Cable trays are designed to support a variety of electrical cables, including power, communication, and control cables. All materials expand and contract due to temperature changes. It is important that cable tray installations incorporate features which provide adequate compensation for their thermal contraction and expansion. In this guide, the expansion gaps are explained to be calculated, as well as how to select materials such as aluminum or steel. We aim to ensure your project remains secure and does not breach the NEMA standards, causing it to suffer. Steel cable trays, like all metallic structures, undergo dimensional changes when subjected to ambient temperature variations.