Marks request was

>I am setting up my electric bear fence. =20

>What voltage do I need to keep bears out?  Bear populations are at =
>record levels  here in Minnesota, so a fence is a necessity.

>Any advice?

I read with interest the problems you have with bears and while my hives
will never see a bear, I do have some home grown guys down the road from me
that have made it big in the electric fence business. One of their people
modestly supplied the following and you can find more about the Gallagher
Group and their shocking ways on www.gallagher.co.nz

Regards
Bryan Clements



There are a variety of fence designs regarding bears. Experience in Canada
has shown that bears confronted with a five wire HT wire fence of five
wires  are repelled very well indeed. The five wires are an earth return
system. The first wire from the bottom is live and the next earth etc.
Billy
or Beatrice the bear now create their own circuit between the wires and any
climbing activity results in a most memorable shock. The bottom wire being
alive prevents the crawling bears.

The wire spacings are , starting at the bottom, 150mm, 150mm, 150mm,
200mm,250mm. Insulation is important and there are products such as
"Insultimber" available to help the beekeeper erect a fence in quick time.

There are a variety of Power Fence units available and always try to
purchase the one that delivers the most energy to the fence. Ask your
supply store to explain the difference.  If the location is remote there is
a selection of Solar style units that will keep a battery charged. Voltage
will be around the 2500 plus on the fence. More important than voltage is
the energy rating of the energizer. Look for the JOULE rating, that is the
grunt part of the energizer. It is possible to have a reasonable voltage
and not a lot of "kick" on the wire.
Always sign the fence with safety signs to prevent accidental touching,
bears cannot read so that is not a hassle. Always check the energizer you
purchase has the safety standards that apply to your country.