Ask the Wire Experts:
THHN vs XHHW-2

FACTORS THAT SET XHHW-2 APART FROM THHN

Thermoplastic and thermoset are two types of cable insulations commonly used for single conductors. It’s important to understand their strengths and weaknesses when designing and building a new facility, machine, or appliance.

THERMOPLASTIC INSULATION

THHN/THWN-2 is a thermoplastic product. It uses a thinner PVC insulation, which can lead to current leakage and dielectric breakdown in demanding circuits or from chemical or environmental exposure. The PVC insulation in THHN/THWN-2 emits a toxic smoke when burned and is less flexible at cold temperatures. However, it is lighter in weight and less expensive to manufacture.

Thermoplastic compounds can be heated, then shaped and cooled to maintain their desired shape. This process can typically be repeated by applying heat to remelt the insulation, which can lead to potential danger in some applications.

Examples of thermoplastic compounds include:

THERMOSET INSULATION

XHHW-2 is a thermoset product. Crosslink products like XHHW-2 have XLPE (crosslinked polyethylene) insulation instead of PVC. XLPE is more resistant to chemicals, ozone, and abrasions. Because of the chemistries involved, modern XLPE is far less toxic than PVC in the event of fire. In most applications, thermosets are more flexible than thermoplastics and are more advantageous for projects where complex, close-spaced bends are required.

Thermoset compounds utilize a curing process which causes a chemical reaction, allowing the polymers to cross-link. Once cured, the thermoset insulation retain their shape and will not remelt when heat is applied.

Examples of thermoset compounds include:

XLPE INSULATED CONDUCTORS

Service Wire is now stocking ServicePRO-X^® cross-linked single conductors in XHHW-2, RW90, USE-2, and RHW-2.

ServicePRO-X^® single conductors are insulated with thermoset cross-linked insulation.

These products use XLPE instead of PVC, are dual rated 600V/1kV, and are Hospital Grade.

Plus, ServicePRO-X^® single conductors don't require pulling lubricant and need less pulling force during installation. Available in a full range of true industry standard colors for fast and easy phase ID.