GENERAL Type AC cables are constructed in accordance with the National Electrical Code? (NEC) and comply with the safety requirements of UL 4@ Standard for Armored Cable. These cables employ copper@ copper-clad@ or acceptable aluminum alloy conductors. Copper conductors are of sizes 14-1 AWG. Aluminum or copper-clad aluminum conductors are of sizes 12-1 AWG. All conductors 6-1 AWG are stranded. The NEC recognizes three AC cable types: ACHH@ ACTH@ and ACTHH. Type ACTHH is the most common of these. National Electrical Code? and NEC are registered trademarks of the National Fire Protection Association@ Inc.@ Quincy@ MA 02269.