THHN

THHN is an alphabetism or initialism which stands for "Thermoplastic High Heat-resistant Nylon-coated." [ [http://www.acronymfinder.com/acronym.aspx?rec={8E86B062-89E8-11D4-8351-00C04FC2C2BF What does THHN stand for? Acronym Finder Definition ] ] 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. [NFPA 70 National Electrical Code (NEC) 2008 edition, Article 310.8 (B)&(C), Table 310.13(A)]

Wires with THHN insulation are commonly used in the alternating current (AC) electrical distribution systems of buildings 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 [ NFPA 70 National Electrical Code (NEC) 2008 edition, Article 310.14 ] which are either solid or stranded, depending on size.

THHN electrical conductor insulation is governed by the following Industry Standards:
• UL 83 - File No. E15119
• UL 1063 (MTW) - File No. E85964
• AWM - File No. E11829
• Canadian Standard C22.2 No. 75 and CSA Bulletin No. 1451
• ASTM: B3, B8, B787
• WC70/ICEA S-95-658
• U.S. Federal Specification A-A-59544

For more information on this type of insulation, see:
*Electrical wiring

ee also

*THWN

References

External links

* [http://www.alanwire.com/awscripts/makspecs.cgi?ntype=THHN Example of a website using the THHN designation]