Specifications of cable tray bevel joints

Cable tray bevel joints are typically connected using bolted splice plates, with dimensions and specifications defined by tray width, material, and load requirements.Joint ConfigurationBevel joints in cable trays are usually formed by cutting the tray ends at an angle to allow smooth directional changes or transitions. These joints are reinforced using splice plates that are bolted to the tray side rails. The splice plates ensure mechanical strength, electrical continuity, and alignment between adjacent tray sections.Splice Plate Dimensions and BoltingMaterial: High-strength steel, typically ASTM A1011 HSLAS, Grade 50, Class 1, or equivalent, to match the tray's mechanical properties .Bolt Pattern: Standard splice plates use 8 bolts per plate for ladder-type trays, with serrated flange locknuts to prevent loosening .Plate Size: The splice plate width and length are generally proportional to the tray width; for example, a 12-inch tray may use a plate approximately 4–6 inches wide and extending along the side rails to cover the bevel joint. Exact dimensions depend on manufacturer specifications and tray series .Electrical Resistance: Fixed splice connections are designed to maintain a resistance not exceeding 0.00033 ohms, ensuring proper grounding continuity .Material and CoatingGalvanized Steel: Sendzimir galvanized steel (Z275, 275 g/m²) is commonly used, providing corrosion protection and cathodic action if the coating is breached .Aluminum or Stainless Steel: Used in corrosive environments or where lighter weight is required .Optional Coatings: Powder or epoxy coatings may be applied for additional chemical resistance .Installation ConsiderationsRung Spacing: For ladder trays, maintain 6–12 inches spacing depending on cable type and load .Alignment: Ensure the bevel joint aligns with the tray's centerline to prevent cable stress.Support: Bevel joints should be supported at intervals consistent with the tray's span rating, typically every 6–12 feet for indoor installations .Load Capacity: Verify that the splice plate and joint configuration can support the maximum cable load, including environmental factors like wind or snow for outdoor installations .SummaryCable tray bevel joints rely on bolted splice plates to maintain structural integrity and electrical continuity. The dimensions of the splice plates and bolt patterns are determined by tray width, material, and load requirements. Proper material selection, corrosion protection, and installation practices are essential to ensure long-term performance and compliance with standards such as NEMA VE 1 and UL 568 .