Fence wires that are mounted on wood posts can build up an electrical charge near power lines. Important factors are:
- Length of fence paralleling the line
- Distance between the line and the fence
- Amount of moisture in the fence posts and the ground
Presence of grounding devices such as metal fence posts or weeds growing next to the fence
What do I need to know about non-electric fences?
Non-electric fences made of barbed wire or similar material that is directly attached to steel posts are adequately grounded and will not collect an electric charge. If you are planning to install a wire fence parallel to and near a power line, use at least one steel post every 150 to 200 feet to ground the fence.
Can electric fences build up an electrical charge?
Electric fences, being specially insulated from the ground, can pick up a charge from transmission lines. Usually, the charge will drain off when the charger unit is connected to the fence; however, when the charger is disconnected either for maintenance or when the fence is being built, a small shock may be produced. Contact your local electric cooperative for assistance. Typically such a shock can be prevented by:
- Shorting out one or more of the fence insulators to the ground with a wire when the charger is disconnected, or
- Installing an electric filter which will ground charges induced from a power line while still allowing the charger to be effective
Contact Great River Energy or your local electric cooperative for assistance if you have any questions; every situation is unique.