XHHW

XHHW is an alphabetism or initialism which stands for "XLPE (cross-linked polyethylene) High Heat-resistant Water-resistant."^[1] XHHW is a designation for a specific insulation material, temperature rating, and condition of use (suitable for wet locations) for electrical wire and cable.^[2]

Wires with XHHW insulation are commonly used in the alternating current (AC) electrical distribution systems of commercial, institutional, and industrial buildings and installations, 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 ^[3] which are either solid or stranded, depending on size.

According to Underwriters Laboratories (UL) Standard 44^[4], XHHW insulation is suitable for use in dry locations up to 90° C (194° F), or wet locations up to 75° C (167° F).

XHHW-2 insulation, which is similar to XHHW, is suitable for use in dry or wet locations up to 90° C (194° F).

XHHW / XHHW-2 electrical conductor insulation is governed by the following Industry Standards:
• UL 44 - File No. E63539
• CSA LL 82214
• ASTM-B3
• ASTM-B8
• ASTM-B787
• U.S. Federal Specification A-A-59544
• NEMA WC70/ICEA S-95-658

For more information on this type of insulation, see:

• Electrical wiring

References

1. ^ What does XHHW stand for? Acronym Finder Definition
2. ^ NFPA 70 National Electrical Code (NEC) 2008 edition, Article 310.8 (B)&(C), Table 310.13(A)
3. ^ NFPA 70 National Electrical Code (NEC) 2008 edition, Article 310.14
4. ^ Scope for UL 44