Reproduced with permission from Telecom NZ
Electric fences are one of the most common causes of interference when transmitting data. You can often hear the tick-tick of the fence on a voice call, and it may not be too annoying. But it is much more disruptive for data transmissions because computers are not as good as the human brain at shutting out interference.
- Electric fences need to be properly connected and the fence itself fully insulated.
- The electric fence energiser should be adequately earthed in moist soil. It should be earthed at least 10 meters away from phone cables or other electrical earths, including water pipes.
- All connections should be in good order - energised wires joined with reef knots are asking for problems. Always use joint clamps for permanent connections. Check them all at least once a year.
- Up to date insulators and energisers ensure your fences run efficiently as last as long as possible. (Polythene pipe insulators don't last very long, and porcelain or GRP are better). Energisers made after 1988 comply with the latest New Zealand standards.
- Use one wire of a fence as the ground return if soil is generally dry or stony.
- Keep wet grass and plants away from the fence as they cause leakage to earth, reducing the voltage on the fence while increasing the current and hence interference.
- Try to avoid running fences within 10 metres of telephone lines. Many telephone lines are contained in cables buried in the berm of the road, and may be directly under your roadside electric fence.
If you own and operate an electric fence and you or your neighbours have problems with data transmission, contact your electric fence manufacturer for further advice. Or visit www.telepermit.co.nz on the Internet.