Single conductor cables and Type MV cables must be installed in ladder or ventilated trough cable trays. While they may seem similar at first glance, both systems serve different purposes and have distinct characteristics. Understanding the difference between a cable ladder and cable tray is essential for selecting the right. The cable tray types to choose from are ladder, ventilated trough, or solid bottom. For a few types of. Cable tray systems are engineered support structures designed to route, support, and protect insulated electrical cables used for power distribution, control, instrumentation, and communication.