How to Test an Electric Fence Without Touching It
Congratulations! You’ve installed your electric fence. It’s always smart to test your fence immediately after installation. But that’s not the only time you should check it. You should do routine testing daily to make sure you’ve charged the lines. Thoroughly and regularly test the fence as described below. You don’t have to test the fence by touching it, of course! You’ll use a tool known as a voltmeter to check that your fence is functioning as expected.
The voltage on the lines will generally be somewhat lower than the output of your charger. That’s because the wires themselves cause resistance. The resistance isn’t a problem as long as the active voltage is in the desired range. Typically, this range is over 2,000 volts for horses or over 4,000 volts for other types of livestock. Some fences have an even higher voltage to prevent pests and predators from entering the enclosure.
Also, the active voltage may be somewhat higher on the fence than the voltmeter registers, due to the resistance caused by the earth. You’ll notice that the voltage is higher near the charger and lower the farther you are from it, as a result of this.
Visually Inspect the Fence
Before you begin your test, visually inspect the enclosure. If obstructions are touching the fence, like weeds or other foliage, broken components (insulators, connectors, wires), or sagging wires, attend to these before the test.
Check the Power Source
If you’ve powered the charger via an AC outlet, make sure that the outlet is functioning correctly. If your charger is battery or solar powered, check to make sure that you’ve fully charged the battery.
Test the Charger Output
Disconnect the positive lead to the fence. Once you’ve disconnected the jumper cable from the charger, you can use your voltmeter to test the charger’s output from the positive to the negative terminal. Double check that the reading you get is in line with what your charger’s output should be. Checking the manufacturer’s manual, which should give you a range of expected voltage output for comparison.
Check the Grounding Rod Connections
Once you’ve determined that the charger’s power supply is functioning and its output is acceptable, it’s time to test the grounding rods. If you have more than two grounding rods, you can disconnect the final rod and check the voltage between the end of the wire and the disconnected grounding rod. A high voltage here indicates that power is “leaking” into the earth via the grounding wire.
Test the Fence Wires Close to the Charger
You’ll want to test the wires at several points, but you should begin near the charger to ensure that the charge is sufficient there. If this is the first time you’re testing the fence, refer to the manufacturer’s manual to check that the voltage is within the expected ranges. If this is a routine test after having the fence installed for some time, you’ll also want to compare the voltage with previous measurements. Keep a fence maintenance logbook. Drastic changes could indicate an issue with your fence’s functionality.
Test the Wires Along the Entire Enclosure
If the voltage is sufficient near the charger, you’ll still need to test along the fence. We recommend checking each wire at least every other fence post. You may note that your readings gradually drop as you move away from the charger. You should expect the drop, so long as the total drop (farthest from the charger) is no more than 2,000 volts.
What If There’s a Problem?
If you notice that the voltage is low near the charger, you may be dealing with a short in the fence caused by interference or faulty hardware. If the first readings are sufficient, but the voltage declines rapidly or too much as you move further away from the charger, it could be a grounding issue.
To determine what the problem might be, check out our article on Electric Fence Problems and Troubleshooting. In these articles, we identify some of the most common problems with electric fences, how to identify them, and what you can do to fix them quickly, effectively, and at an affordable price.