This type of installation provides good cooling conditions of the wires (cables), and the possibility of replacing them free access to them during the operation. Trays wirings produce sections of 2 m in length: the weld – a width of 200 and 400 mm, perforated – 50 and 100 mm. Trays mounted on at least 2 m above the ground or grounds maintenance; in areas served by specially trained personnel, the height of the trays and baskets not specified. Metal trays NL (Fig. 1) mounted on modular cable designs, the elements of building and technological structures, brackets and hangers. Step of fixing the cables – 250 mm. All connections for the installation and repair perform threaded clamping pieces of the process map. For reliable electrical contact at the joints straight painted tray flanges must be galvanized.
Electrical contact support elements with straight-colored bins provided by lock washers or cleaning up the site of contact. Operations wiring is in the trays in a specific technology sequence. First, a cord mark out the route in compliance with the mounting of the support and the support structures and points of attachment to the building elements of the building. The distance between fixing points Trays shall be equal to 2-2.5. Then, install or support structures are hung on brackets or consoles, perforated strips and profiles, fixing them or spacer plugs were shot. Supporting structures welded to the embedded parts of metal structures and buildings, or suspended in the spans of shops for carrying cables and cable hangers guys.
When crossing the tray with the distance from the pipeline before the pipeline supporting structure must be at least 50, with a parallel pursuit – not less than 100 mm for pipes with hot liquids or gases, respectively, at least 100 and 250 mm. After these operations of individual sections of the trays are collected in blocks 6-12 m, connecting them with strips of bolts. When laying boxes for cable suspension provide a bias towards the descent to the power consumers. Next, prepare a dimensional piece of wire in the ground and their connections at the ends removed isolation prozvanivatsya, twisted veins that produce the correct connections in the right places or squeezing a box set, harvested in bunches, bandazhiruyut, label tags. The number of wires in the bundle must not exceed 12 outer diameter of the beam – 0.1 m. The distance between the bandages on the horizontal beams of 4.5, the vertical – no more than 1 m.