RHW-2 wire is still used for underground runs, but THWN-2 is a more common and versatile option.

RHW-2 (Resistant Heat and Water) Originally designed for underground use Moisture-resistant insulation Resistant to heat and cold temperatures Suitable for wet or dry locations Typically black or gray in colorTHWN-2 (Thermoplastic Heat and Water-Resistant Nylon) Can be used for both underground and above-ground runs Moisture-resistant insulation Resistant to heat, cold, and sunlight Suitable for wet or dry locations, including direct sunlight exposure Available in various colors, including white, black, and redComparison

THWN-2 is a more versatile option than RHW-2 because it can be used for both underground and above-ground runs. It also has a wider range of temperature ratings and is more resistant to sunlight exposure.In general, THWN-2 is the preferred choice for most electrical applications, including underground runs. However, RHW-2 may still be specified for specific underground installations where its moisture-resistant properties are required. Flag for review