Supports for cable trays should provide a strength and working load capacity sufficient to meet the load requirement of the cable systems.Horizontal and vertical tray supports should provide and adequate bearing surface for the tray and should provisions for hold- down clamps or fasteners. In addition, vertical tray supports should provide secure means of fastening cable trays to supports.
6.6 Support Locations
Horizontal cable tray straight sections should be supported at intervals not to exceed the support span for the appropriate NEMA Class Designations shown in Table 3-1. Unspliced straight sections should be used on all simple spans and on ends spans of continuous span runs. A support should be located within 2 feet (610mm) of each side of an expansion connector. Straight section lengths should be equal to or greater than the span length to ensure not more than one splice between supports.
6.6.2 Horizontal Cable Tray Fittings
Supports for horizontal tray fittings should be placed within 2 feet ( 610mm) of each fitting extremity, and as follows;
(a) 90- degree supports at the 45- degree point of arc
(b) 60- degree supports at the 30- degree point of arc
(c) 45- degree supports of the 22-1/2 degree point of arc ( except for the 12 inch [305] radii)
(d) 30 – degree supports at the 15- degree point of arc except for the 12- inch [305] radii)
Horizontal Tee Supports (See Figure 6-2)
Within 2 feet [610] of each of the three openings connected to other cable tray items for the 12-inch [305] radius. On all other radius at least one support should be placed under each side rail at the horizontal preferably as shown in Figure 6-2.
Horizontal cross supports (See Figure 6-3)
Within 2- feet [610] of each of the four openings connected to other cable tray items for the 12- inch [305] radius. On all other radii, at least one support should be placed under each side rail of the horizontal cross, preferable as shown in Figure 6.3.
