Standard Requirements for Cutting Mesh Cable Trays

Cutting mesh cable trays must comply with IEC 61537, NEMA VE 1, and manufacturer guidelines to ensure mechanical integrity, electrical continuity, and safety.

Material and Mechanical Considerations

Mesh cable trays are typically made from high-strength steel, stainless steel, or aluminum, with corrosion-resistant coatings or finishes depending on the environment . When cutting, it is essential to maintain the structural integrity of the tray, avoiding deformation of the mesh or weakening of load-bearing sections. Sharp edges should be deburrred to prevent cable damage and ensure safe handling . The tray must continue to meet load and span requirements as specified in IEC 61537 and NEMA VE 1 after any modification .

Electrical and Safety Requirements

Mesh cable trays often serve as part of the grounding or bonding system. Cutting should not compromise electrical continuity; any joints or cut ends must maintain a resistance of less than 0.1 ohms across connections if used for grounding . Additionally, trays must retain fire resistance and ventilation properties, ensuring proper cable cooling and preventing overheating .

Cutting Techniques and Tools

• Use appropriate cutting tools such as metal shears, angle grinders, or band saws designed for the tray material.
• Avoid excessive heat generation during cutting to prevent coating damage or warping.
• Ensure accurate measurement and marking to maintain proper alignment with bends, branches, or connectors .
• After cutting, edges should be smoothed and protective coatings reapplied if necessary to prevent corrosion .

Compliance and Documentation

All modifications, including cutting, should comply with:

• IEC 61537: International standard for metal cable tray systems, covering mechanical strength, corrosion resistance, electrical continuity, and installation compatibility .
• NEMA VE 1: North American standard specifying construction, load/span classes, and installation requirements for metal cable trays, including wire mesh types .
• Manufacturer-specific guidelines: Ensure that cutting does not void warranties or compromise product certification .

Best Practices

• Plan cuts to minimize the number of modifications and maintain tray integrity.
• Use connectors or splice plates to reinforce cut ends if necessary.
• Verify load ratings and span compliance after cutting.
• Maintain proper bend radius for cables exiting the tray to prevent damage .

By following these standards and best practices, mesh cable trays can be safely cut and installed while maintaining compliance with international and national electrical codes, ensuring both mechanical and electrical safety.