Steel cable trays undergo thermal expansion and contraction due to changes in ambient temperature. Outdoor cable trays are significantly affected by temperature; for instance, if the maximum ambient temperature is 40°C and the minimum is -20°C, the maximum contraction of the cable tray is calculated using the following formula:
Δt = 11.2 × 10⁻⁶ × 60°C × 1000 mm
This leads to the following conclusions:
For a temperature difference of 60°C, Δl = 0.672 mm/m
For a temperature difference of 50°C, Δl = 0.560 mm/m
For a temperature difference of 40°C, Δl = 0.448 mm/m
In engineering design, expansion joints should be incorporated into straight sections of cable trays, with the recommended spacing determined as follows:
50 m for a temperature difference of 40°C;
40 m for a temperature difference of 50°C;
