Mad Cows

[bennie]

I have been reading that the State of Wisconsin has ruled in favor of the cows over the old stray voltage phenomenon.

I would like to see Charlie's take on this subject.

[tom baker]

last fall I had a conversation about stray voltage with a wisconsin utility engineer. Its a very big problem, often the utility will have a contractor reqire a barn to solve the stray voltage issue, as farm wiring is frequently not to code.

[bennie]

Tom: The article is in the latest edition of the EC&M Magazine. The State Supreme Court ruled in the favor of the dairy owner, and against the power company.

I would like to read the trial transcript.

[tom baker]

Here is the link to the article
http://ecmweb.com/ar/electric_wisconsin_utility_found/index.htm

[don_resqcapt19]

Bennie,
Here are links to the Court of Appeals Opinion (http://www.courts.state.wi.us/ca/opinions/00/pdf/00-2703.pdf) and the
Wisconsin Supreme Court opinion (http://www.courts.state.wi.us/sc/opinions/00/pdf/00-2703.pdf) in this case.
Don

[russellroberts]

I've read that some maintain the primary and secondary neutral tie is the culprit in some of these cases. Any opinions?

Russell

[bennie]

Russell: Don't mention that :( ...Soares grounding book says there is no electrical connection between the primary and secondary of a transformer. That is why it is a separately derived system.

A real separately derived system will prevent earth current flow. This is why the utility neutral must be disconnected from the premises wiring.

[bennie]

Russell: The utility companies call the system of electrically connecting the primary to the secondary a MGN system.

The NEC experts call this a separately derived system. Go figure :D

[russellroberts]

According to Merriam-Webster, Seperate means to set apart.Synonyms are disconnect and sever. :roll:

Russell

[bennie]

That is correct. The meaning is electrically separated from the other power supply.

The opposite of...Electrically connected, means to be capable of carrying current as opposed to magnetic coupling.

[hornetd]

So What is the upshot of the circuit courts reconsideration of the nature of the injunctive relief that it ordered? Did WEPCO have to provide an overhead ungrounded delta system or didn't it? This is not idle curiosity here. I am much more interested in what works then in who won. I tried and failed to get an ungrounded secondary transformer installed to supply a client dairy farmer. I ended up moving the electrical service point to the property line to make the grounding of the neutral as remote as possible from the dairy buildings. I ran an overhead four wire single phase feeder system to all buildings on the farm and I put main bonding jumper current detection at the service. The detection will sound an alarm if any measurable current flow occurs thus allowing the rancher to switch to a power take off generator that is a true separately derived system. When we did this the last time that they had problems the erratic dairy heard behavior stopped.
--
Tom

[ July 12, 2003, 03:40 PM: Message edited by: hornetd ]

[bennie]

Tom: The utility company will not supply a delta ungrounded secondary except for special purposes. The special purpose is when a winding to winding fault, in the transformer, will not be a hazard.

With the MGN system, fault, and load current, from a downwind service can appear on the dairy service even when off.

[hornetd]

Bennie
I did a google search and read ten differrent articles on dairy farm stray voltage.
Several articles mention isolation transformers. I can't figure out a code compliant way to install an isolation transformer. If I do figure out a code compliant way to install them so that they will pass inspection based on the US NEC then I can make some serious money installing them. One farmer went to on farm generation and his increased production more than paid for the cost of running the generator.
--
Tom

[bennie]

Tom: I would like to buy stock in your company. I like milk :cool:

Look in the 1984 edition of the handbook, if you have one. The drawing of a separately derived system is shown as one with an ungrounded primary supply. There was no electrical connection between the primary and secondary.

Someone came along after McPartland and drew in the equipment grounding on his drawings. This caused the definition of a separately derived system to go sideways.

This is why I say there is no such thing as a transformer source for a separately derived system. I have all the technical and engineering documents to substantiate my stand on this issue.

This misinterpretation should be corrected.

A separately derived system is a premises wiring system supplied with an ungrounded primary and a grounded secondary transformer source.

An isolation transformer is one with a grounded primary and an ungrounded secondary.

