THHN Wire

THHN (Thermoplastic High Heat-resistant Nylon) wire consists of a stranded or solid, bare copper or aluminum conductor with a thermoplastic insulation and a nylon jacket. THHN building wire is ideal for use in appliances, machine tools and control circuit wiring. Type THHN is suitable for use in dry locations with temperatures not exceeding 90 degrees Celsius.
THWN (Thermoplastic Heat and Wet-resistant Nylon) wire is similar to THHN, with the added benefit of moisture-resistance. This allows THWN to be used without conduit, however, the heat-resistance is not as high as THHN. THWN should only be used in locations that won’t exceed 75 degrees Celsius.
THWN-2 wire is similar to THWN, with the added benefit of greater heat-resistance. THWN-2 can be used in both wet and dry locations with temperatures up to 90 degrees Celsius.
THHN vs MTW: THHN consists of a stranded or solid, bare copper or aluminum conductor with a thermoplastic insulation and a nylon jacket. MTW consists of stranded, bare copper conductors insulated with polyvinyl chloride (PVC). Although both MTW and THHN are well suited for similar applications, THHN wire’s nylon jacket causes it to be less flexible than MTW wire.
FAQ
What is THHN wire?
THHN is a thermoplastic high-heat-resistant, nylon-coated wire. It is dual rated for use in both indoor and outdoor and wet and dry conditions. It can be handle up to 600v.
What is THHN wire used for?
THHN is very popular as an inexpensive building wire. It can be used anywhere from lighting commercial buildings to appliances, machine tools and control circuits.