The Gallagher M550 provides a useful step up from a standard paddock energiser. It is designed for permanent electric fences that need a dependable supply of power throughout the year, including longer horse paddocks, cattle and sheep boundaries and systems serving several grazing areas.

Its maximum 3.9 joule output gives the fence a good reserve for light vegetation, multiple live wires and the small losses that naturally occur across a larger installation. Gallagher rates it for 9km under recommended working conditions, 25km with light vegetation and up to 35km in ideal conditions.

Those distances refer to the total length of electrified conductor rather than simply the distance from one end of a field to the other. For example, a 2km perimeter fitted with three live wires has approximately 6km of conductor before allowing for divisions, gateways and connecting runs.

Active power adjustment helps the energiser respond to changing conditions on the fence. A clear LED shows that the unit is operating, and integrated lightning protection provides additional protection against surges entering from the fence line.

This model needs a correctly installed earth system to complete the electrical circuit. Gallagher recommends three 1.7m earth stakes, preferably positioned in ground that remains reasonably moist. Dry, stony or sandy soil may require additional attention to achieve satisfactory earthing.

The M550 should be mounted indoors or in a suitable dry, weather-protected location close to a 230v mains supply. Insulated high-voltage lead-out cable should be used to connect it to both the fence and the earth system.

Earth stakes, insulated lead-out cable and other installation materials are purchased separately.