When an electric fence isn’t working properly, the most common culprit is reduced voltage. Whether it's caused by vegetation, poor grounding, or damaged components, voltage loss can compromise the entire system and leave animals uncontained. That’s why fault finding is one of the most important maintenance tasks for any electric fence setup.
Fortunately, with the right tools and a simple process, you can quickly isolate and fix issues before they become major problems. This guide will walk you through the most common faults, how to check each one, and what steps to take to restore full power to your fence.
There are a number of reasons for reduced voltage on the fence line:
- Vegetation growth
- Broken wires
- Corrosion
- Poor grounding
- Bad connections
- Poor insulation
- Increasing the length of fence
Recommended Tools:
- Voltmeter with fault finder - The most important piece of equipment required to check for faults is the Voltmeter. With a voltmeter you can pinpoint faults accurately.
- Wire strainers
- Pliers
- Adjustable wrench
- Quick splices, split bolts, crimps, Gripples, and/or other connectors
Faults To Look For:
- Is the energizer switched on?
- Always check the voltage at the energizer first.
- Is the lead out wire connected to the energizer and the fence line?
- Is there a break in the lead out?
- Is the ground wire connected to the energizer and earth rods?
- Is there a break in the ground wire?
- Are all the cutout switches turned on?
- Is there a dead short on the fence line?
- Are there any faulty or broken insulators?
- Use the fault finding chart below to help you locate faults.
To check if the energizer is faulty, disconnect both the lead out and the ground wires and test the energizer without any load. If the energizer is reading below the manufacturer's specification (usually 7.0kV) there could be a fault with the energizer.
If the energizer is reading normal (7.0kV and higher) then:
- Check the ground system before checking the fence line.
- If no fault is discovered with either the energizer or the ground system, then check the fence line.
- The use of cut out switches makes the job of finding faults easier as different sections of the fence can be isolated. When the area of fence which is at fault is switched off, the voltage on the remainder of the fence will rise.
- Once you have isolated the section of fence at fault, move along the fence line and take voltage readings every 330ft.
- The readings will continue to drop until you reach, or pass the fault. After the Fault, the readings should remain constant. (Remember there may be more than one fault).
Induction:
A phenomenon known as induction is common with electric fences. This is the transfer of electricity from an electrified wire to a non electrified wire without the wires physically touching each other. This is often mistakenly blamed on insulator leakage. This phenomenon is also more common in areas where the air is damp such as in conditions of fog. As this phenomenon is a quirk of nature it cannot be stopped from occurring.
However, to avoid receiving shocks caused by induction on non electrified fences and gates etc. you can "ground out" the offending fence by connecting a ground wire to all wires on the non electrified fence. Push the end of this wire into the ground as far as possible and this will send all the offending voltage into the ground.
Note: Induction has very little effect on the voltage on the electrified fence.
Radio Interference:
All cyclic wave energizers comply with the usual regulations, but problems can occur for various reasons, particularly in areas with poor radio reception. These are usually noticed when an audible "click" is heard on the radio and coincides with the pulsing of the energizer.
To reduce or eliminate the problem, look for faults in the following areas:
- The energizer ground must be very good and should be at least 33ft away from any other ground. No part of the energizer ground system should come into contact with any buildings.
- Avoid having any lead out wires or fence lines running parallel to telephone or power wires.
- Check for any fence faults such as broken insulators, poor connections and joints, any shorting caused by broken wires etc. Also check that cut out switches are not arcing.
- Check that no underground cable has been damaged and is shorting out.
- Walking the fence lines with a portable radio tuned off the station and on high volume is a quick and easy way to locate any electrical leakage.
Keep Records of Your Fence
Keeping accurate records is a key point for any large or intricate fence system. You should keep a note pad and record the common voltage you read along your fence. Our example below includes:
- A basic layout of the fence
- Gates Cut-out switches
- The direction of the voltage
- Underground wire
- Where the energizer connects to the fence
We also started a record of when the fence was installed and the voltages read at that time. A few months later, the fence was tested and the voltage was recorded. It is critical to test your fence periodically and note the time of day and any weather conditions or soil conditions, such as 2 weeks of rain, heavy vegetation, tested in the morning while the fence line was wet with dew.
By keeping records, you can quickly diagnose issues along your fence line. Not only will you be able to identify if the voltage drop is due to ground conditions or a fault, you will have an average reading of your fence for reference. By knowing your typical fence conditions, you can determine if you need to investigate further for problems such as a downed limb or cracked insulator, or to know that you need to add moisture to your ground bed.
Brace Wires and Other Hidden Shorts
If you do not have cut-out switches installed, start by testing on either side of any gates or underground connections. If your loss of voltage is on the opposite side of the underground wire or gate, you will need to replace the underground wire. If all your gates are OK, check your corners and brace posts for any hot wires touching non-insulated wires, such as brace wires.
If you do identify this as your loss of voltage, unplug your fence and insulate the touching wires using a coil of Spiralator insulator tubing. If you are still unable to identify your fault, continue checking down your fence line for any poor connections such as crimps or where wire is knotted, and check for any cracked or missing insulators.
Materials to Keep on Hand
Kencove offers a large selection of the tools and supplies you need to make quick, simple repairs or to overhaul your entire fence. Some common materials to have on hand for quick repairs are:
- Crimps
- Extra wire
- Extra insulators
- Spiralator insulators
- Wire cutters
- Crimping tool
- Gripple Tensioners
- Gripple Torque Tool
- Strainers
- Underground wire
Here's a quick checklist to summarize the fault finding process:
- What is the voltage reading on the fence line? Is the voltage lower than normal?
- Check the voltage reading at the energizer while grounded but under no fence load. Under 7.0kV indicates an energizer issue. 7.0kV and higher indicates an issue on the fence line
- Check lead out wires for connection quality and damage
- Check that the ground voltage is not greater than 300 volts
- Walk the fence line with a fault finder looking for issues.
Common fence line faults are:
- Lead out wires
- Damaged underground wire
- Poor joints, connections, and splices
- Damaged insulators
- Vegetation growth
- Accidental shorting or arching
Final Words
Troubleshooting your electric fence doesn’t have to be complicated. With a voltmeter, some basic tools, and a systematic approach, you can identify and resolve most issues on your own. Regular checks and proper maintenance will keep your system running efficiently and your livestock safely contained.
For dependable fault-finding tools and replacement parts, check out our Electric Fence Supplies.
