This step‑by‑step approach helps you determine width, depth, support spacing, and allowable load with confidence. Plan 20–30% spare capacity for growth. Remember separation rules for EMI. OBO BETTERMANN has offered prod-ucts and solutions for electrical instal-lation for over 100 years. With our many years of experience, we are one of the leading manufacturers in this field. Establishing partnerships. This publication is intended as a practical guide for the proper and safe* installation of cable ladder systems, cable tray systems, channel support systems and associated supports. The following pages address the 2014 National Electrical Code® requirements for cable tray systems as well as design. Cable tray support quantity can be calculated using a simple formula: Support Quantity = Total Length ÷ Support Spacing + 1 20 ÷ 2 + 1 = 11 supports In a typical project, a 20-meter cable tray with 2-meter spacing requires 11 supports. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned. Hubbell's NEXTFRAME® Ladder Tray is the effective and widely used cable runway that supports and delivers bundles of cable between cabinets, racks, and closets, along walls, and suspended from ceilings. The Ladder Tray features light, rugged, tubular steel construction.