The wire configuration on the fences varies with the paddock's usage, if you just want to keep sheep in, three or four wires will do, but for predator control Gallager, who make electric energisers, recommend an earth wire 2" above the ground, live 4" above that, earth 4" above, live 6"" above, and so on.
We built a lambing paddock like this near the house and for the first few years it worked very well and we didn't lose many lambs to foxes. In the last couple of years we have found that the foxes are coming in more often, maybe they have learnt the fences weak spots, or they learn to move quickly through the fence and only get a shock occasionally. Hunger is a great motivator. The plain wire also makes it easier to get the carcase out of the paddock. So when we needed a lambing paddock on the other block Electric Fence #2 was developed.