How to use hollow polymer cable trays

Hollow polymer cable trays (FRP) should be installed with proper support, spacing, and cable securing to ensure structural integrity, compliance with standards, and long-term reliability.

Material Handling and Inspection

All hollow polymer trays and accessories must be inspected upon receipt for damage, conformity to specifications, and proper labeling. Store trays horizontally on a flat surface with timber supports at intervals of about one meter, protecting them from direct sunlight and moisture to prevent warping or degradation . Any damaged or non-compliant materials should be removed from the site immediately.

Support and Mounting

Hollow polymer trays are self-supporting but require secure attachment to structural elements. They can be mounted on steel structures, concrete surfaces, or dedicated supports using brackets, clamps, or self-drilling fasteners. Support spacing typically ranges from 2 to 3 meters, depending on tray type and load, with ladder-type trays allowing slightly longer spans than perforated or solid trays . Ensure that the supports are level to maintain a flat tray installation, which is preferred for ease of cable laying and maintenance.

Tray Layout and Routing

Install trays flat whenever possible, running under floors, walkways, or along walls. Vertical or edgewise installations are allowed only in special cases, with cables secured individually using stainless steel straps or polymer ties . Maintain clearances for maintenance access, typically at least 12 inches above the tray, and avoid prohibited areas such as hoistways or enclosed spaces . Plan the layout according to approved shop drawings, considering future expansion by leaving 20–50% of tray capacity unused .

Cable Securing and Fill

Cables should be grouped and tied at regular intervals: for horizontal trays, one tie every 2–3 meters; for vertical trays, two ties per meter . Observe fill limits: power cables should not exceed 40% of the tray cross-sectional area, and control or instrumentation cables should not exceed 50% . Ladder or ventilated trays are preferred for heat dissipation, while solid-bottom trays are suitable for low-heat applications or aesthetic requirements .

Environmental Considerations

Hollow polymer trays are corrosion-resistant and suitable for harsh environments, including chemical plants, coastal areas, or high-humidity locations. Ensure that the selected polymer material (e.g., FRP with polyester or vinyl ester resin) meets mechanical strength and fire-retardant requirements for the project . Avoid exposure to excessive UV without protective coatings, as prolonged sunlight can degrade some polymer resins.

Compliance and Safety

Follow NEC Article 392, NEMA VE1/VE2, or project-specific standards for grounding, bonding, and cable separation to prevent electromagnetic interference and ensure safety . Hollow polymer trays are non-conductive, so grounding is not required for the tray itself, but proper cable grounding must still be maintained. Ensure that the installation can support the design load, typically around 100 kg/m for industrial applications . By adhering to these guidelines, hollow polymer cable trays can provide a durable, safe, and maintainable cable management system suitable for industrial, commercial, and instrumentation applications.