An electric fence energizer is a vital component of any electric fencing system. It transforms low-voltage battery or electrical power into high-voltage pulses that run through the fence wires, delivering a non-lethal but memorable shock to any animal or person that touches the wire. However, like any electrical device exposed to the elements, electric fence energizers can succumb to wear and tear over time.
When an energizer starts to fail, your electric fence ceases to be an effective barrier. Livestock can wander freely onto roads or neighbors’ properties, wildlife can intrude on your land more easily, and you risk liability for any injuries or damages that result. Fortunately, with the right knowledge and a systematic approach, many common energizer problems can be efficiently diagnosed and repaired by the landowner.
This comprehensive DIY guide will walk you through the complete process of troubleshooting and fixing issues with your electric fence energizer. Follow these steps and you can quickly restore the power and security of your electrical fencing.
How an Electric Fence Energizer Works
To troubleshoot energizer problems, it helps to understand the basic components and operating principles:
- Power Source – Typically a 12V battery or a plug-in 110V/220V AC transformer. Supplies low-voltage power.
- Circuit Board – Takes the input power and converts it to rapid high-voltage pulses. Often incorporates a transformer, capacitor, switching transistors, and more.
- Output Terminals – Where the energized high-voltage pulses are distributed to the fence wires. Separate positive and ground terminals.
- Grounding System – Rods and wires that direct the pulses into the soil to complete the circuit rather than through the animal/person.
The circuitry pulses the output terminals over a thousand times per minute. When an animal contacts the fence, it completes the circuit between the positive and ground terminals, receiving a short pulsed shock.
Proper functioning relies on adequate power delivery, electrical conductivity and insulation, effective grounding, and dry components. Issues with any of these can cause faults.
1. Common Electric Fence Energizer Problems
Before starting diagnosis and repairs, familiarize yourself with the most frequent electric fence energizer failures:
No Power, No Pulses
- Dead or disconnected battery
- Faulty power connection
- Failed or blocked circuit board
- Faulty transformer
- Blown fuse
- Loose or corroded wiring
No Output, But Has Power
- Burnt circuit components
- Failed transformer
- Faulty transistors/capacitors
Low Pulse Voltage
- Weak battery
- Poor grounding
- Damaged or wet circuitry
- Excessive fence load/vegetation
Pulse Irregularities
- Broken wires
- Loose ground connection
- Intermittent electronic failure
Short Pulses
- Weak or small battery
- Inadequate grounding system
- External short circuit on fence
The following troubleshooting and repair steps will methodically check for and address these potential issues with your energizer.
2. Tools and Supplies Needed
Gather the following equipment before inspecting your electric fence energizer:
- Voltmeter
- Fence tester
- Wire cutters/strippers
- Electrical tape
- Wrenches and pliers
- Replacement fuses, wires, terminals, etc.
Also, have ready:
- Battery charger or alternate battery
- Extra grounding rod(s)
3. Initial Troubleshooting
Start simple before taking apart the energizer:
Check Power Supply
For battery-powered systems:
- Verify battery is connected properly, with tight terminals and clean contacts.
- Check battery voltage. Should be 12+ volts.
- Try charging battery or replacing with alternate battery.
For plug-in energizers:
- Confirm electrical outlet works and transformer box is plugged in securely.
- Verify all connections are tight on transformer. No loose, damaged, or corroded wires.
- Check fuse/circuit breaker on transformer. Replace fuse if blown.
Inspect External Wiring
Examine energizer output to fence for any severing, disconnects, deterioration, or shorts:
- Joints/splices intact and tight?
- Insulators and brackets securing fence wires?
- Wires contacting vegetation or ground?
Test Grounding System
Use voltmeter to check ground rod resistance:
- Disconnect ground wire from energizer terminal
- Attach one voltmeter probe to ground rod top
- Push second probe rod into soil around ground rod
- Check resistance reading – ideal is < 3 ohms per rod
If high resistance, pound rods deeper or add additional ground rods, spacing at least 10 ft/3 m apart in a “star layout” for best effect. Retest until resistance is acceptable.
Also, inspect ground wires for any damage or severing.
Read More: How To Clean Your Wooden Fences And Decking
4. Energizer Diagnostic Testing
If no obvious external issues are found, it’s time to diagnose the energizer:
Check Output Voltage
- Disconnect all fence wires from energizer output terminals
- Attach voltmeter leads to output posts of energizer
- Energize unit per manufacturer instructions
- The pulse voltage reading should reach 5,000+ volts
- Note if readings reach adequate voltage, but pulse duration is very brief (<0.15 sec). This points to short pulse issues.
