The types of cables, allowed in cable trays, and the wiring methods permitted in cable trays can be found in NEC Section 392. In general, tray rated cables are quality products that have been tested to withstand the rigors. Understanding the different types of low voltage cables helps you choose the right one for your project — ensuring safety, efficiency, and reliable performance. Our experienced low voltage wiring contractors in San Jose specialize in designing and installing safe, efficient cabling systems for both. Cable tray systems are engineered support structures designed to route, support, and protect insulated electrical cables used for power distribution, control, instrumentation, and communication.