Lightning protection

A wireless communications tower comprising an isolated power supply line for powering masthead electronic equipment situated at a first location from a power supply situated at a second location remote from the electronic equipment, wherein the first location has a first local around potential and the second location has a second local around potential, the first location being sufficiently remote from the second location that a lightning surge current may induce a difference between the first local ground potential and the second local ground potential, the difference in potential being of a magnitude so as to risk causing damage if it were applied to the electronic equipment,

• the isolated power supply line comprising a balanced differential power transmission path comprising two conductors connecting the power supply to the electronic equipment, the power supply being operable to provide a potential difference on each of the two conductors and the electronic equipment being operable to derive a potential difference between the two conductors, the tower further comprising at least one isolating transformer in the power supply line for providing isolation from the difference between the first and second local ground potentials associated with lightning surge currents, wherein the isolated power supply line is not connected to the first or second local ground potential so as to achieve isolation from ground potential rise associated with lightning surge currents, and an isolated data communications link between the masthead electronic equipment and a network terminal.

A method of powering electronic equipment situated at a first location over an isolated power supply line from a power supply situated at a second location remote from the electronic equipment, wherein the first location has a first local ground potential and the second location has a second local around potential, the first location being sufficiently remote from the second location that a lightning surge current may induce a difference between the first local around potential and the second local around potential, the difference in potential being of a magnitude so as to risk causing damage if it were applied to the electronic equipment,

• the method being for providing isolation from the difference between the first and second local ground potentials associated with lightning surge currents, comprising the steps of:
• a. providing a balanced differential power transmission path connecting the power supply to the electronic equipment, the path comprising two conductors;
• b. providing at least one isolating transformer in the power supply line;
• and
• c. supplying power from the power supply to the electronic equipment through the balanced differential power transmission path and the at least one isolating transformer by providing, at the power supply, a potential difference on each of the two conductors and deriving, at the electronic equipment, a potential difference between the two conductors,
• wherein the isolated power supply line is not connected to the first or second a local ground potential so as to achieve isolation from ground potential rise associated with lightning surge currents.