Electric Fence and Dry Soils

Those that rely on electric fence are all too familiar with its drop in voltage during the dry summer months. A once effective fence loses its shock value and animals become undeterred.

Why?

Firstly, let's cover how an electric fence works. The pulse leaves the "+" terminal of the fence energizer and enters the conductors. An animal touches the electrified conductor, creating a path, for the pulse, to the ground. The pulse travels through the ground/soil to the ground rod, where it enters the energizer via the negative terminal.

The key for this type of circuit is the soil. For the above system to work, the soil must be moist. The moisture reduces resistance against the pulse traveling to the ground rod.

When soils are dry, the resistance against the pulse is increased. This applies to rocky and sandy soils as well.

What's the workaround? There are two basic options:

• Increase the conductivity of the ground field
• Install as Positive/Negative Fence

Increasing conductivity

This is accomplished by either adding additional ground rods to the ground-field or moistening the area around the fence and ground rods.
Adding ground rods puts more metal into the soil, acting as an attractant to the pulse. The more attractive the ground-system is to the energizer's pulse, the better able it can direct the pulse back to the energizer. However, if the soils are too dry (resistant) the pulse will not be able to overcome the lack of moisture.
By moistening the ground field or fence line, you are eliminating some of the resistance in the fence circuit. Watering the fence line is practical for short runs, not large paddocks and perimeters. Watering the ground field only reduces resistance in one location.

Pos/Neg

If watering is impractical, a Positive/Negative fence is recommended. A Pos/Neg fence is installed so half of its strands are connected to the fence terminal. They alternate position with the second half, which are connected to the ground system. When an animal touches both a positive and negative strand, the most direct route for the pulse is out the "+" conductor, through the animal, into the "-" conductor which leads back to the negative terminal (via ground rod). This eliminates the need for moisture to aid the pulse in its travel through the soil. The drawback is an animal must touch both a "+ and "–" strand in order to receive a shock. Pos/Neg fences are very effective fences in dry areas.

A third (not widely available) option is the wide impedance energizer. Compared to low impedance units, they are capable of pushing a pulse through a wider range of fence resistances (low to medium) without loss in pulse power. A 6 joule low impedance energizer has an output of .59 joules at 5000 ohms of resistance, a 2.3 joule wide impedance unit has an output of 1.24 joules at 5000 ohms. Low impedance units are far more common and tend to cost less than wide impedance units. If you are in a dry, rocky or sandy area, a wide impedance is well worth the added expense.

Importance of energizer output in tall-grass

If the grass gets this tall, mow it! 

We all know that electric fence and grass contact don't go together all that well. The energizer sends the pulse through the fence, the grass leeches energy from the fence so that there is less energy when an animal touches the fence.

But overcoming grass contact is possible if a higher output (more joules) energizer is used. How does this work? By sending more energy through the fence than the grass can leech, you will have more available energy when animal contact is made to the fence.

If you're expecting significant grass contact (though not as much in the photo above) consider going with a higher output unit. Consult us (800-282-6631) if you have any questions.

A major fence energizer mis-truth

Those who have researched energizers have more than likely (almost certainly to be exact) encountered the Miles or Acres claims on energizers.

That's too bad, as this often causes folks to purchase an energizer that is too small for their fencing needs. How so? The number of miles or acres advertised roughly energizes a single strand conductor, above the ground (no grass contact) with moist soils for that distance—essentially lab conditions.

In comparison—an in use energizer's field conditions involve moist or dry soils, one or many conductors of varying conductivity and grass contact—much more resistance to and drainage of the energizer's pulse.

Points to consider regarding overall fence resistance and pulse strength:

• Poor conductors (high ohms = high resistance) inefficiently carry an energizer's pulse throughout the fence line. 
• Multiple conductors increase a fence's overall resistance. 
• Grass contact (weed-load) drains energy from a fence. 
• Dry soils lack the conductivity to adequately carry an energizer's pulse back to the negative terminal of the energizer. 

