CT Wire – Cable Tray, or CT wire, is a single conductor wire that is size 1/0 or bigger. Cu Conductor – Copper conductors, sometimes seen written as Cu conductors, are the standard wires used in electrical applications. Copper is more conductive than aluminum, stronger, and can better adapt to. Are you talking about "TC" cable? Anyway, Type MV cable can be run in tray. Check out Article 392 for more info. There are all kinds of things that can be run in cable tray in addition to TC cable. Does the NEC apply. The purpose of a cable tray system is to support, route, and protect cable as part of the cable management system. MAN-3 Why Cable Tray? Safety.