Stored / Input Joules
This refers to the energy stored inside the energizer before the electrical pulse is delivered to the fence. This number may be higher than the energizer’s actual output joule rating.
Energizer Calculator
Power Your Fence with Confidence
Find the right energizer for your fence based on your livestock, fence size, number of electrified wires, and operating conditions.
Photo courtesy of Eubank Farms & F Squared Backgrounding
How Can We Help With Your Fence?
Choose a topic below to quickly find the information you need.
Energizer Calculator
Find a starting energizer size based on your fence, livestock, and operating conditions.
Enter the total physical length of the fence being energized.
Enter only the number of wires that will be connected to the energizer.
Light = little vegetation contacting the fence. Moderate = occasional grass or weeds contacting the fence. Heavy = frequent vegetation contact or difficult fence conditions.
Select Yes if you expect to add more fence to this energizer later.
Your starting estimate
Physical fence miles—
Total energized wire miles—
Suggested minimum energizer output—
Grounding Starting Point—
Target Fence Voltage—
Target fence voltage is a starting guideline. Actual fence performance can vary based on grounding, vegetation, fence construction, conductor type, soil conditions, and other factors.
Selected fence / vegetation load—
Selected power source preference—
USA Grazing Systems Rule of Thumb: When in doubt, allow approximately 1 output joule per mile of energized fence.
This calculator provides a starting estimate only. Energizer requirements can vary based on vegetation, fence construction, grounding, wire type, livestock pressure, soil conditions, and other factors. Manufacturer recommendations should also be considered.
Understanding Energizer Joules
Not all joule ratings mean the same thing. When choosing an electric fence energizer, it is important to know whether the manufacturer is listing stored/input joules or output joules.
Output Joules
This refers to the energy delivered from the energizer to the fence. When sizing and comparing energizers, USA Grazing Systems recommends comparing OUTPUT JOULES to OUTPUT JOULES.
Always check whether an energizer’s advertised joule rating is stored/input joules or output joules before comparing models.
Understanding Electric Fence Grounding
A properly sized energizer can only perform as well as its grounding system. Poor grounding can reduce fence performance and make it difficult to maintain the target voltage needed for effective livestock control.
Size Your Grounding to the Energizer
3 feet per OUTPUT JOULEUSA Grazing Systems Rule of Thumb: Allow approximately 3 feet of total grounding per OUTPUT JOULE. Example: A 3 output joule energizer would have a starting recommendation of approximately 9 feet of total grounding.
Space Ground Rods Apart
10 feet apartSpace ground rods approximately 10 feet apart from one another. Spacing ground rods apart helps each rod make effective contact with the surrounding soil.
Look for Moist Soil
Better Ground = Better PerformanceWhenever possible, install ground rods where soil conditions stay the moistest. Moist soil generally provides better conductivity than extremely dry soil.
Don't Mix Metals
Use Compatible Grounding MaterialsAvoid mixing dissimilar metals when connecting ground rods, grounding wire, clamps, and other grounding components. Use compatible grounding materials to help reduce corrosion and maintain reliable connections.
Keep Away from Other Grounding Systems
33+ feet awayInstall the electric fence grounding system at least 33 feet away from other electrical grounding systems, utility grounds, and metal water pipes. Always follow the energizer manufacturer’s instructions when a greater separation distance is specified.
Grounding requirements can vary based on energizer size, soil type, soil moisture, seasonal conditions, and manufacturer recommendations. The information above is intended as a starting guideline. Always consider the energizer manufacturer's grounding recommendations for the specific unit being installed.
Test My Fence — Find the Problem
A low-voltage fence does not always mean you need a bigger energizer. A problem with grounding, vegetation, connections, insulators, or a section of fence can pull voltage down. Use these steps to help narrow down where the problem may be.
BEFORE YOU START
Always turn the energizer OFF before disconnecting wires, making connections, installing or removing a temporary short, or making changes to the grounding system. Turn the energizer back ON only when a test specifically requires the fence to be energized. Use a digital electric fence voltmeter or appropriate electric fence testing equipment.
QUICK CHECKS
Check Voltage at the Energizer
Test the energizer and compare the reading with the voltage farther out on the fence. A large voltage drop can indicate a problem somewhere in the fence system.
Walk the Fence
Look for heavy vegetation touching hot wires, broken or cracked insulators, loose connections, poor splices, wires touching posts or grounded objects, damaged underground cable, and other places electricity may be leaking to ground.
Test Along the Fence
Take voltage readings at several locations. If voltage is good near the energizer but drops farther down the fence, the problem may be between the last good reading and the first low reading.
Isolate Fence Sections
If cutoff switches are installed, turn individual fence sections off to help isolate the problem. If fence performance improves when one section is disconnected, inspect that section carefully.
DIAGNOSTIC TESTS
Isolate the Energizer
Turn the energizer OFF before disconnecting any leads. Disconnect the fence from the energizer according to the energizer manufacturer's instructions and test the energizer with appropriate electric fence testing equipment. This can help determine whether the problem is with the energizer or somewhere in the fence system. Turn the energizer OFF again before reconnecting anything.