An accurate way to gauge an energizer's performance is its joules of output rating. A joule is the volume of electrical energy in a pulse. The higher the joules, the more energy available (after loss to weed and poor conductivity) to be sent down the fence—the larger the pulse, the higher its strength at the end of the fence.

But how many joules are needed for a specific fence?

The answer is it depends. A rule of thumb some go by is .25 joules per roll of net. Gordon (a Premier Consultant) goes by .5 joules per 3-5 nets (ElectroNet) if you maintain weed-load. That means if you keep the grass short enough (not totally eliminated) you should be able to get 3-5 rolls of 164' net energized (depending on soil conditions).

For more tips on choosing a fence energizer, read this blog-post. It goes over how to use our Energizer Comparison charts.

The miles rating is certainly an effective way to sell energizers but it doesn't say what the voltage will be at the end of that wire—there may be some, but possibly not enough to deter animals.

Fence connections (temporary)

There are right ways and wrong ways to bring power to a fence. The wrong ways often go unnoticed until the voltage drops and the livestock take a trek to the neighbor's garden. 

The cause (for this post) is insufficient metal-metal contact. If contact is poor, the pulse is still going to travel through the fence, but with a few added hiccups. Instead of directly traveling from the powerlink to the conductor, it has to 'jump' to make the connection. This jump is called arcing. 

The conductor above featured a poor connection so arcing occurred. This caused both the plastic and metal filaments to burn out. 

How to avoid poor connections—

If connecting at the end of a roll or net (or junction of two rolls), connect to the metal clip at the end of the net. This will provide the best metal connection (more metal to metal contact). 

If connecting at the middle of a net (or length of twine), wrap some MaxiShock around the superconductor (green/white strand on netting) or twine, then connect the clip. The MaxiShock will contact the conductors (in the twine) at more points than simply clipping to the net. 

If connecting to 4.5mm (or larger) conductors—wrap a RopeLink around the conductor (below). The rope link will touch the metal filaments at more points and provide a better connection. 

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.

Electric fence…what happens

What happens when grass touches energized fence wires?

Think of the wires as pressurized with excess electrons from the energizer's pulse. 

Green vegetation is a conductor—particularly when wet. When it contacts and energized wire, energy is pushed through the moisture in the stem into the soil. This is often called a "leak" (similar to a hole in a water hose) or a "short." 

In short—grass leaks electrons from the fence. However, if the energizer's pulse (joules output) is large enough, it can cope with the loss due to grass contact (overcoming weed-load). 

What happens when an animal touches the energized wires?

The high voltage of the pulse pushes electrons through the animal's point of contact (often nose or ears) then through the body's tissue and fluids and out through the feet/hooves/paws into the soil moisture. 

Is the animal's weight a factor?

The weight of a heavy animal compresses the soil. This reduces electrical resistance of the soil and increases the joules that can flow through the animal. 

This explains why heavy animals are more affected by electric fence and light animals less so. 

Weight (or the lack of it) explains in part why calves and lambs will seem to be less affected by a pulse than adult cows and ewes. 

Which species are most affected by an electric fence pulse?

In order from most to least: pigs, horses, cattle, canines (wet noses, bare pads) raccoons, sheep, goats, deer, geese, chickens and rabbits. 

This assumes a low-impedance energizer was used and adult animals are contacting the fence with their nose, beak or paw. 

Electric Fence Pulse

A pulse from an electric fence energizer lasts less than 3/10,000 of a second. The pulse's strength can reach up to 10,000 volts. That sounds extreme but static electricity is often as much as 25,000 volts.

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. 

How an electric fence works

Well, how does an electric fence work?

1. The fence energizer sends an electric pulse through its positive terminal to the fence. 
2. The fence then carries this pulse until an animal comes in contact with the fence. 
3. The pulse travels through the animal and into the soil/ground. 
4. The pulse is then absorbed from the soil back into the energizer via the ground rod system. 

