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. Follow these simple steps: Define Tray Dimensions: Enter the width and depth of your planned cable tray (in mm or inches). Select Fill Standard: Choose 40% for power cables (NEC compliant) or 50% for. 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. Stop Costly Cable Tray Installation Errors Now: Avoiding Mistakes in Instrumentation Cable Tray Installation: A Guide for EPC Projects Cable tray sizing in real EPC projects is not limited to simple area calculation. Additional engineering factors must be considered to ensure safety, reliability. Cable Information: Location: Engineer: #/Cond. Sum Area (in^2) Comments Maximum allowable tray fill per Area (in^2) Tray Design Depth = Sum of OD (in) Total Cross Sectional Areas of all cables: Total Sum of the Diameters: in. ST AL Rn ENGrNEERING RuiDBOOK IETHODS. sensitivity studies included for confidence. alternate calculation ba3 been.