A method of performing line insulation monitoring of a pair of conductor lines at least partially located in a cable, comprising the steps of: a) providing a first power switch in a first conductor line of the pair and a second power switch in a second conductor line of the pair, b) providing a line insulation monitor at a first end of the pair of conductor lines, electrically connected to the pair of conductor lines, c) at the second end of the pair of conductor lines, electrically connecting the first and second conductor lines, d) placing the first and second power switches into a monitoring configuration wherein the first power switch is closed while the second power switch is open, and e) using the line insulation monitor to monitor the insulation of the conductor lines.