Electric Livestock Fencing: Installation and Safety Standards

1. Purpose and Scope

The purpose of this instruction is to determine the specific requirements for electric fences used for livestock, including their power supply and installation. An electric livestock fence is defined as a barrier for animals comprising one or more conductors, such as wires, bars, or barbed wire. The fence energizer is the apparatus that supplies regular voltage pulses to the connected fence.

2. Power Supply

The electric fence energizer can be powered by one of the following methods:

• Connection to an electricity distribution network.
• Connection to batteries or accumulators charged via an electricity distribution network.
• Connection to autonomous batteries or accumulators not intended for connection to a distribution network.

3. Special Requirements

Energizers connected to a power distribution network must comply with the UNE-EN 60335-2-76 standard and the power circuit requirements of ITC-BT-22, ITC-BT-23, and ITC-BT-24.

Installation and Safety

• Placement: Energizers must be placed in areas free from flammable materials like straw or hay and located near the fence they power.
• Clearance: Conductors must be separated from unrelated metal objects to prevent accidental contact.
• Support Restrictions: Fence conductors and their connections must not be supported by pipes used for high or low voltage, telecommunications, or other utilities.
• Gate Operation: Gate maneuvering elements must be conveniently isolated. Operation should effectively de-energize the conductors between the lateral gate supports.
• Fence Separation: To prevent simultaneous contact by people or animals, fences powered by different energizers should maintain a minimum distance of 2 meters.

Warning Signs

Warning signs must be installed where fences are accessible to the public or near public roads:

• Frequency: At least one sign per fence alignment, with a maximum spacing of 50 meters.
• Visibility: Signs should be placed in conspicuous locations, preferably on the top conductor or the support structure, visible from both inside and outside the enclosure.
• Design: Signs must feature the text "ELECTRIC FENCE" on an equilateral triangle with a horizontal base, using black letters on a yellow background.
• Dimensions: Minimum size of 105 x 210 mm with a minimum letter height of 25 mm.

Grounding and Lightning Protection

The fence grounding system must be independent of any other grounding system, including the grounding of the energizer's own chassis. In areas highly exposed to lightning, the energizer should be located outside of buildings or within a specifically designed enclosure with appropriate protective measures.