Composite cable tray specification code

Composite cable trays, typically fiberglass reinforced plastic (FRP), are specified according to material composition, fire rating, load capacity, and compliance with IEC 61537 standards.

Material and Manufacturing Requirements

Composite cable trays are generally made from fiberglass reinforced plastic (FRP) using pultrusion, compression molding, or resin transfer molding. The glass fiber content in pultruded components ranges from 45–65% by weight, while molded components range from 25–45% by weight. All materials include UV inhibitors to resist degradation and are fire retardant, achieving a Class 1 flame spread rating (≤25) per ASTM E-84. Conductive resin systems may include carbon additives to dissipate static electricity, meeting surface and volume resistivity requirements for specialized applications such as ABS-classed vessels .

Load and Span Specifications

The Safe Working Load (SWL) of composite cable trays must be declared by the manufacturer in accordance with IEC 61537, which defines load versus span relationships. Standard nominal tray depths include 2”, 3”, 5”, 7”, and 9” (51–229 mm). Load ratings are based on maximum deflection at mid-span for single-span installations, with continuous spans potentially allowing higher load ratings .

Standards and Codes

Composite cable trays are designed to comply with international and national standards, including:

• IEC 61537 – International standard for cable tray systems
• ASTM E-84 – Fire testing for surface spread of flame
• NEMA VE 1 & VE 2 – Guidelines for metallic and non-metallic cable tray systems
• ABS Rules – For installation on classed vessels or offshore facilities

Tray Configuration and Installation

FRP cable trays are available in ladder, trough, solid-bottom, and channel types, with straight sections, bends, tees, elbows, and drop-outs. Ladder-type trays consist of two longitudinal side rails connected by transverse rungs, providing high strength-to-weight ratio, corrosion resistance, and electrical insulation. Rung spacing is typically 150–230 mm (6–9 inches) for instrumentation and control applications .

Key Benefits of Composite Cable Trays

• Corrosion resistance superior to steel and aluminum
• Lightweight with high strength-to-weight ratio
• Non-conductive and impact resistant
• UV and chemical resistant, suitable for harsh industrial environments such as offshore platforms, chemical plants, and water treatment facilities In summary, the specification code for composite cable trays encompasses material composition, manufacturing method, fire and UV resistance, load capacity, and compliance with IEC 61537 and other relevant standards, ensuring safe and durable cable management in demanding environments.