So where do the terms joules, voltage and ohms come into play?

• Joules is the volume of electrical energy in a pulse (think gallons, pints etc. in water systems). 
• Voltage is the measure of pressure upon the pulse to move from A to B (similar to PSI in air and water systems).
• Ohms is the resistance to electrical flow (constrictions in these systems). Higher ohms reduce the felt pulse.   

Points to consider:
For a fence to be effective, we suggest a minimum of 3000 volts. This means the fence needs to have reasonable high pressure (voltage). But that's just half of it. The other half being the size of the pulse, which is measured in joules (read as released, not stored, on fence energizers).

High pressure (volts) behind a large pulse (joules) results in a deterring shock when the fence is touched by an animal. The smaller the joule (output) the smaller the potential shock and vice versa. Also, the lower the voltage the smaller the felt pulse.

If bigger is better (or so it seems), why do we recommend .5 joule units?
For fences with low resistance (ohms) and have high voltage (at least 3000v), a .5 joule energizer is enough to deter animals. Longer fences with more resistance need more joules in order for pulse to be felt. 

Picking a fence and energizer combination—did I get everything right?

If picking out an energizer or roll of netting for the first time strikes you as a daunting task don't worry—it does not need to be tedious.

When visiting Premier's website—below the logo and slogan are a series of tabs, Sheep-Goats-Poultry-Horses-Garden/Wildlife-Deer-Cattle-Hogs/Pigs-Camelids. (Before we go any further, camelids is a one word way of saying llamas and alpacas.)

Tabs shown above. 

Select the relevant tab for your fencing needs—I'll select sheep. Go to the left hand column and click on Fencing.


Your fence options should now be shown. Since we're discussing netting, we'll focus on the temporary and semi-permanent options. The main differences being, how often do you intend to move the netting? Daily/weekly—choose temporary. Less often? Semi-permanent.

Fencing options for sheep (Semi-Permanent options not shown). 

From there you decide on Plus or Standard nets (post frequency), length, height, strut or string verticals and type of spike. Don't forget support posts for ends, corners and any major directional changes.

Now that you've chosen your fence, it's time to choose an energizer. Unless you already have one, in that case you're done!

Click back over to Fencing and select Energizers (DC, AC or Solar).
At the top of the results select energizer comparison chart. This will take you to a chart detailing all of Premier's energizers.

Click on the type of unit you need, AC (plug-in) or DC (battery or solar).

In the upper right corner you can again select the type of species you are fencing. Scroll right and you will find the number of nets each energizer can power. There is a range, (i.e. 2-5, 3-6) depending on energizer output in dry grass/soil conditions. If your soils are typically moist, go with the higher number and vice versa in dry conditions.

Energizer power source are the selections at the upper left. Species type is at the upper right. (Energizers can be used for multiple species.)

These options should help narrow down energizer and net choices. As always, if you have any questions give us a call at 1-800-282-6631 and we'll help you out.




Coming soon—advanced filters to help narrow down your netting and energizer selections.

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.

Spring Fence Checklist

You're ready for spring. Your animals are ready for spring. Your pastures are ready for spring. But are your fences ready for spring? Before you set your flock or herd loose onto pastures that haven't seen use for a few months, make sure the fences are ready to keep livestock in and everything else out.

Walk the fence line(s). Check for branches or trees that may have toppled during a winter windstorm. If needed, clear branches and trees off of your fence and assess its condition. Most HT fences can bounce back after heavy branches have been removed. Other fences may need some more involved care. If the fence is in a flood prone area, remove any downed trees/limbs that could be washed into the fence.

Make sure all conductors are intact. If needed, mend with repair kits, ropelinks, twistlinks or gripples.

Check plug-in and battery energizers before use—the fence must be adequately electrified. For battery energizers, make sure the batteries are fully charged before bringing them to the field.

If using a PRS, this video details how to bring it out of winter storage and get it ready for spring fencing.

