You are here:     Electric fence school › About AC-powered fence chargers

Electric fence school

• Alternative uses
• Shock principles
• Fence planning
• Fence layout
• Wire configurations
• Wire types
• Post types
• Insulator types
• Uninsulated fences
• Electric fence accessories
• Grounding tips
• Shock requirements
• Low vs. hi-impedance
• About AC chargers
• About DC/solar chargers
• Radio freq. interference
• Electric fence safety
• Storage and cold weather
• Troubleshooting tips

---

Hallman.ca is best viewed in Mozilla Firefox at a screen resolution of 1024 x 768 or larger.

PDFs require a PDF viewer. Hallman recommends Foxit PDF Reader.

Electric fence school

About AC-powered fence chargers

Here are some things to consider when choosing an AC-powered fence charger.

 Output versus cost

AC-powered fence chargers are less expensive than battery powered fence chargers. Being powered by electricity instead of a battery, simplifies the circuitry needed to produce a large shock.

Another surprising fact is that few AC-powered fence chargers use even one dollar's worth of electricity a month.

 Indoor mounting

Most AC-powered fence chargers can be mounted only indoors. The cost to run weatherproof wiring and outlet facilities to a remote location, and the costs to manufacture a fence charger that will pass CSA's or UL's outdoor tests, make outdoor-mountable AC-powered fence chargers too expensive.

 Shock comparison

Is best to select a low-impedance fence charger in nearly all instances; they are usually marked on the label. All Hallman fence chargers are low-impedence models.

Low-to-medium priced fence chargers will power up to 16 km (10 miles) of single-wire fence. Some of the higher-priced, higher-powered units will power up to 80 km (50 miles) of fence.

An 80 km fence may seem ridiculous, but if a predator control fence consists of five live strands, then the fence could only be one-fifth as long, or just 16 km. If there is very considerable green growth against the lower two strands, then even more shock would be lost, possibly reducing the controller's ability to power more than about 14 km.

 Lightning protection

The probability of lightning damage is hundreds of times greater in AC-powered fence chargers than battery-powered ones. Good manufacturers will add various components to their circuits to help reduce serious damage and will usually advertise this fact. Don't be afraid to ask your dealer. The electrical energy that will split a huge tree will certainly not respect a tiny fence charger box.

 Indicator lights

Most AC-powered fence chargers have at least one light that indicates that the internal electronic circuit is capable of producing a shock. Sometimes this light actually samples the shock at the output terminal, giving an indication of the shock level.

Some fence chargers have two lights; one of each of the two types described above. Although lights may seem to be a frill, they serve a purpose in helping a repair technician, thus saving time and money.

 Fuses

CSA-approved AC-powered fence chargers must have fuses. Some models have two identical fuses. If the line cord has a ground prong (a third prong), then there is very little advantage to this. Fuses provide very little protection against lightning damage.

 Size

Although it takes little space for an electronic circuit that produces an adequate shock, most reputable manufacturers realize that eventually a fence charger will need repairing. These manufacturers make the fence charger enclosures large enough to allow comfortable and rapid repair. Fence chargers that have small enclosures, but produce high output, can be costly to repair!

 Output taps

Some high power fence chargers have more than one level of output. This is usually accomplished by separate output terminals for each, although in some cases a switch is used. Most controllers that have multiple output terminals can only use one terminal at a time, otherwise the shock collapses.

Goat or sheep farmers often need to operate two separate fences simultaneously, at different shock levels, and without the expense of having a second fence charger. If you need this multiple tap feature, be sure to ask your dealer about it—some fence chargers do have it.

 Cold weather

Some AC-powered fence chargers operate better than others do at low temperatures (less than -18°C or 0°F). Some will pulse normally, but have low shock output. Others will not pulse after they have been turned off and allowed to cool down.

For more information, read the section Storage and cold weather use.