Learn how to manage thermal expansion and contraction in cable tray systems with expert tips on expansion joints, guides, and spacing to ensure long-term structural integrity. This subject is addressed in the NEMA Standards Publication No. VE 1 “Metallic Cable Tray Systems” Section 6. The Cable Tray ng standards, performance standards, test standards and application in this document have been tested extens ompetent professional en completely installed, without damage either to conductors or. Steel cable trays, like all metallic structures, undergo dimensional changes when subjected to ambient temperature variations. Cable trays have no space to flex, and may bend or break bolts. We aim to ensure your project remains secure and does. Owner: Richmond, David Product Areas: Cable Tray Divisions: BI - Building Infrastructure ESPG Category: Wire & Cable Description: All materials expand and contract due to temperature changes.