THWN stands for "Thermoplastic Heat and Water-resistant Nylon-coated." THWN is a designation for a specific insulation material, temperature rating, and condition of use (wet locations) for electrical wire and cable.
THWN stands for "Thermoplastic Heat and Water-resistant Nylon-coated." THWN is a designation for a specific insulation material, temperature rating, and condition of use (wet locations) for electrical wire and cable.