Electric fence basics: Conductivity

An energizer sends a pulse (measured in joules) through the fence. When an animal touches the fence the pulse travels through them, to the soil and to the ground rod. The pulse travels from the ground rod to the energizer completing the circuit.

Conductivity is the measure of how easily an energizer's pulse flows through the electric fence. Better conductivity results in a more consistent pulse (no loss of strength) from the energizer to the end of the fence. 

The lower the conductivity, the higher the ohms. More ohms = higher resistance to the flow of the energizer's pulse.

Low conductivity means more resistance to the pulse (measured in ohms).

• Low ohms = low resistance
• High ohms = high resistance

How does this information apply to an electric fence?

The pulse is made up of a group of electrons that travels through the fence circuit. Over distance (throughout the circuit), the pulse loses electrons—similar to erosion—from the resistance. More resistance = more electron loss. The fewer available electrons at the point of contact/end of fence, the weaker the felt pulse.

The better the conductivity, the fewer electrons lost, better possibility for a deterring shock.

Dry/rocky/sandy soils tend to lack moisture, which results in poor conductivity. The best way to try and overcome this is to use wide-impedance energizers, increase the total feet energizer grounding (ground rods) or use pos/neg fence.

Build fences with low ohm conductors. This includes the majority of our white or green netting, black and white conductors and MaxiShock. This will aid in lowering the overall resistance of the fence.

What exactly is a fence energizer?

It is simply a box that takes in small amounts of electrical energy from an outside source (battery or 110v outlet).

The energizer pushes this energy from the outbound (positive, fence) terminal in very brief, high voltage and high amperage pulses, The ground terminal's (negative, earth) purpose is to absorb as much of the pulse energy as possible back into the energizer. 

An electric fence is the extension of these two terminals (fence and ground/earth).  

The inbound terminal is extended by driving metal rods (ground rods) into the soil and connecting them to the earth terminal with conductive wires to it. 

The outbound terminal is extended by attaching conductive wires to it. They are suspended above the soil and kept separate from the soil by insulators and/or nonconductive posts. 

Fall Grazing Tips

This sight will be common within days. 

Think of each blade of grass as a solar panel. The panel charges the plant's growth. In fall, with less light available for growth, grass needs more ​surface​ ​area​, than summer months, for the same regrowth—if the amount of moisture remains a constant. Gordon S. (Premier consultant and raises 200+ ewes on grass) prefers to move when grass length is 4" (a good practice to use in general). 

This leaves the plant enough solar collection ability to regrow without drawing from its roots (drawing via the roots reduces available energy for spring growth). 

Also consider fencing off shaded areas. While essential during summer months, they attract heavy traffic which leads to bare, barren dirt (not good). 

Solutions:

• Increase rotation speed (i.e. less time in one area). Less time grazing (one location) = more grass available for collecting sunlight. 
• If an area is already overgrazed, fence it off. Same practice for shaded areas—if it's cool, fence off the trees.

For fencing out of the way areas, consider using a solar fence energizer. 

In either case, we use netting to accomplish this. It is quick to install and easy to move. Fall rains bring soft soils so nets with double-spikes are preferred by many (though we find single-spike just as effective on our farm). Though if we graze later into the season, nets with drivable posts (DP) would be advised (hard/frozen soils). 

Introducing PRS-I and PRS-B energizers

This Spring Premier added several new units to its PRS Energizer line-up. These units offer some of the same features of the original PRS line-up but with added enhancements.

Details…

• Output 0.5 or 0.25 joule. 
• Same UV treated, high-impact plastic outer case but the energizer inside varies in joules of output and energy use/hr.
• Include a backup battery charger.
• Have an easy-access on/off button.
• On/off button shows up very well at night (flashes green or red depending on battery charge level).
• Have an overcharge regulator to protect the battery.
• Can be placed on the ground or on the top of steel T posts.
• Include wires and clips to connect to the fence and the ground rod. 
• Larger batteries (in amp-hr) than competing units of similar output.

PRS-I vs PRS-B?

A “PRS-B” (for “Basic“) unit removes a steady 50 milliamperes per hour from the battery—which in turn must be recharged by the solar panel.

“PRS-I” units (for “Intelligent”) are able to reduce their energy demand when the fence’s voltage is high—due to few weeds touching the fence. 

This occurs in fall and winter for most fences and occurs all year for some horse, cattle and deer fences.

So an “I” unit’s battery is more likely to remain charged through the low sunlight days of autumn and winter.

0.25 vs 0.5 Joule?

0.25 joules will work for a roll of sheep netting or a strand of “weed-free” rope. It’s also enough for most cattle and horse temporary fences. Will work with a roll of PoultryNet or VersaNet but grass must be mowed or sprayed as needed to maintain adequate voltage. 

For multiple rolls of net we advise 0.5 joule units or larger.

Below is a video of setting up a new PRS for in-field use. If you have any questions give us a call at 1-800-282-6631 or visit our website at www.premier1supplies.com.