Metal actually expands and contracts with weather change, and leaving some small gap in between tray sections is a must. When the distance between the metals is too low, the metals will push against each other and bend. The industry is. 1993 NEC Section 300-7 (b) states that “Raceways shall be provided with expansion joints where necessary to compensate for the thermal expansion or contraction. This subject. e tray system. This paper examines the causes, implications, and mitigation of thermal dynamic stress in metallic cable tray systems, focusing on thermal expansion and contraction, the resulting internal stresses, and potential damage to both the t ay and cables. We will not accept any warranty claims for damage caused hrough non-observance of these instructions safe y information ded, then dea inor injury o ystems support and route all types of cables. Please first log in with a verified email before subscribing to alerts.
