Calculate horizontal, vertical, or compound cable tray offsets based on bend angle, offset distance, and available installation space. Measure this distance along the straight tray. Hubbell Wiring Device-Kellems and Hubbell Premise Wiring are divisions of Hubbell Incorporated, a U. headquartered manufacturer with over 130 years of supplying solutions for the electrical and data markets. Hubbell's strength is demonstrated by a long-standing reputation for supplying reliable. 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. Cable tray supports are components used to fix and support. This guide covers the critical steps, from selecting the right electrical cable tray and performing accurate cable fill calculations to managing a safe cable pull through and ensuring all bonding and grounding requirements are met. Additional engineering factors must be considered to ensure safety, reliability.