| Cable Type and Quantity | Cable insulation, outside diameter, quantity, weight, voltage level, and whether power and communication cables share the route. | Select a tray with sufficient usable width and separation features for the cable arrangement. Keep power, control, and data cables separated when required by the design or applicable code. | Power cables Control cables Data cables Cable quantity and outside diameter should be based on the actual cable schedule, not nominal cable size. | Prepare a cable schedule, calculate the total cable cross-sectional area, and confirm the required segregation method with the electrical engineer. |
| Required Tray Width | Total cable occupancy, future expansion allowance, and the arrangement of single-layer or multi-layer cables. | Choose the next available tray width above the calculated requirement. Avoid filling the tray to its physical edge because installation, heat dissipation, and future maintenance require working space. | Common nominal widths include 150, 300, 450, 600, 750, and 900 mm. The final width depends on the cable layout and applicable fill limits. | Calculate the usable internal width, confirm the manufacturer’s fill recommendation, and include a documented spare-capacity allowance where required. |
| Load Capacity | Cable weight per metre, tray self-weight, covers, accessories, ice or dust accumulation, and any external loads. | The selected tray must have a published load rating greater than the calculated service load. Use the load rating for the actual support span and installation orientation. | Service load is commonly expressed as kg/m or N/m. A typical industrial design may use approximately 75–150 kg/m, but the project calculation controls. | Compare the calculated load with the tested load table for the exact tray width, material, side-rail height, and support span. |
| Support Span | Distance between brackets or hangers, structural layout, access restrictions, and seismic requirements. | Shorter spans generally increase load capacity and reduce deflection. Do not use a load rating from a longer or shorter span without confirming its applicability. | Common support spacing is approximately 1.5–3.0 m. Heavy-duty or seismic installations may require closer spacing. | Coordinate tray supports with the building structure and verify allowable deflection, connection strength, and seismic bracing requirements. |
| Tray Configuration | Cable access, cable type, ventilation needs, route geometry, and the number of bends, tees, and risers. | Use ladder tray for high ventilation and easy cable access, perforated or ventilated tray for general-purpose routing, and solid-bottom tray where additional cable support or protection is needed. | Ladder tray Perforated tray Solid-bottom tray Select fittings with a bend radius suitable for the largest cable. | Review the complete route drawing, including horizontal bends, vertical bends, tees, reducers, drops, covers, and expansion joints. |
| Material and Corrosion Exposure | Indoor or outdoor location, humidity, condensation, salt spray, chemicals, pollution, and washdown conditions. | Choose the steel finish according to the corrosivity of the environment. A protective metallic coating is commonly used for general service, while more robust coatings or stainless steel may be needed for severe exposure. | Pre-galvanized steel Hot-dip galvanized steel Stainless steel Coating selection must match the site environment and expected service life. | Obtain the coating type, coating thickness or mass, salt-spray or corrosion data where relevant, and compatibility information for the installation environment. |
| Temperature and Thermal Management | Ambient temperature, cable operating temperature, solar exposure, heat sources, and cable grouping. | Use a ventilated tray where heat dissipation is important. Confirm the cable ampacity after applying grouping, ambient-temperature, and installation-method correction factors. | Outdoor solar exposure can increase tray and cable temperature. Cable ampacity must be calculated using the applicable electrical standard and actual installation conditions. | Have the electrical designer verify ampacity, cable spacing, ventilation, and any temperature derating before finalizing the tray arrangement. |
| Electrical Bonding and Earthing | Continuity across tray joints, protective bonding, fault-current requirements, and local electrical regulations. | Provide bonding jumpers or approved bonding hardware where required. Tray sections should not be assumed to provide electrical continuity unless the system has been evaluated for that purpose. | Bonding requirements depend on the electrical system, fault level, joint design, and governing code. | Confirm joint resistance, bonding hardware, conductor sizing, and connection to the site earthing system with the responsible electrical engineer. |
| Mechanical Protection | Risk of falling objects, impact, unauthorized access, water entry, dust, and maintenance activities. | Use covers, reinforced side rails, or a more protective tray arrangement where cables are exposed to impact, falling debris, water, or high contamination. | Ventilated cover Solid cover Reinforced tray The protection level should reflect the actual site hazards. | Perform a route hazard review and verify cover fastening, drainage, impact resistance, and access requirements. |
| Fire and Smoke Requirements | Fire compartmentation, fire-rated routes, emergency systems, cable function during fire, and building regulations. | Steel tray is non-combustible, but the complete installation may still require fire stopping, fire-rated supports, protected penetrations, or dedicated fire-survivability systems. | Fire requirements vary by building type, cable function, authority requirements, and project specifications. | Coordinate tray penetrations, fire stopping, support details, and emergency-circuit requirements with the fire-protection and electrical designs. |
| Dimensional Compatibility | Tray width, side-rail height, splice-plate position, fitting geometry, cable bend radius, and available clearance. | Select dimensions that accommodate the largest cable bend radius and maintain clearance from walls, pipes, ducts, doors, and other services. | Common side-rail heights are approximately 50–150 mm. Required bend radius is determined by the cable manufacturer and cable construction. | Overlay the tray route on the coordinated services model and confirm access for cable pulling, inspection, and future replacement. |
| Installation and Maintenance | Site access, lifting limitations, installation tools, cable pulling method, inspection access, and replacement strategy. | Choose manageable section lengths and accessible joint locations. Provide adequate clearance above and beside the tray for pulling, inspection, and maintenance. | Section lengths are commonly selected according to site handling capacity and route conditions rather than a single universal standard. | Review installation sequence, lifting method, joint access, cover removal, cable pulling tension, and planned maintenance procedures. |
| Standards and Testing | Applicable national and project standards, load testing, deflection limits, corrosion documentation, and quality records. | Specify a tray system that has documented performance data for load, deflection, electrical continuity where applicable, and material or coating properties. | Common references may include IEC 61537 or an applicable national equivalent. The project specification and local regulations take precedence. | Request technical drawings, load tables, material certificates, coating records, installation instructions, and test documentation. |
| Future Expansion | Expected additional circuits, spare capacity, future route changes, and plant expansion plans. | Reserve practical capacity without creating excessive cost or unnecessary obstruction. Consider spare width, additional support capacity, and accessible route sections. | A project may reserve approximately 20–30% additional space when permitted by the design basis, although the required allowance is project-specific. | Document the spare-capacity assumption and verify that supports, fittings, and cable separation remain adequate after expansion. |
| Total Installed Cost | Tray sections, fittings, covers, supports, bonding, coatings, transport, installation labor, and maintenance. | Compare complete installed-system cost rather than the price of straight tray sections alone. A durable finish and efficient installation can reduce lifecycle cost. | Cost drivers include material thickness, finish, width, support spacing, fitting quantity, access difficulty, and corrosion exposure. | Request a bill of materials and lifecycle-cost comparison covering tray, fittings, supports, installation, inspection, and replacement requirements. |