02 — Test the Grounding System
STEP 1 — ENERGIZER OFF
Turn the energizer OFF before installing the temporary short.
STEP 2 — CREATE THE TEST LOAD
At least approximately 330 feet away from the energizer grounding system, use suitable steel rods or another manufacturer-recommended method to intentionally load the hot fence by making good contact between the energized fence conductor and the soil.
STEP 3 — ENERGIZER ON
After the temporary short has been safely installed and everyone is clear of it, turn the energizer ON.
STEP 4 — CHECK THE FENCE
Use a digital fence voltmeter to verify that the temporary load has reduced fence voltage to approximately 2,000 volts or less.
STEP 5 — TEST THE GROUND SYSTEM
Using an appropriate digital electric fence voltmeter and following the tester manufacturer's instructions, check voltage on the grounding system. Excessive voltage on the grounding system can indicate that additional grounding, improved connections, or a better grounding location may be needed.
STEP 6 — ENERGIZER OFF
Turn the energizer OFF before removing the temporary short or making any changes to the grounding system.
Note: Ground-system test thresholds can vary by energizer manufacturer. Follow the specific energizer manufacturer's instructions when determining an acceptable ground-system voltage.
Use a Fault Finder
A digital fault finder/current meter can help locate a fault on a large fence system. Follow current readings along the fence and at junctions to help narrow the problem to a particular section.
Still Can't Find It?
If the energizer tests correctly, the grounding system tests correctly, and fence voltage is still low, isolate sections of fence and work outward from the energizer until the problem area is located.
STILL HAVING TROUBLE?
Every fence system is different. If you are having trouble finding the problem, give USA Grazing Systems a call. We will be happy to help you work through your fence setup.
417-275-5555Talk to UsProtect Your Energizer from Lightning
Lightning can reach an electric fence energizer from the fence side or through the electrical power supply. While no lightning protection system can guarantee 100% protection, a properly designed system can greatly reduce the risk of energizer damage.
Protect the Power Side
For plug-in energizers, use a quality surge protector at the electrical outlet. Electrical surges caused by lightning can enter the energizer through the utility power supply—not just through the fence.
PROTECT BOTH SIDES OF THE ENERGIZER
Give Lightning a Better Path to Ground
A lightning diverter or arrestor is installed between the fence and energizer to help redirect a lightning surge away from the energizer and into a dedicated lightning grounding system.
Installation varies by product. Always follow the lightning diverter or arrestor manufacturer's installation instructions.
DIVERT THE SURGE BEFORE IT REACHES THE ENERGIZER
Add Another Layer of Protection
An induction coil, sometimes called a lightning choke, can be installed in the insulated lead-out cable between the fence system and energizer. A common method uses approximately 50 feet of properly rated insulated electric-fence lead-out cable formed into approximately 10-inch-diameter loops.
WHY THE COIL?You may have heard that the coil “confuses” lightning. Lightning does not actually get confused. The coil creates electrical impedance that helps resist the rapidly changing lightning surge and works with the lightning protection system to help divert the surge toward ground.
Important: Use insulated lead-out cable specifically rated for electric fencing. Do not use ordinary household electrical wire.
THE COIL HELPS IMPEDE A FAST-MOVING SURGE
Keep the Grounding Systems Separate
The lightning diverter or arrestor needs its own dedicated grounding field. Do not connect the lightning protection grounding field to the energizer's normal fence grounding field.
65+ FEET APARTAllow at least 65 feet between the lightning protection grounding field and the energizer grounding field when possible. Follow the manufacturer's instructions if greater separation is required.
MORE GROUNDINGAs a starting practice, the lightning protection grounding field should have at least one more ground rod than the energizer grounding system.
GOOD SOIL MATTERSInstall grounding rods where they can make good contact with conductive soil and follow manufacturer recommendations for rod depth, spacing, materials, and connections.
HOW THE PROTECTION WORKS
FENCE-SIDE PROTECTION
Lightning Diverter / Arrestor
+
Dedicated Lightning Ground
+
Dedicated Lightning Ground
ADDITIONAL FENCE-SIDE PROTECTION
Lightning Choke / Induction Coil
CENTER OF THE SYSTEM
ENERGIZER
Electric Fence Energizer
Electric Fence Energizer
POWER-SIDE PROTECTION
Surge Protector
↓
Power Supply
Exact component order, placement, and wiring can vary by manufacturer and product. Always follow the installation instructions supplied with your energizer and lightning protection equipment.
NO SYSTEM IS LIGHTNING-PROOFNo lightning protection system can provide 100% protection, especially from a direct lightning strike. These measures are intended to reduce the risk of damage to the energizer.
NEED HELP PROTECTING YOUR ENERGIZER?
Every fence system is different. USA Grazing Systems can help you determine what lightning protection components may be appropriate for your electric fence system.
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