How to determine the specifications of metal cable trays

Metal cable trays are constructed from steel or aluminum, conforming to standards such as NEMA VE 1, ASTM, and IEC 61537, with specific requirements for material, finish, and structural integrity.

Types of Metal Cable Trays

Metal cable trays come in several types to suit different installation needs: Ladder type: Open design with side rails and rungs, ideal for heavy power cables and ventilation. Solid bottom type: Continuous base for full support, suitable for sensitive or small cables. Trough type: Partially ventilated, providing protection while allowing airflow.

Channel type: Simple U-shaped design for light-duty applications. Wire mesh trays: Flexible and lightweight, often used for data and communication cables.

Material Specifications

Aluminum trays: Side rails and rungs extruded from Aluminum Association Alloy 6063; fabricated parts from Alloy 5052. Steel trays: Structural quality steel, pre-galvanized per ASTM A653 SS, Grade 33, coating G90; hot-dip galvanized after fabrication per ASTM A123 for corrosion protection. Stainless steel: Used in corrosive environments for durability and chemical resistance.

Thickness options: Common gauges include 1. 0 mm, 1. 2 mm, 1.

5 mm, and 2. 0 mm depending on load requirements.

Construction and Accessories

Units must have rounded edges and smooth surfaces for safety and compliance. Splice plates, bolts, nuts, and washers are required for connecting sections. Covers for steel trays must be hot-dip galvanized; mill galvanized covers are not acceptable for hot-dip trays.

Fittings include bends, tees, elbows, drop-outs, and supports to accommodate routing. Standards and ComplianceNEMA VE 1: Defines manufacturing requirements, load/span classes, and types of metal trays.

AST

M standards: Include A123 (hot-dip galvanizing), A653 (zinc-coated steel), A1011/A1008 (steel sheet specifications), and B633 (electrodeposited zinc coatings),.

IE

C 61537: International standard for metal cable tray systems, including testing and performance requirements.

U

L 568: Covers performance requirements for safe application of fiberglass and metal trays. Local and international standards: Compliance with BS EN 61537, CENELEC EN 50173-1, EIA/ITA 568 A, ISO/IEC 11801-1: 2017 for cable management.

Installation Considerations

Trays must be installed according to load ratings and span classes specified by the manufacturer and standards. Proper support spacing, alignment, and grounding are essential for safety and performance. Maintenance and inspection are recommended, especially for hot-dip galvanized trays to remove excess zinc and ensure coating integrity.

Metal cable trays provide a versatile, durable, and code-compliant solution for routing electrical and communication cables, with material, type, and finish selected based on environmental conditions, load requirements, and regulatory standards.