Cable tray support positioning holes

Cable tray support holes are typically pre-punched along the side rails and rungs, positioned to allow secure attachment to support brackets, with spacing determined by tray type, load, and manufacturer guidelines.Pre-Punched Holes and Support LocationsCable trays often feature pre-punched holes on the I-beam side rails and rungs to facilitate attachment of support brackets, accessories, and splice plates without additional drilling . These holes are strategically located to allow:Attachment of support elements such as wall brackets, ceiling trapeze hangers, or cantilever supports.Connection of splice plates between tray sections.Mounting of accessories like junction boxes or device supports. For solid-bottom trays, additional weep holes may be drilled at the sides and center every 3 feet to prevent water accumulation .Recommended Support SpacingStraight horizontal runs: Supports should be placed at intervals according to the manufacturer's load capacity chart, typically every 1.5 to 3 meters (5–10 feet) depending on tray type and cable weight .Connectors between tray sections: Position connectors between the support point and the quarter-point of the span, avoiding the center of the span or directly on supports .Elbows and bends: Additional supports are required near changes in direction to maintain mechanical stability .Expansion joints: Provide expansion connectors at building expansion joints or long outdoor runs (approximately every 30 meters or 100 feet) with bonding jumpers for electrical continuity .Installation NotesUse guides that allow longitudinal movement to accommodate thermal expansion and contraction .Ensure all trays are bonded together and grounded at least every 15 meters (50 feet) and at both ends .Pre-punched holes simplify installation and reduce the need for on-site drilling, improving efficiency and safety . By following these guidelines, cable trays can be securely supported, maintain proper alignment, and comply with electrical and mechanical standards.