Connection requirements for each section of cable tray

Proper connection of cable tray sections requires mechanical joining, grounding/bonding, and compliance with NEC Article 392 and manufacturer specifications.Mechanical ConnectionsEach section of a cable tray—whether ladder, trough, solid bottom, or channel—must be securely joined using splice plates, bolts, or clamps provided by the manufacturer. Splice plates are typically used to connect straight sections, bends, tees, and elbows, ensuring structural integrity and alignment of the tray system . Expansion joints may be required in long runs to accommodate thermal expansion and contraction. Supports such as brackets, hanger rods, or wall mounts must be installed at intervals specified by the tray type and load, generally following NEC and NEMA VE 2 guidelines .Electrical Bonding and GroundingMetallic cable trays must be bonded and grounded to prevent electrical hazards. This involves connecting each tray section electrically using bonding jumpers or integrated bonding lugs to maintain continuity throughout the system . Non-metallic trays, such as fiberglass-reinforced plastic (FRP), are non-conductive and do not require grounding but must be supported according to mechanical specifications . Proper bonding ensures safety and compliance with NEC Article 392.Cable Management and Fill ConsiderationsWhen connecting sections, ensure adequate spacing and support for cables to prevent sagging, overheating, or physical damage. Ladder trays provide rungs for tying cables, while ventilated troughs offer continuous support for smaller instrumentation cables . Tray fill limits must be calculated to avoid overcrowding, and power and data cables should be separated to prevent interference . Solid bottom trays may require additional support for heavy cable loads.Material and Environmental ConsiderationsConnection hardware and methods may vary depending on tray material. Aluminum trays require corrosion-resistant fasteners, while galvanized steel trays follow ASTM A123 or A653 standards for coatings . In corrosive or high-moisture environments, FRP trays are preferred, and connections must be compatible with the material to maintain structural integrity .SummaryTo ensure a safe and compliant cable tray system:Use splice plates, bolts, or clamps for mechanical connections.Maintain support spacing according to tray type and load.Ensure continuous electrical bonding for metallic trays.Respect tray fill limits and cable separation requirements.Select hardware compatible with tray material and environmental conditions.Follow NEC Article 392, NEMA VE 1/VE 2, and manufacturer guidelines for all connections . These practices ensure structural stability, electrical safety, and long-term reliability of the cable tray system.