Typical Causes:
- Weak/small battery
- Poor grounding
- External short
Use Fence Tester
An electric fence tester is a calibrated tool that indicates whether fence is energized to minimum effective pulse voltage and duration:
- Disconnect fence wires if necessary to directly access output terminals
- Attach fence tester across output terminal posts
- Activate energizer pulse
- Check reading on fence tester measuring dial
If energizer fails on any of above tests, further internal diagnosis is required.
Check Integrity of Internal Components
With power source removed, open up energizer case following manufacturer directions to visually inspect:
Check:
- Any damage, corrosion, burned marks or melted wires/parts?
- Obvious breakage of solder joints, transistors or capacitor body cracks?
- Loose, disconnected wires or degraded insulation?
- Moisture intrusion, dirt/debris contamination?
- Corroded battery contacts or faulty power connection points?
Typical Causes:
- Environmental moisture/contamination
- Overheating failure
- Loose wiring arcing
Conduct Resistance Testing
Use a multimeter in resistance testing mode to methodically check conductive integrity of internal components down to the resistance (ohms Ω) level:
Checkpoints:
- Battery wires & contacts
- Fuse
- Transformer wiring
- Capacitors
- Switching transistors/silicon diodes
- PC boards
Compare resistance values to factory service specifications when available. Out-of-range readings indicate faulty components.
5. Repairing the Energizer
Upon identifying the issue through testing, here are some tips to restore normal energizer function:
No Power:
- Recharge or replace battery
- Restore power connection
- Replace fuse
- Clean/tighten wiring connections
Burnt/Failed Components:
- Replace damaged wires/insulation
- Solder/replace broken connections
- Swap out defective capacitors, switches, boards, lightning arrestors, etc. Match new parts to original electrical load capacities and specifications.
Moisture Contamination:
- Dry out energizer case interior and components with fan
- Prevent future moisture intrusion by resealing box, wire conduits, etc.
Poor Grounding:
- Drive additional ground rods
- Verify all ground connections intact in energizer
External Short:
- Inspect fence wire alignment, insulation, vegetation contact, etc.
- Clear shorts, replace insulators/supports as needed
Fix Loose Wiring:
- Resolder loose wire connections
- Replace damaged wire insulation
- Securely fasten all interior wires
6. Preventative Maintenance
With repairs complete, follow these electric fence energizer maintenance practices to prevent frequent failures down the road:
Routine Inspections
- Monthly quick checks: stable mount, clean vents, intact box, wires in good condition, adequate fence vegetation clearance
- Annual deep inspection: disassemble, inspect interior components for damage/wear, test all functions
Keep Components Clean and Dry
- Clear energizer vent openings
- Keep box sealing tight
- Store indoors when possible
- Prevent moisture from traveling down wires
Avoid Electrical Overloads
- Size energizer per fence length/condition
- Use lower-impedance fencing
- Minimize non-animal loads like weeds/debris
Emergency Repairs
- Keep spare energizer on hand
- Stock replacement parts like fuses, lightning arrestors, transistors
- Backup battery
Proactive Grounding Upgrades
- Optimal: At least 3 x 8 ft long copper/galvanized steel ground rods, spaced 10 ft+ apart in soil
- Verify ground connections solid on energizer
- Consider additional ground wire to water lines/other systems
Battery Maintenance
- Store battery warm/dry during winter
- Clean terminals
- Keep charged when not in use
- Replace every 2-3 years
7. When to Call a Professional
While many issues can be addressed with the user troubleshooting and repairs here, certain energizer problems should be handled by a professional:
- Diagnosing cryptic intermittent issues
- Repairing lightning or catastrophic electrical damage
- Complex custom rewiring jobs
- Major circuit board repair
Unless you have specialized technical skills and equipment, energizer problems beyond basic diagnosis/fixes often require a professional. The cost of professional repairs is also typically less than the price of an entirely new energizer.
An experienced electric fence installer has the background to efficiently troubleshoot and resolve even difficult failures. They also have access to manufacturer parts and technical specifications for your model.
Conclusion
Electric fence energizers are exposed to the stresses of weather, wildlife, and electrical overloads. Thus, problems inevitably arise over time that sap power and reliability if left unaddressed. Knowing the common issues and methodically diagnosing the source of failure are the essential first steps to repair.
In many cases, such as dead batteries or faulty connections, the fixes can be as simple as replacing a single part. Even more complex component failures can be within reach of DIY repairs using basic wiring/soldering skills guided by this energizer troubleshooting manual.