How to read loading curves

Instruction for interpretation of loading curves for cable ladders / trays / lighting tracks.

Above curves there is a five-hole loading beam (situation 1) where in openings A and E the deflection f1 is measured. In long installations the deflection is equal to the situation f2. In case the cable ladder end is firmly fastened to the wall of the starting point, deflection f2 shall be used. In case the cable ladder starts with no fastening to the wall and an uniformly distributed suspension is used, the deflection between openings A and E is at the point f1 and the deflections of other openings at the point f2. If the cable ladder is mounted freely without any end suspension and a lower deflection is required (situation 2), the interval between supports shall be reduced by 20%, i.e. 0,8 x L (L=equal distribution of supports), in which case the loading situation is equal to the situation 2. The maximum deflection of the situation 2 in each opening is presented in table 2.

Deflection is also effected by the quality of joints and the used supporting in relation to joint locations. Ending point of the loading lines tells the maximum loading (breakage reliability > = 2), which shall not be exceeded.