provisions should be prescribed.

9. power transmission, system all power supply switch should be in the position of the "secondary", and you should check the melting capacity of secondary device.

Third, the weak electricity system grounding

A £ ® general provisions

1. the weak electricity system grounding, by purpose have protective grounding and functional grounding. Protective earthing is divided into: shockproof grounding, lightning protection and grounding, anti-static grounding and electrical erosion grounding; functional grounding is divided into: work grounding, logic ground, screened Earth and signal ground. Different ground have different requirements, should press ground construction design decisions.

2. need a grounded weak electricity system earthing devices should meet the following requirements:

(1) when piping using electro-galvanized pipe, apart from the design clearly, tubes and pipes, tubes and metal box connection after having to crossover, but should comply with the following provisions:

1) using thread connection of the pipe, the pipe end thread length should be not less than the length of the fitting 1/2 threaded surfaces must be smooth, no corrosion, defects in the thread should be coated with conductive power complex full-fat or fat-corrosion. After connection, thread 2 ~ 3 should be exposed.

2) pipe using a tightening screw connections of the casing, the screws should be tightened; place in vibration, tightening screw should be loose control measures.

3) pipes and a box of the connection should not be used plastic na child should be used in conductive metal that child.

4) PE pipe has a light line, each junction box should line-connected and PE.

(2) when piping using electro-galvanized pipe, pipe design also requires crossConnect, between the need to comply with the following provisions:

1) downlead pipe should not be used for fusion welding crossover design, should be used to specify the dedicated next line clamp crossover.

2) buried or placed in concrete in tube, without applying the line card jumper, jumper can be taken for fusion welding.

3) if the tube dress with nude soft PE copper wire, electric pipe can not crossover. This line must match its PE of every connected to junction box.

(3) tubing with black mild steel pipe, if the design does not require a crossover, you do not have to crossover. If the crossover between the black and Tan tube and junction box with round steel crossover between, on one side of the weld should not be less than the length of the crossover crossover round bar diameter 6 times; black and galvanized tray cross-over between the black mild steel tube end welding a copper bolts, no less than 4mm of copper conductors are connected with galvanized cable tray。

(4) when the ELV are made from PVC pipe, to avoid interference, power piping should be avoided and the strong power piping of the parallel laying of the parallel laying, if necessary, the distance should be greater than 0.5m apart.

(5) when laying by ELV trunking, trunking to separate ELV; when it is necessary to lay down the same trunking, ELV separated metal separators between applications.

B £ ® telecom equipment grounding

1. to prevent external voltage hazards safety and damage to equipment, electrical interference suppression, and ensure the normal work of communications equipment, telecommunications equipment should be grounded in the following sections:

(1) DC power supply, telecommunication equipment rack and enclosure; standing communication cable metal sheathed and shielding layer.

(2) AC distribution panel, Rectifier screens exposed electrical power supply equipment.

(3) DC power distribution over the exposed parts of the screen.

(4) and DC-telecommunication equipment rack, machine box and rack, machine box not insulated power rectifier conductive parts of the exposure.

(5) cables, overhead lines and associated needs grounding parts, such as the arresters and surge arrester, protection gaps, etc.

2. when the low-voltage distribution system to take the TN-PAL power supply, telecommunication equipment if the requirements strictly limit the effects of power frequency AC, and telecommunications equipment are not easy to do and the stations of various gold is a component of the insulation should be used; when TN-S modulation interference requirements are not too strict, you can use TN-C format; when telecommunications equipment of leakage current in 10mA and above should be used TN-S format.

3. power distribution panel, Rectifier screens exposed reinforcement conductive parts, when the device with the frame, machine frame is connected in the electric, still need and PEN line PE lines or connected.

4. when taking IT standard power supply, telecommunication device leakage current in 10mA above, in order to avoid malfunction protection device, take the double coil power supply transformer, its primary side access IT system, secondary side in TN mode power supply, power supply equipment grounding and TN mode are the same.

5. telecommunications equipment work grounding, General requirements may be set individually and building work grounding transformers with a grounding device. However, it must be through a dedicated grounding wire insulation and earthing device connected.

6. telecommunications equipment using common grounding, the grounding resistance should not be greater than 1 Ω, expressing both cross-sectional area of not less than the copper conductor insulated wire 25mm2 wear pipe laying into common ground electrode. When using the Foundation jointly reinforced as extremely, connections should be copper, iron and transition joints.

C £ ® electronic equipment grounding

1. electronic equipment signal grounding, logical, grounding and shielding and grounding, power and protection earthing and grounding, generally share a grounding, its Earth resistance not more than 4 Ω; when electronic equipment grounding and Lmin grounding, lightning protection combined with a grounding, its Earth resistance not more than 1 Ω. Shielded grounded as a separate setting, its grounding resistance normally 30 Ω.

2. the difference of anti-interference ability, the electronic equipment and its grounding should be separate, lightning protection and earthing between distance should be more on 20m anti-interference ability strong electronic equipment, the distance between the discretion to reduce, but not less than 5 m.
When electronic equipment grounding and lightning protection and earthing using common grounding device, in order to prevent lightning strikes back and when subjected to ensure equipment safety, should be buried armored cable power supply.

3. cable shield should be grounded, to avoid interference current, the signal cable and 1MHZ and following low-frequency cable should be a little above the ground; 1MHZ, to ensure the cable shield to ground potential, should take more grounded.

