DEFINITION

ConductorA material through which electric current fl ows easily - oft en referred to as wires.

DEFINITION

InsulatorsThe ceramic piece that holds the conductor to the structure.

Lightning and transmission structures

1-877-267-1453www.altalink.ca

CONTACT USAltaLink understands that landowners may be concerned about the possibility of lightning strikes on their property when hosti ng transmission structures.

Lightning strikesThe tallest object in a storm doesn’t always get struck by lightning. A lightning strike path is random and unpredictable, but lightning does tend to hit the tallest object, whether a house, a tree, or a transmission structure. AltaLink’s transmission structures are grounded, and if lightning strikes a grounded structure the energy is dispersed to ground.

Overhead Shield WiresAlmost all of AltaLink’s transmission structures are equipped with Overhead Shield Wires (OHSW) to protect equipment from lightning strikes. Much like the lightning needles on top of high-rise buildings, the OHSW protects the transmission lines by providing a safe path that leads the lightning energy to the ground.

The OHSW is placed on top of the transmission line so it is more likely to be struck by lightning than the energized conductor. The energy from a lightning strike would be dissipated along a number of diff erent structures in each directi on, and ulti mately to the ground.

If lightning strikes an energized conductor the insulators are designed so the energy will be directed towards a grounded structure. This energy would then be dissipated over a number of structures connected by the OHSW and would travel to the ground. A lightning strike to the energized conductor would cause the line to become de-energized.

SPRING/SUMMER 2012

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