We have a couple of hives in our deer netted enclosed garden. Not much protection against a possible bear, which occasionally one is seen. The entire perimeter where I would hang the electric fence is about 200’. Wondering what size output energizer I would need given the short run needed (and if a factor)? One joule? Three joules? I’d prefer an AC unit and our ground is usually wet.
"In terms firstly of base SI units and then in terms of other SI units, a joule is defined below, where kg is the kilogram, m is the metre, s is the second, N is the newton, Pa is the pascal, W is the watt, C is the coulomb, and V is the volt:
J = kg ⋅ m 2 s 2 = N ⋅ m = Pa ⋅ m 3 = W ⋅ s = C ⋅ V
One joule can also be defined as the following:
The work required to move an electric charge of one coulomb through an electrical potential difference of one volt, or one coulomb-volt (C⋅V). This relationship can be used to define the volt.
The work required to produce one watt of power for one second, or one watt-second (W⋅s) (compare kilowatt-hour – 3.6 megajoules). This relationship can be used to define the watt."
Look at the Joule. It has a time component. If you increase the time, you increase the Joules. So if your electric fencer is on for 40 microseconds instead of 20 microseconds, you just doubled your Joules. This does not make it a better fencer. I prefer the rating system of volts at 500 ohm load.
I`m not familiar with their AC units but the Parmak Solar 6 is a very good fencer.
I agree. If you are looking for solar or battery operated, the Parmak is likely the best.
I have used the Super Energizer Parmak for years. The current model is the SE5. I have not bought one in many years as they are quite reliable. You will need a surge protector to plug it in. Most failures are from surges from the power side, not from the fence side.
Although I do not have bears, it appears that bears need a stronger shock than most predators. If you purchase a cheap fence charger, it may not be strong enough to deter a bear. I have no bear experience. Parmak rates the SE5 for bears, but its a considerable expense. Since I started using surge protectors, I haven't had one go out. In the past, it cost $20-50 to repair one (shipped back to Parmak). The shock it delivers is quite memorable. I believe that it will keep the unwanted critters out. You MUST properly ground the low impedance fence chargers. If you do not, they will blow a fuse. 3 ground rods 10' apart are recommended: this is really important for any of the low impedance fencers.
Maybe you can find a used one on eBay or Craigslist. A used working Parmak Super Energizer is better than a $70 fencer from Tractor Supply.