4. in order to avoid the loop current, instantaneous current impact, radiating ground system should use the grounding; to eliminate the next venue of potential difference and avoid interference with each other, ring earthing system should use the equipotential; on hybrid grounding system, electronic equipment, with radiating ground within the electronic device external use ring earthing system.

5. grounding ring bus section, when electronic equipment frequency in 1MHZ above, foil 120mm×0.35mm; below the 1MHZ foil mm×0.35mm.

6. electronic equipment grounding electrodes should be laid underground levels, resulting in rake or star.

D £ ® data-processing equipment grounding

1. data-processing equipment grounding resistance is 4 Ω, AC power frequency grounding and lightning protection and earthing and grounding resistance when Ω to 1.

2. for leakage current 10mA than data-processing equipment, its host indoor metal body should be connected into one, the connector can use 6mm2 of copper conductors or 25mm×4mm galvanized flat steel, and Earth, Earth resistance not more than 4 Ω.

3. in order to reduce the skin effect and channel impedance, DC work grounded down lead should pick tele multi-core copper conductors, section should not be less than 35mm2, when you need to improve the signal of working conditions, the use of multiple-unit copper wire.

4. DC work grounding and Exchange work grounding as not using common grounding, the power difference between the two should not exceed 0.5V to avoid interference.

5. input signal cable wear steel pipe laying, or laying in with metal cover of metal cable tray, steel pipe and cable tray should be grounded.

E.-acoustic, TV system grounding

Audio, TV system grounding resistance is 4 Ω, industrial television system such as device capacity ≤ 0.5kVA
, Grounding resistance may not greater than 10 Ω. Mounted in a building at the top of the antenna metal base must be lightning network at the top of the building, consisting of lightning systems, by at least two different direction down lead or main bars in the building for grounding.

To avoid groundingPotential difference caused by stray wave interference with communication, CCTV and industrial TV must be in the grounding.

TV system of the transmission cable wear metal pipe laying, metal pipe to grounded to prevent interference
Information outlet installation requirements:

(1) installed on the floor or ground shall be fixed in the terminal box, Jack Panel has the form of vertical and horizontal; junction box cover can be opened and should be tight and waterproof, dustproof. Junction box cover should be flush with the ground.

(2) installation on the wall, above the ground, such as ground using 300mm movable floor, should be assumed to do within the raised floor inch.

(3) information outlet base, fixed to the construction site conditions, the use of expansion screws, air, etc.

(4) screws to tighten the loose phenomenon should not be generated.

(5) information outlet should have the labels, colors, graphics, text indicates that the terminal equipment type.

(6) the installation location should meet the design requirements.

5 £ ® cable tray and channel installation requirements:

(1) bridge and channel installation location should be consistent with the provisions about construction plans, should not exceed 50mm deviation.

(2) cable tray and grooved horizontal degrees per square deviation should not exceed 2mm.

(3) vertical tray and channel should be perpendicular to the ground and not tilt, vertical deviation should not exceed 3mm.

(4) two channel stitching Department level deviation should not exceed 2mm.

(5) vertical installation should keep the hanger, neat firmly, without tilt phenomenon.

(6) metal cable tray and grooved and internode should contact good, installed securely.

6. installation frame, wiring devices and metal pipe, duct grounding should meet the design requirements and maintain a good electrical connection.

D £ ® cable laying and support protection mode

1. cable laying

(1) cable laying General should meet the following requirements:

1) cable layout before check specifications, routines, routing and location and design requirements.

2) cable layout should be straight, not producing twisted, loop, etc., should not be subject to external forces of extrusion and injury.

3) cable ends before the cloth should be labeled to indicate the start and end position, the labels should be clear, is written and correct.

4) power cable, signal cable, twisted pair cable, optical fiber cables and building other weak electricity system cable layout should be separated. The cable between the minimum net margin should meet the design requirements.

5) cable layout should be redundant. The rooms, twisted pair cable between devices reserved length usually 3 ~ 6m, workspace 0.3 ~ 0.6m; fiber-optic cable in the device-side length generally reserved for 5 ~ 10m. There are special requirements should be set aside by the design requirements.

6) cable bend radius should satisfy the following requirements:

① unshielded twisted pair cable 4 on the bend radius should be at least 4 times the cable diameter, in the construction process should be at least 8 times.

② shielded twisted pair cable bend radius should be at least as cable diameter 6 ~ 10 times.

③ twisted pair cable backbone of bend radius should be at least 10 times the cable diameter.

④ cable bend radius of at least least optical cable outer diameter of 15 times, in the construction process should be at least 20 times.

⑤ cable laying, traction, hanging the fulcrum of the cables should not be greater than the spacing between 1.5m, cloth cable traction force, should be less than cables allow tension of 80%, for the moment the maximum traction cable should not exceed the permitted tension cables. Laid in traction, main traction cables should be in the cable core strengthening.

⑥ cable layout process in order to avoid stress and distortion, should produce qualified end of traction. Such as mechanical traction, according to the length of the cable traction, cloth on the environment, on factors such as the traction tension selection concentrated traction or distributed traction.

⑦ cloth fibre-optic cable, optical cable reels spin cloth with fiber-optic cable, optical cable traction speed generally 15m/min. Optical out spare Office to protect armed relaxation in radians, and have a buffer of allowance, and should not be too much to avoid cable back button appears.