The design and construction of the installation of electric wire and cable installation shall be carried out according to the relevant provisions of 50217-94 GB "code for design of electric cable design", and the necessary cable accessories (terminals and joints) shall be used. The operation quality, safety and reliability of the power supply system are not only related to the quality of the wire and cable, but also to the construction quality of the cable accessories and the line.
Through the statistical analysis of the line fault, due to the construction, installation and connection and other factors caused by the fault is often much more than the fault caused by the fault of the wire and cable. Therefore, the correct selection of wire and cable and accessories, in addition to the specification requirements for design and construction, but also should pay attention to the following aspects of the problem:
The cable laying installation must be performed by a qualified professional institutions or professional personnel, not in conformity with the relevant provisions of specification requirements of construction and installation, may lead to abnormal running of the cable system.
The human to the laying of cables should be unified command rhythm control, every 1.5 ~ 3 meters with one shoulder cable, pull put side, slowly casting.
HAZOP machinery casts a cable, the general use of special cable laying machine and equipped with the necessary traction tool, the traction force appropriate size and uniformity control to avoid any damage to the cables.
The cast of the cable, to check the appearance of the cable and head are in good condition, when the cast pay attention to the cable tray rotation direction, not flattening or scrape wound cable outer sheath, in the low temperature in winter never to beating to straighten the cable, lest insulation and sheath crack.
The bending radius of cable laying is greater than the specified value. In the installation of cable laying, 1000V megohm table measuring cable between each conductor insulation resistance is normal, and in accordance with the cable types of specifications, the length and the ambient temperature is different on the measurement results are properly corrected, small size (10mm below 2 solid core conductors) cable should be measured volume conductor whether on-off.
The cables, such as directly buried installation, attention should be paid to the soil conditions, general building cable of the buried depth of not less than 0.3 meters, a soft or the surrounding environment is complex, such as farmland, construction sites, road and so on to the buried depth (0.7 ~ 1 m), to prevent direct buried cable accidental damage, if necessary should be obvious signs erected.
