Jim62":38wv7jxf said:
Thanks! I wound up using 3 8' copper (coated ?) rods. Checked voltage before and after. Had right at 6,000 with both ground systems (barn and ground rods), so no big difference there. Lightening choke is next.
Just out of curiousity, why do we use INSULATED ground wire? The power company's grounds are not insulated.
As I believe several people have said, the voltage may be there but it takes a good ground to give the animal (or you touching it) the amps to give a real shock. There are various high voltage toys and tricks that put on fancy displays but don't give you much shock because there is no current flow.
When an animal touches the hot wire, current flows across the hair coat through the body and to the ground. If the current is not sufficient or the ground is not good even high voltages do not produce enough current across the haircoat, hooves, grass, possibly dry ground and all the way back to the fencer ground rods to complete the circuit.
Completing the circuit is what gives the animal the shock. The better the grounding system, the more likely the circuit will be completed well enough to make the animal remember not to do it again.
As fas a s why use insulated wire for the ground connection, it really is not necessary to do so. Some folks use #12 fence wire for the grounds. I use insulated 12 ga underground wire for my grounds because it is usually in the same trench as the hot wire for at least part of the run and having two insulated wires reduces the chance of a short between them. The good under ground wire such as the Gallagher is also very well galvanized. Grounds should be galvanized, not copper rods as used in household electrical systems.
Corrosion can be a problem and on outdoor systems like fence grounds, good galvanized wire clamped to well-galvanized ground rods with either brass or galvanized clamps will have less chance of losing connection due to corrosion over the years. Copper does corrode over time. If you use copper ground rods you should check the contact points to the wire every couple years and clean with sandpaper etc. It is probably not worth taking copper rods out but the connection contact point between the zinc galvanizing and the copper rod can be a source of what's called galvanic corrosion.
Power company pole ground wires are copper but do not connect to a ground rod. They extend into the soils and usually wrap around the bottom of the pole. These are for lightning usually and there is enough juice in that wire there is no trouble crossing over to ground!
Jim