This specification covers a crosslinked polyethylene insulation for electrical wires and cables for conductor sizes 8 AWG (8.37 mm2) and larger. The base polymer of this insulation consists substantially of polyethylene. The partial discharge, ac voltage, insulation resistance, and dc voltage shall be tested to meet the requirements prescribed. The accelerated water absorption, permittivity and dissipation factor, U-bend discharge, and surface resistivity shall be tested to meet the requirements prescribed. The heat distortion, and percent hot creep and percent hot set shall be tested to meet the requirements prescribed.