Installing Electric Bear Fence for Protecting Beehive

The task turned out to be more complicated than I originally planned. Mainly because I couldn’t find all the parts at one store, but also because of the fact that I was in learning mode along the way. In the ensuing paragraphs I share with you what I learned about installing electric fences for bees and how and what I actually installed for an electric bear fence.

Electric Fence Sizing

In regards to the size of my electric bear fence, I made it roughly twelve feet by twelve feet, with the beehive box centered in the middle of it. This size ensured that the beehive would be at least five feet away from all sides of the electric fence, well outside the distance of a bear’s reach. I used four 5-1/2 foot long metal T-posts to set the perimeter of the fence and attached insulators that easily clipped onto the T-posts.

Electric Fence Chargers

I then researched electric fence chargers. There are basically three types to choose from: AC powered, DC (battery) powered, and solar powered. Due to the fact that my beehive is not located near AC power, and the fact that I didn’t want to spend an excessive amount of money on a solar powered electric fence charger, I decided on a DC electric fence charger. The charger is powered by a 12 volt deep cycle marine battery. From what I have been told the battery should last a good month on a single charge, assuming the electric bear fence isn’t shorting out to ground via grass, weeds and branches touching it.

Also in regards to electric fence chargers, I learned for bears that the electric fence charger should be able to output at least 0.7 Joules of energy. I chose one that outputted 1 joule. From what I learned, anything less than 0.7 joules of energy would provide such a minimal electrical shock to the bear that it would likely not be enough to frighten off the bear.

In regards to the battery I chose a 12 volt deep cycle marine battery that provides 40AH. The charger simply connects to the two leads on the battery.

Grounding Rods

Another key component associated with installing an electric bear fence are grounding rods. I pounded two 3 foot long grounding rods into the ground, within a few feet of the charger, and tied them together with 20KV insulated wire using ground rod clamps. I then attached one end of the grounding rods to the ground side of the electric fence charger.

I also installed four electric fence handles, one for each perimeter wire loop. One end of each handle attaches directly to one side of the wire loop, and the other end attaches to a small ½ inch loop on the opposite end of the wire to close the circuit.

After installing the four electric fence wire loops I tied them all together with one vertical running piece of 14 gauge wire. I then immediately followed by attaching one end of a length of insulated 20KV rated wire to the electric fence wire and the other end to the high side of a large cut-out switch.
Lastly, I attached another length of insulated 20KV rated wire to the low side of the large cut-out switched, and the other end to the positive terminal on the electric fence charger.

Note that I mounted the cut-out switch on a wooden pressure treated post that was pounded into the ground just outside the fence. Also, I mounted the electric fence charger on a similar post, but that post was located within the confines of the electric fence. Lastly, I placed the battery in a water-tight container that sits on the ground, next to the electric fence charger.

After finally completing the electric bear fence installation I tested out the fence with a specifically designed electric fence tester.

After energizing the charger I was able to confirm via the tester that the charger was outputting a 7KV+ pulse onto the electric fence. It is important to note that electric fence chargers output a pulsed voltage at a 1 second duty cycle rate. This way an animal doesn’t get “stuck” on the electric fence. Once the pulse is shot out by the charger, the charger briefly turns off and any animal that is touching the electric fence wire can pull away from it.

So when my bees arrive in the next few days, thanks to my newly installed electric bear fence, I’ll be able to sufficiently protect them from curious bears.