Ladder-type cable tray specifications table

Ladder-type cable trays are designed with side rails and transverse rungs to support and manage cables, available in various materials, widths, depths, and load ratings to meet mechanical and electrical standards.

Materials and Construction

Ladder cable trays are typically constructed from steel, stainless steel (304 or 316), or fiberglass reinforced plastic (FRP) depending on the application . Steel trays often feature 16-gauge tubular steel for side rails and rungs, while FRP trays use pultruded or molded composites with 45–65% glass fiber content for strength and UV resistance . All materials are designed to be fire retardant, with FRP trays achieving Class 1 flame spread ratings (≤25 per ASTM E-84) . Conductive resin systems may include carbon additives to dissipate static electricity.

Dimensions and Load Ratings

Ladder trays are available in various widths and depths to accommodate different cable bundles. Common nominal depths include 2” (51 mm), 3” (76 mm), 5” (127 mm), 7” (178 mm), and 9” (229 mm), . Rung spacing is typically 9.25 inches for FRP trays, while steel trays may vary depending on manufacturer specifications . Load capacity is defined by the Safe Working Load (SWL) and depends on the span between supports, with deflection measured at mid-span for single-span installations . Continuous spans may allow higher load ratings.

Fittings and Accessories

Ladder trays include straight sections, elbows, tees, reducers, and splice plates. Fittings are pre-drilled to accept connector plates and are designed to match the load-carrying capacity of straight sections . Connections between rungs and side rails use mechanical locks, adhesive bonding, or locking pins, ensuring structural integrity . Bolts and nuts are included for assembly, and all cut ends or drilled holes are resin-coated or treated to prevent corrosion in FRP trays.

Installation Guidelines

Ladder trays can be mounted on floors, walls, ceilings, or equipment racks . Supports must comply with span criteria to maintain load capacity. For steel trays, J-bolt kits or drilled holes may be used to secure trays to cabinets or racks . FRP trays require careful alignment of locking pins and adhesive bonding for fittings . The interior of the tray should remain free of sharp projections to prevent cable damage.

Compliance and Standards

Ladder cable trays conform to IEC 61537, NEMA VE 1, CSA E22.2 No. 126.1, and other international standards . CE marking or UL certification may apply depending on the region and manufacturer. Fire, UV, and chemical resistance are tested according to ASTM E-84 and other relevant standards .

Summary

Ladder-type cable trays provide robust mechanical support, strain relief, and cable management for electrical and data installations. Key specifications include material type, tray width and depth, rung spacing, load rating, fire and UV resistance, and compliance with international standards. Proper selection and installation ensure safe, durable, and efficient cable routing in industrial, commercial, and marine environments .