This specification describes single conductor THWN or THHN, a general purpose building wire insulated with polyvinyl chloride (PVC) and covered with a tough protective sheath of nylon intended for lighting and power circuits at 600 Volts or less, in residential, commercial and industrial buildings. The wire may be operated at 90°C maximum continuous temperature in dry locations and 75°C in wet locations .
THHN/THWN Wire Application
THHN wires are a widely used electrical wire type used in industrial, commercial and residential constructions and applications. Thes wires offer a host of benefits in comparison to other wire types. THHN building wire may also be used for wiring of machine tools, control circuits or on certain appliances.
THHN/THWN Wire Application Standard