THHN stands for "
Thermoplastic
High
Heat-resistant
Nylon-coated."
[20] THHN is a designation for a specific
insulation material, temperature
rating, and condition of use (suitable for dry and damp locations) for electrical
wire and
cable.
[21]
Wire with
THHN insulation is commonly used in the
alternating current (AC) electrical distribution systems of all types and sizes throughout North America, usually at
voltage levels (
potential difference or electromotive force) ranging from 110-600 volts. This type of
insulation is used for both copper and aluminum conductors
[22] which are either solid or stranded, depending on size.
