Cable tray specifications are generally how to choose
First, the cable bridge type and variety of options . need to shield the electrical interference cable network or protective external (such as: corrosion solution, flammable dust and other environmental impact) requirements, should use (FB) Composite anti-corrosion shielded cable tray (with cover) . strong corrosive environment should be used (F) composite epoxy resin anti-corrosion flame-retardant cable bridge. Arm, bracket also use the same material to improve the service life of the bridge and accessories, cable tray. In the easy fouling and other needs to cover the environment or outdoor places should be covered plate. . in addition to the above circumstances, according to the scene also the environment and technical requirements of the choice of tray, trough, cascade, glass anti-corrosion flame-retardant cable bridge or steel ordinary bridge. In the easy fouling and other needs to cover the environment or outdoor places should be covered plate. . in the public channel or outdoors across the road section, the bottom of the bottom of the cascade should be pad or in the use of the tray tray. Large span across the public channel, according to user requirements to improve the load capacity of the bridge or the use of rack. . large span (& amp; 3m) to use composite bridge (FB). . outdoor to use composite epoxy bridge (F).
Cable bridge specifications: . in order to prevent the cable tray specifications size is too large or tight, "civil building electrical design specifications" (JGJ16-2008) provides: "cable total cross-sectional area and tray cross-sectional area ratio, power The cable should not be greater than 40%; control cable should not be greater than 50%. ". a variety of bending and accessories specifications should meet the engineering conditions and supporting the bridge. . support, hanger specifications of the choice, should be bridge specifications, layers, span and other conditions. And should meet the requirements of the load. . require the bridge fire section, must use steel or non-flammable, flame retardant materials. To select the bridge steps: . to determine the bridge width, layers, support the type and spacing, as well as the cable in the distribution of the bridge. . calculate the uniform load of each layer of cable (kN / m2), the initial determination of the bridge model, specifications. . according to the maximum cable total load load value to check the bridge strength
Cable bridge selection design . to determine the environmental conditions Environmental conditions are generally three: corrosive environment, the normal environment, special environment. . according to the majority of cable, in the room can be along the column, beam, floor walk, as far as possible in the process along the pipeline to go. . calculate the load calculation in the cable bridge to the cross section of the unit length of the cable weight q and the total load GG total = n1q1 + n2q2 ... ... nnqn where: q1 q2 q3 ... ... qn for each cable unit weight (kg / M) n1 · n2 · n3 ... nn is the same number of cables G total <G (the allowable load of the cable to the reference load curve chart) . select the bridge according to the cable load and bridge installation of the environment to the bridge Load curve as the basis, to determine the type of bridge and specifications and column spacing, the length of the arm, the bridge level, the length of the column and so on. . according to the cable to the installation and installation of the environment to determine the fixed way of the bridge; hanging, vertical, (these two forms can be used unilateral fixed or bilateral fixed), wall side and so on. . a variety of cables in the cable bridge on the level of arrangement and inter-layer distance. Cable bridge level arrangement is: weak control cable in the top, then the general control cable, low-voltage power cables, high-voltage power cables in order: the following table: This arrangement is conducive to shielding interference ventilation, heat and so on.
