Mad Cows

[don_resqcapt19]

Re: Mad Cows

Tom,
The Wisc. case was just remanded to the lower court at the end of June. I doubt that there is a final resolution at this time.
Don

 

[don_resqcapt19]

Re: Mad Cows

Karl,

Then as long as primary neutral is not coursing thru the farm because it has found a short cut back to the substation, the farm should be clear.

It is my understanding that many times the primary neutral is too small and when it is connected to a grounding electrode at the farm service, some of the primary neutral current will flow through the earth and may cause problems for dairy animals.
Don

 

[charlie]

Re: Mad Cows

Don, think about the number of ground rods, well casings, tanks, antenna foundations, etc, that are in parallel with the MGN. Then think about the MGN being solidly bonded to the grounded conductor that feeds the service. How much does the size of the MGN have much to do with the return current?

Sorry, I am just thinking and asking questions, I can't answer them.

 

[don_resqcapt19]

Re: Mad Cows

Charlie,
With all of those parallel paths through the earth some of the current will be flowing on the earth back to the source and not on the primary grounded conductor. Some of the problems with dairy cows is said to be caused by the primary grounded conductor current flowing through the earth.
Look at these documents:
a New Jersy stray voltage case
Bass Enginering Document
Testomony in Michigan Consumer Power Law Suit

Don

[ July 14, 2003, 12:18 PM: Message edited by: don_resqcapt19 ]

 

[charlie]

Re: Mad Cows

Don, Charlie

 

[karl riley]

Re: Mad Cows

Don, studies have shown that up to 50% of the primary neutral flows through the earth paralleling the lines. This would affect a dairy farm only if there is an electrical reason for the current to divert through the farm. This might exist if the primary makes a loop around the farm and conditions are such that some of the neutral in the earth finds a competing low impedance path through the farm. I am told that reactance tends to keep the flow under the lines, but I have never studied reactance enough to have an opinion.
Karl

 

[bennie]

Re: Mad Cows

Karl: Analyze this hypothesis...A distribution transformer in front of a farm property, pole butt ground electrode.

Behind this farm is another one. The MGN is again earthed. The dirt between these farms is saturated with bovine urine , a very good conductor. The primary load current, on the second farm, will flow through the one in question.

This low impedance path will follow the cows from the pasture to the milking area.

[ July 15, 2003, 03:54 PM: Message edited by: bennie ]

 

[karl riley]

Re: Mad Cows

Bennie, I could see that happening. It would be better if the cows pissed on the pole ground rod, though, since that is where the impedance is, not in the earth itself (I have been told).

Karl