(1) The laying of instrument electrical lines shall conform to the current national standards, Code for Construction and Acceptance of Cable Lines in Electrical Equipment Installation Engineering GB50168-92-92 and Code for Construction and Acceptance of Wiring Engineering in Electrical Equipment Installation Engineering 1kV and below GB? 50258-96.
(2) Before laying cables and wires, visual inspection and continuity inspection shall be carried out. The insulation resistance shall be measured with a DC 500V megohmmeter, and the insulation resistance of lines below 100V shall be measured with a DC 250V megohmmeter, and the resistance value shall be not less than 5 m; When the design documents have special provisions, they shall comply with the provisions.
(3) Visual inspection and optical fiber continuity inspection should be carried out before optical cable laying; The bending radius of the optical cable shall not be less than 15 times of the outer diameter of the optical cable; The bending radius of plastic-insulated and rubber-insulated multi-core control cables should not be less than 10 times of their outer diameter.
(4) Cable laying shall be arranged reasonably, and laid in a centralized way according to the shortest path, so as to be horizontal, flat and vertical, neat and beautiful, and shall not cross. Friction between cables and between cables and other hard objects should be avoided when laying; When fixing, the tightness should be appropriate.
(5) The clear distance between the exposed instrument signal line and the electrical equipment with strong magnetic field and strong electrostatic field should be greater than1.50m; When using shielded cable, it should be laid in a covered metal cable trough through a metal protective tube, which should be more than 0.80m..
(6) When the instrument cable and power cable are laid crosswise, they should be at right angles; When laying in parallel, the distance between them should comply with the provisions of the design documents. When cables are laid in tunnels or passages, they should be laid on supports or cable troughs.
(7) When cables are laid in tunnels or passages, they should be laid on supports or trunking. Should be tied and fixed to prevent the cable from loosening. Cables with different signals and different voltage levels in the same trunking shall be arranged in categories; For instrument AC power line and safety interlock line, metal partition should be used to lay them separately from unshielded instrument signal line.
(8) The lines should not be laid in the position that affects the operation and hinders the maintenance of equipment and pipelines, and should avoid vehicles, pedestrian passages and lifting holes.
(9) When the ambient temperature around the line exceeds 65℃, heat insulation measures should be taken.
(10) The line should not be laid above high-temperature equipment and pipelines, nor under equipment and pipelines with corrosive liquid.
(1 1) The distance between the line and the insulation layer of thermal insulation equipment and pipelines shall be greater than 200mm, and the distance between the line and other equipment and pipeline surfaces shall be greater than 150mm.
(12) When the line enters the room from the outdoor, it should be waterproof and blocked. When the line enters outdoor panels, cabinets and boxes, it should enter from the bottom and be waterproof and sealed.
(13) The terminal connection of the line and the expansion joints and settlement joints passing through the building shall be redundant. When the cable enters the building, the cable channel should be isolated and sealed from the building.
(14) cables should not have intermediate joints. When it is inevitable, it should be connected in the junction box or cable box, and the connector should be crimped. When welding is adopted, non-corrosive flux should be used. The compensation line should be curled. Coaxial cables and high-frequency cables should use special connectors.
(15) After the line is laid, it should be corrected and labeled. Cables and wires entering the instrument panel, cabinet and box from the outside shall be routed after the continuity check and insulation resistance check are qualified.
(16) Wiring in instrument cabinets and boxes shall be laid in trunking. When laying open wires in a small junction box, cables and wire harnesses shall be fixed with ties made of insulating materials, and the distance between the ties shall be 100 ~ 200mm.
(17) The wiring of the instrument shall meet the following requirements:
Before wiring, the wiring shall be calibrated and the terminals shall be marked; Labels shall be correct, clear and indelible.
There should be no connectors for the lines in the cabinet and box, and the insulation protection layer or wire core should not be damaged during wire stripping. Peel the rubber insulated core wire and shielded wire from the outer sheath, and add an insulating sheath. The connection between cable and terminal should be uniform and firm, with good conductivity; Each terminal is allowed to connect two cores at most. The terminals of multi-strand cores shall adopt lugs, and the connection between wires and lugs shall be crimped.
(18) The terminal board shall be installed firmly. When the terminal board is at the bottom of the instrument panel, cabinet and box, the height from the foundation surface should not be less than 250 mm
When the terminal board is at the top or side, the distance from the edge of the panel, cabinet and box should not be less than 100 mm, and when multiple groups of terminal boards are installed side by side, the clear distance should not be less than 200 mm.
(19) When wires are connected with terminal boards, instruments and electrical equipment, redundancy shall be reserved. The spare core wire should be connected to the spare terminal, or reserved according to the maximum length that can be used, and marked with the spare wire number according to the requirements of the design documents.
(20) When measuring the insulation resistance of cables, the connected instruments, equipment and components must be disconnected.
The connection method and test requirements of optical cable and optical fiber shall conform to the provisions of the product manual. Optical fiber connection shall be operated according to the process method specified by the manufacturer and welded with special equipment. During the connection operation, the optical fiber should be prevented from being damaged or broken. Before and after optical fiber connection
The optical fiber shall be tested.
(2 1) Cable laying of integrated control system and digital communication lines shall meet the requirements of design documents and product technical documents; The special cables attached to the equipment shall be laid according to the instructions in the product technical documents.
(22) Instrument signal line, instrument power line, safety interlock line, compensation line and other special instrument lines shall adopt their own protective tubes.
(23) The compensation conductor should be laid in the protective tube or cable trough, and should not be buried directly; When no switch or cold end temperature compensator is used between the compensation conductor and the measuring instrument, it is advisable to directly connect the compensation conductor and the instrument; When the compensation conductor is connected in the middle or terminal, the wrong polarity shall not be connected.
(24) The compensation conductor should not be laid in the same protective tube with other lines; The protective tube should be cleaned before the compensation line and conductor pass through the tube, and the conductor should not be damaged when passing through the tube.
We may be a little unfamiliar with the instrument line, but the instrument line is very important. Rabbit reminds us that we must pay attention to the phenomenon of cable leakage, because if leakage occurs, it may spread through various conductors, such as water, which is the most common conductor and poses a threat to our life and health, so we should carefully remember the cable standards, which is also responsible for our lives. The rabbit will stop here.
Tubatu Online provides you with "every decoration quotation, 1-4 local decoration companies, 3 sets of decoration design schemes" and the decoration pit avoidance strategy for free! Click this link:/Zhu Ye /zxbj-cszy.php? to8to _ from = SEO _ zhidao _ m _ jiare & amp； Wb, you can get it for free ~