For more informational posts, click on the links below:

Before you buy or build a fence
Troubleshooting electric fences
Tips for setting up netting successfully
Netting: Struts or Strings
Netting: single spike or double spike posts?
Netting Tips

Plug-in Energizer Tips

A HotShock 5 Plug-in energizer kit. Everything that is needed to operate a fence 100' from an outlet. 

How do you energize a fence if it is 100'± from an electrical outlet? Here is the kicker—you are unable to use a battery or solar energizer setup. Only plug-in.

For some, their first instinct is to use an extension cord from the outlet to the energizer. We do not recommend this option. There are a few reasons—

1. Safety. If an animal chews on the cord, that is a direct connection to 110v AC (much different than a pulse from an energizer). 
2. Extension cords are unable to provide consistent power (vary depending on the cord). Also—connecting multiple extension cords increases the overall resistance of the electrical circuit. The energizer may not receive the amount of energy it needs. 
3. For some energizers (mostly AC/DC units) the plug-in adapter (called a brick) is usually not weather resistant.  

What's the best option for energizing your fence? Run an insulated lead-out wire from your energizer to your fence. MaxiShock Double Insulated Cable or DCPIW34 is recommended to carry the pulse from the energizer to the fence. The cable can be buried or set along your yard. 

If burying the cable in a high traffic area (i.e. beneath a driveway) run the cable through conduit. This will significantly reduce the amount of pressure the cable experiences. 

If not buried and you need to mow:

• Turn off your energizer and disconnect the cable. 
• Gather the cable as you would rope to take it out of the mower's path. 
• Mow. 
• Unwind cable and reconnect to energizer. 
• Turn on the energizer. 
• Test fence. 

If you have any questions on using energizers or fencing please contact us at 800-282-6631 or info@premier1supplies.com.

What you need to know about ground rods

Make sure ground wires are firmly connected to the ground rod. 

Ground rods may seem to be just a trivial item. After all, they're just a metal rod you pound into the ground. They seem more of an anchor for the energizer than anything else. Don't be deceived by their unassuming demeanor, ground rods are vital.

How so? Try using an electric fence without the recommended amount of ground rod (3 ft per joule of output). For example, if using a PRS 100, an energizer with 1 joule of output, pull the ground rod out of the ground by a foot or two. Check the voltage of your fence (with a fence tester). Pound the rod back into the ground. Check the voltage again. See a difference?

We've established that it's important. Next, let's look into how an electric fence works. 

1. The energizer fence terminal sends an electric pulse through the fence's conductor(s). 
2. An animal touches the conductor. 
3. The pulse travels from the fence through the animal and into the ground. 
4. The pulse moves through the soil (via moisture) and to the ground rod. 
5. The pulse goes up through the ground rod and back to the energizer (via the ground rod). Completing the circuit (and the animal receives a shock, learning to stay away from the fence). 

Note: all of above happens in 1/10,000 of a second. 

So what does the ground rod do? It picks up the pulse from the ground and brings it back to the energizer. 

However, if the energizer has a stronger pulse than the rod can pick up, an electrical charge can build up around the rod. Since the full power of the pulse cannot travel through the ground rod, an animal will not receive a full powered shock. The remedy? Pour water around the ground rod to increase the conductivity around the ground rod(s), or add additional rods. 

Why is this ground rod so far out of the ground? It's likely because we are using a 1 joule energizer and a 6' ft ground. At 3' of rod needed per joule output, the full 6' is unnecessary. 

It is possible to test to see if your ground rod is not adequate. Ground out the fence—with the fence off, place a metal rod on the ground and lean it against the fence's conductors. This will cause a 'dead-short' to the ground. Using a digital voltmeter, stick the ground probe into the ground and touch the fence probe to the rod. If a reading of more than 300v appears, you need more ground rod. Under 300v, you have adequate grounding.

Connecting an energizer to its grounding system.