Two Types of Wire for High Temperatures: XHHW vs. THHN
XHHW is an abbreviation for a kind of material used to make insulation for industrial and commercial types of wiring. It stands for cross-linked polyethylene (XLPE) that’s both high heat-resistant and water-resistant.
XHHW wire insulation is used on aluminum wire and copper wire. Sometimes called just XHHW wire, it’s ideal for wet locations as hot as 167 degrees Fahrenheit and dry locations up to 194 degrees Fahrenheit. XHHW-2 wire insulation is rated for both wet and dry locations up to 194 degrees Fahrenheit. The XHHW wire specifications enable its use in conduit and raceways for feeders and branch circuit wiring.
Another type of wire for high temperatures is thermoplastic high heat-resistant, nylon-coated wire (THHN). When comparing XHHW versus THHN wire, consider several points of contrast between the two. For example, XHHW has a polyethylene jacket, while THHN has a jacket of polyvinyl chloride (PVC). Also, THHN wire is thinner, so it’s not as protective as XHHW wire. And while both are excellent wires for high temperatures, only the XHHW wire is rated for both wet and dry use. THHN wire is less expensive, but XHHW is more efficient and lasts longer.
At Lowe’s, we offer XHHW wire by the foot or by the roll. Shop online to find the right wiring type for your construction project.