Cable quantity at cable tray bends

Yes, bends in a cable tray are included in the total quantity of the cable tray system.

Detailed Explanation

Cable tray systems are defined to include straight sections, bends, elbows, tees, drop-outs, supports, and accessories as part of the complete installation package. This means that when calculating the total quantity of cable tray required for a project, all bends and fittings are considered integral components and are included in the measurement of the system.

Measurement Considerations

Arc Length of Bends: The physical length of a bend is measured along the centerline of the tray, known as the arc length, which accounts for the curvature of the tray. This ensures that the linear footage of the tray includes the actual material used in bends. Centerline Radius: Manufacturers provide standard centerline radii for elbows and bends, which are used to calculate the arc length and ensure proper cable installation without exceeding minimum bend radii.

Integral Connectors: Many cable tray systems, such as those from Metsec, include connectors for bends, tees, and other fittings as part of the system, further confirming that these elements are counted in the total quantity.

Practical Implications

Including bends in the quantity ensures accurate material estimation, cost calculation, and installation planning. It also helps maintain compliance with standards such as NEMA VE-1 and NEC Article 392, which govern cable tray design and installation. In summary, when performing a quantity takeoff for cable trays, all bends, elbows, and related fittings are included in the total linear measurement of the tray system, and they should not be treated as separate items unless specifically required by project specifications.