The installation and construction of overhead cable
Through statistical analysis of line fault, due to construction, installation and connection and other factors caused the failure is often much greater than the probability of failure caused by faulty wire cable body. Therefore, to correctly use overhead cable and related accessories, in addition to specifications for design and construction, we must also pay attention to the following aspects of the problem: ⒈ cable laying installation by a qualified professional unit or professionals, does not comply with the relevant norms of construction and installation requirements, it may cause the cable system can not function properly.
⒉ manpower when laying cable, unified command and control rhythm, every 1.5 to 3 meters cable with one shoulder, side discharge side pull, slowly cast.
⒊ mechanical cast cable, generally use a dedicated cable laying machine tools equipped with the necessary traction, traction size appropriate to control uniform, in order to avoid damaging the cable.
⒋ cast cable before, to check whether the cable appearance and head intact, note the direction of rotation of the cable reel when cast, do not crush or scratch the cable sheath, not to low temperature in winter when the beat way to school straight cable, in order to avoid insulation, sheath cracking.
⒌ When laying the cable bend radius is greater than a predetermined value. Before cable laying installation, the insulation resistance between the rear with 1000V megger cable conductors are normal, and according to the cable model specifications, different length and ambient temperature on the measurement results be properly corrected, the small size (less real 10m㎡ core conductor) cable should measure whether the conductor off.
⒍ such as burying cable, pay attention to soil conditions, laying cables under the general building not less than 0.3 meters deep, soft, or the surrounding environment has become more complex, such as arable land, construction sites or roads, there should be some buried depth (0.7 to 1 meter) to prevent accidental damage to buried cables, if necessary erect signs.