Before selecting a cable tray, consider the following key factors: Cable Type and Volume: Determine the number and type of cables to be supported. Environmental Conditions: Assess indoor or outdoor usage, exposure to moisture, chemicals, or extreme temperatures. Cable tray systems are engineered support structures designed to route, support, and protect insulated electrical cables used for power distribution, control, instrumentation, and communication. What is Cable Tray? A cable tray is a unit, or set of units. In this guide, we explain what cable trays are, the main types available, how to choose the correct size and duty rating, and what to consider when designing a cable tray installation.