Opinion ID: 2521574
Heading Depth: 1
Heading Rank: 6

Heading: Electrical Current

Text: [¶ 22] Creating an electric circuit is a function of force which is measured in voltage, current which is measured in amperes, and resistance which is measured in ohms. [1] Simply stated, electricity involves the flow of energy (electrons) along the path of least resistance toward a natural ground. See Schlader v. Interstate Power Co., 591 N.W.2d 10, 12 (Iowa 1999); see also W.B. Saunders, Nave & Nave Physics For the Health Sciences, Electric Shock Hazards ch. 14 (3d ed.1985). All objects are either resistors or conductors. The electric current is the most important physiological variable for determining the severity of an electric shock. However, this current is in turn determined by the driving voltage and the resistance of the path that the current follows through the body. A voltage that produces only a mild tingling sensation under one circumstance can be a lethal shock hazard under other conditions. This uncertainty is caused because although the skin acts as a natural resistor to flow, i.e., normal skin has a resistance of 25,000 ohms and calloused skin has a resistance of 2,000,000 ohms, wet skin has a resistance of only 1,500 ohms. One hundred and twenty volts delivered to a calloused finger would probably cause a tingling sensation, that voltage delivered to dry skin would cause a painful shock, but that same voltage to wet skin could prove to be a lethal shock. Id. [¶ 23] The record shows that when electricians measured voltage in the areas where Easum was working, their readings were consistently between thirty and fifty volts, with the highest reading at sixty-seven volts. The resistance is unknown as is the level of current; however, Easum stood in water and placed his hands in water so presumably resistance was low. As we have already seen, the margin between a minor shock with no effect and electrocution is very narrow. The issue of stray voltage in connection with dairies and the effect on dairy herds is not new to courts and is explained as follows: All electricity leaving an electrical substation must return to that substation in order to complete a circuit. Unless that circuit is completed, electricity will not flow. The current leaves the substation on a high voltage line which eventually connects to some electrical `appliance.' After exiting the `appliance' that current must return to the substation. The neutral-grounded network provides the returning current two choices. Either it can return via the neutral line, which accounts for the second wire on our electrical poles, or it can return through the ground. These two pathways comprise the grounded-neutral network. Electricity flows through the path of lowest resistance. If there exists more resistance in the neutral line than in the ground, the current will flow through the ground to return to the substation. Neutral-to-earth voltage or stray voltage will occur when current moves from either the neutral line to the ground or from the ground to the neutral line. It uses a cow as a pathway if that animal happens to bridge the gap between the two. A cow's hooves provide an excellent contact to the earth while standing on wet concrete or mud, while at the same time the cow is contacting the grounded-neutral system consisting of items such as metal stanchions, stalls, feeders, milkers, and waterers. The current simply uses the cow as a pathway in its eventual return to the substation. Apparently very slight voltages can affect cattle. Evidence [has] suggested anything greater than one volt can be catastrophic to a dairy farm. Kaech v. Lewis County Public Util. Dist., 106 Wash.App. 260, 23 P.3d 529, 533 n. 3 (2001).