NEMA Standards Publication VE 1 also provides specific recommendations regarding the installation of expansion joints in cable tray systems. This subject. , is a welded wire-mesh cable management system made of high-strength steel wire. It is used to manage cables for light B manufactures its cable tray in a range of materials with a variety of finishes. The selection of material and finish is a function of the environment in wh tant in a wide range. Cable tray systems, essential for supporting electrical cables, are subject to thermal expansion and contraction due to temperature fluctuations. As cables and trays expand or contract, they can cause stress on the structure, leading to potential damage or misalignment. Cable trays have no space to flex, and may bend or break bolts.