dwm@msc.edu (Don Mears) (04/09/91)
Can someone explain what they were talking about on 60 minutes on 4/7 in the piece on stray voltage from old power lines that caused dead and deformed animals, and shocks to people? These did not look like high voltage power lines, just normal ~10kv distribution lines. The information was presented as though it was all black magic with no scientific explanations. A format usually reserved for nuclear issues. The problem must be related to insulator breakdown somewhere or power radiated from power lines through the air to other structures. I don't understand why it is not trival to measure. I don't understand why the farmers involved can't circumvent the problem with additional shielding, grounding, or insulation. I don't understand why replacing the just power lines without rerouting them fixes the problem. I believe that this problem exists, but the 60 Minutes presentation made no sense to me. dwm@msc.edu Donald W. Mears @ Minnesota Supercomputer Center
rick@ee.uwm.edu (Rick Miller) (04/09/91)
I'm an engineer at WEPCo, and it just so happens that I work right next to our stray-voltage expert (Chuck DeNardo). It also happens that I know a little something about electricity (it helps, being an EE). Stray voltage is a detectable (3 micro-volts up to half a volt) voltage gradient in the ground which may cause irritation to farm animals when they are hooked up to milking machines or feeding out of metal troughs that are grounded more than a few yards away. Stray voltage occurs NATURALLY as well as being a result of poor wiring (usually an un-grounded neutral in the farm's own wiring). Basically, it can make a cow not like to eat out of a trough or not want to give milk (because it tickles), but THERE ARE NO ANIMALS EXPLODING BECAUSE OF STRAY VOLTAGE!!! more later...
bender@oobleck.Eng.Sun.COM (I want to be eating rich soup in another town) (04/09/91)
In article <10868@uwm.edu> rick@ee.uwm.edu (Rick Miller) writes:
->
-> I'm an engineer at WEPCo, and it just so happens that I work
->right next to our stray-voltage expert (Chuck DeNardo). It also happens
->that I know a little something about electricity (it helps, being an EE).
->
-> Stray voltage is a detectable (3 micro-volts up to half a volt)
->voltage gradient in the ground which may cause irritation to farm animals
->when they are hooked up to milking machines or feeding out of metal troughs
->that are grounded more than a few yards away. Stray voltage occurs NATURALLY
->as well as being a result of poor wiring (usually an un-grounded neutral
->in the farm's own wiring).
-> Basically, it can make a cow not like to eat out of a trough or
->not want to give milk (because it tickles), but
-> THERE ARE NO ANIMALS EXPLODING BECAUSE OF STRAY VOLTAGE!!!
Hey, this sounds like perfect stuff for alt.folklore.urban:
"Farmer's Cow EXPLODES, farmer claims STRAY VOLTAGE,
Russian experts testify to existance of space aliens
that EAT stray voltage..."
or something like that...
mike
--
Won't look like rain, Won't look like snow, | DOD #000007
Won't look like fog, That's all we know! | AMA #511250
We just can't tell you anymore, We've never made oobleck before! | MSC #298726lewis@tramp.Colorado.EDU (LEWIS WILLIAM M JR) (04/10/91)
In article <10868@uwm.edu> rick@ee.uwm.edu (Rick Miller) writes: .... >... Stray voltage occurs NATURALLY if the power company fails to keep the load on the two legs balanced >as well as being a result of poor wiring (usually an un-grounded neutral >in the farm's own wiring). More likely the reluctance of the power company to replace old wiring that can't handle the load.
rick@ee.uwm.edu (04/10/91)
> lewis@tramp.Colorado.EDU (LEWIS WILLIAM M JR) writes: >In article <10868@uwm.edu> rick@ee.uwm.edu (Rick Miller) writes: >>... Stray voltage occurs NATURALLY >if the power company fails to keep the load on the two legs balanced >>as well as being a result of poor wiring (usually an un-grounded neutral >>in the farm's own wiring). >More likely the reluctance of the power company to replace old wiring that >can't handle the load. I've got a book (_Collier's Cyclopedia of Social and Commercial Information_) published around 1896 that describes how to get your pigs to drink out of a tin trough... Ground it. Tin troughs typically rested on wooden frames with a metallic water-pipe leading from the windmill several yards away. The pigs standing in the mud by the trough didn't appreciate the 50 mV or so that was tickling their snouts as they drank... and this was nowhere near ANY power lines. As for the "old" lines... A power company's responsibility for old wiring ends at the meter. Almost all stray voltage problems are due to poorly- wired barn circuits. And unless a farmer is using more amperage than his (or her) service is rated for, the imbalance caused by line reluctance will be negligible compared to the imbalances caused by the loads he/she puts on their circuits (which are, by the way, rarely in perfect balance and almost never under power company control). Lines are built to last a LONG time. ========================================================================== These are MY statements, not those of my employer nor of Wisconsin Energy. Rick Miller, Meter Applications Engineer, WEPCo rick@ee.uwm.edu
dgustafs@eecs.wsu.edu (gustafson david s - CS350) (04/11/91)