[bennie]

An ungrounded 480 system is supplied by a grounded 480 secondary to the primary of the end user transformer.

The transformer is a delta/delta 480/480 This is due to the possibility of an arc through from primary to secondary. The fault will not open the cut outs until it becomes a LL fault, but will show on the ground detector alarm or lights, plus you can trace the smoke.

[ July 12, 2003, 11:10 PM: Message edited by: bennie ]

[charlie]

Originally posted by Bennie:
I would like to see Charlie's take on this subject.I'm back. :D With my hard drive crash and the power outages from the storms that went through, I have not been able to be involved. With all that said, I will not comment on any subject on stray voltage in writing while I am still working. I will be happy to give my opinions verbally if I am at an IAEI meeting or something like that. Sorry, Charlie ;)

[bennie]

Charlie: I was beginning to think you crashed.

I recently upgraded my computer. I am learning how to edit and produce movies from a DV Camera.
They require a lot of disc space.

I now have 112 GB hard drive space and 640 MB RAM.

I can understand your reluctance to print any thing about a subject that could have legal repercussions, considering your position.

I lost my job, as an inspector, by expressing my concern about EMF and energy fields, over a children's playground, due to high voltage transmission lines. The local TV station made me famous for 2 minutes :eek:

Good to see you are OK. Your knowledge of both inside and outside work is valuable to this forum, and to the NEC.

[karl riley]

Bennie, I would like to hear more about this (losing job because of opinions about EMF over child playground). When I was in California I was called in to measure fields from just such a situation in Marin County. PG&E was cooperative at that time, the press was on the side of the school, and so PG&E raised and reconfigured the transmission line over the playground to bring the fields down to 1 mG. They also changed a spread-out service drop that looped over a classroom to triplex configuration, which reduced the field to insignificant.

I had other friendly interactions with PG&E as well as So Cal Edison and also got a reconfiguration (reverse phasing)of the phases on a transmission line impacting a software company.

Some other utilities were more into stonewalling. It depended partly on who you spoke to. But the propaganda war goes on and sometimes one side has the press with it and sometimes the other. At this time California law specifies a setback for schools from differnt power lines.

When were you involved?
Karl

[karl riley]

Tom, I think your solution of putting the SE point on the edge of the property and running 4-wire is the best solution I have heard of yet, and will recommend it in the future. Then the farmer just has to clean up his wiring and make sure he doesn't have neutral running around on metal stalls, etc.

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.
Karl

[bennie]

Karl: There is a utility easement corridor running from Washington State, through Oregon, into California.

This corridor has iron maiden towers for 230 KV lines, and wooden structures for 138 KV lines.

There is also, in the ground, a gasoline pipeline from California to Washington. This is the same line that killed two boys, in Washington, when the line leaked and gas spread in the stream where the boys were wading. The gas was ignited and the explosion killed the boys.

I call this setup "The corridor to Hell"

I went on record about a childrens play area being erected under the lines. The kids were actually getting a slight shock when touching the structure.

The builder/developer of a lot of high end homes bordering this corridor, protested to the community I was working. He was also the builder of the playground. The property owners and parents of the children had the playground moved to a greater distance, partly based on my statements.

This builder had a lot of political clout. I was a contract inspector, and my contract was not renewed. The reason given to me was that I was under bid for the position. I found out the replacement was charging ten dollars per hour more than I was.

I was informed by a credible source that the city officials were upset over my statement "I would not let my grandkids on that playground"

This statement appeared in the Oregonian newspaper and was on camera, with me saying it on TV.

[ July 13, 2003, 03:19 PM: Message edited by: bennie ]

[don_resqcapt19]

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]

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]

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]

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 (http://www.bpu.state.nj.us/wwwroot/energy/strayvoltsum.pdf)
Bass Enginering Document (http://www.bpu.state.nj.us/wwwroot/energy/strayvoltsum.pdf)
Testomony in Michigan Consumer Power Law Suit (http://www.ag.state.mi.us/speclit_div/speclit_hm.htm)

Don

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

[charlie]

Don, :D Charlie

[karl riley]

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]

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 :eek: , 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]

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