Provides technical requirements concerning the construction, testing, and performance of metal cable tray systems. association representing the major electrical equipment manufac-turers in the U. Addresses shipping. Cable tray (or cable ladder) systems are a popular alternative to electrical conduit systems, as they have an outstanding record for dependable service, design flexibility and cost savings in commercial and industrial applications. A properly designed and installed cable tray system will provide. Hubbell Wiring Device-Kellems and Hubbell Premise Wiring are divisions of Hubbell Incorporated, a U. Hubbell's strength is demonstrated by a long-standing reputation for supplying reliable. This article provides a comprehensive framework that governs various aspects of cable tray installations, including the types of cables that are deemed acceptable for use, requirements for grounding and bonding, and stipulations regarding tray fill capacity. Here's what you need to know: Cable Types: Only use.