Thermal Expansion and Contraction of Cable Tray

Thermal Expansion and Contraction of Cable Tray:

  • A cable tray system may be affected by thermal expansion and contraction, which must be taken into account during installation.
  • To determine the number of expansion splice plates you need, decide the length of the straight cable tray runs and the total difference between the minimum winter and maximum summer temperatures.
  • To function properly, expansion splice plates require accurate gap settings between trays.
  • The support nearest the midpoint between expansion splice plates should be anchored, allowing the tray longitudinal movement in both directions.
  • When a cable tray system is used as an equipment grounding conductor, it is important to use bonding jumpers at all expansion connections to keep the electrical circuit continuous.


Temperature Differential (oF) Steel (Feet) Aluminum(Feet)
25 512 260
50 256 132
75 170 86
100 130 65
125 102 54
150 86 43
175 73 37