XHHW Wire Preferred by Many Electrical Contractors Verse THHN Wire

The key difference between the two building wires is XHHW utilizes cross-linked polyethylene (XPLE) and THHN uses a poly-vinyl chloride (PVC) as the insulation over the conductor. XHHW performs better in the low temperature environments and has a higher K Value, or better electrical properties.

“We continue to see more and more customers request XHHW over THHN now that copper prices have dropped again. XHHW has better current carrying capacity giving it the ability to withstand meltdown better, and even with its marginal price increase, many customers make it their choice over THNN,” remarked Bryce Huett, President of Distributor Wire & Cable in Denver, Colorado.

XHHW typically cost 10-20% more than THHN but that gap is closing as cross-linked polyethylene becomes more and more available. It is worth noting that the nylon coating on THHN wire makes it stiffer than its building wire counter part. Installers always prefer a more pliable product when trying to pull their runs throughout a structure.