In article <10917@uwm.edu> rick@ee.uwm.edu writes: >As for the "old" lines... A power company's responsibility for old wiring >ends at the meter. Almost all stray voltage problems are due to poorly- >wired barn circuits. And unless a farmer is using more amperage than his >(or her) service is rated for, the imbalance caused by line reluctance will >be negligible compared to the imbalances caused by the loads he/she puts on >their circuits (which are, by the way, rarely in perfect balance and almost >never under power company control). Lines are built to last a LONG time. I whole heartedly agree. I grew up on a diary farm (not too many years ago) and I can attest to the poor state of wiring on most dairy farms. The milking barn is wet and filled with corrosive elements; most electrical installations are not protected well enough. Even if the inital installation is done correctly, there are allways modifications that are below code. Even on a modern farm (10 years old), I have felt leakage current on several occasions; a result of broken or worn insulation conducting through the stantions. If I can feel it, certainly the cows can. We now have a meter installed that will detect stray voltage between the stantions and earth ground. Dave -------------------------------------------------------------------------------- David Gustafson - EECS Washington State University - dgustafs@yoda.eecs.wsu.edu --------------------------------------------------------------------------------
john@newave.UUCP (John A. Weeks III) (04/11/91)
In article <3853@uc.msc.umn.edu> dwm@msc.edu (Don Mears) writes: > Can someone explain what they were talking about on 60 minutes on 4/7 > in the piece on stray voltage from old power lines that caused > dead and deformed animals, and shocks to people? These did not look like > high voltage power lines, just normal ~10kv distribution lines. I did not see the 60 minutes piece, but there are major problems with stray voltage in Wisconsin on some farms. What the farmers know is that milk production and life spans of animals drop and the deformity rate of calves increases after some electrical change was made. Some are related to transmission lines, other cases relate to electrical wiring problems. Many cases remain unsolved. If you have ever seen the inside of a cow barn, you will remember a lot of pipes running around. There are piping systems for vacume (to power the milking equipment), water (for drinking water), milk (lines to the bulk tank), and pipes to seperate the cows. Some barns also have "training wires" (a low strung wire carrying current that the cow would contact and get zapped on if it tried to go to the bathroom in the stall--cows are supposed to back up & go in the gutter, which is lower, thus no zap) and automated feeders. All of these devices are big electrical conductors. Most are grounded only at one point. Thus, there is the potential for large ground loops if the metal pieces are not grounded at the same spot. Any type of electric current that gets into the system can cause stray voltage problems. This current can be natural. Some folk tales blame the problems on the rebar rusting in concrete floors. > The problem must be related to insulator breakdown somewhere or power > radiated from power lines through the air to other structures. I don't > understand why it is not trival to measure. I don't understand why > the farmers involved can't circumvent the problem with additional shielding, > grounding, or insulation. I don't understand why replacing the > just power lines without rerouting them fixes the problem. The cases that can be measured are easy to fix. Usually the voltage is usually very small, often less than 0.5 volts and as high as 1.75 volts. But the cases that cannot be measured or isolated are very difficult to fix. Wisconsin Public Service and other utilities have programs to help out farmers that can demonstrate a problem. The utility companies and some have spent large sums of money trying to fix these problems, often unsucessfully. If you want more information, try writing to one of the power companies in Wisconsin. Try Wisconsin Public Service, Dairyland Power Cooperative, or Wisconsin Power & Light. -john- -- +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ John A. Weeks III (612) 942-6969 john@newave.mn.org NeWave Communications ...uunet!tcnet!wd0gol!newave!john
rbrink@hubcap.clemson.edu (Rick Brink) (04/16/91)
From article <746@newave.UUCP>, by john@newave.UUCP (John A. Weeks III): > In article <3853@uc.msc.umn.edu> dwm@msc.edu (Don Mears) writes: >> Can someone explain what they were talking about on 60 minutes on 4/7 >> in the piece on stray voltage from old power lines that caused >> dead and deformed animals, and shocks to people? These did not look like >> high voltage power lines, just normal ~10kv distribution lines. You don't have to go to the cow barn to find stray voltage. I did some electrical repair work in a vegtable packing house here in South Carolina. While installing some new equipment, I got several good "bites" from the frame of a conveyer. I started checking around....I found the closest true ground in the system, at the pole outside! None of the equipment was frame grounded or cross grounded. The whole system relied on the neutral (in the single phase circuits) nothing in the 3phase circuits. It seems the the whole system was homegrown, and had origionally been grounded to the building rebar. But someone had knocked the ground strap loose with a forklift sometime ago... Only pure luck saved lives there. With all that running water, and the overloaded motor circuits poping breakers, it was a disaster waiting to happen. The worst part of it, was the additions done to the origional circuits by several licensed contractors, without ever checking the safty of the system. I was just repairing some small gearmotors next to the line afterhours when I discovered it.
stevek@locus.com (Steve Krattiger) (04/18/91)
In article <1991Apr15.172627.13060@hubcap.clemson.edu> rbrink@hubcap.clemson.edu (Rick Brink) writes: >From article <746@newave.UUCP>, by john@newave.UUCP (John A. Weeks III): >> In article <3853@uc.msc.umn.edu> dwm@msc.edu (Don Mears) writes: ->> Can someone explain what they were talking about on 60 minutes on 4/7 ->> in the piece on stray voltage from old power lines that caused ->> dead and deformed animals, and shocks to people? These did not look like ->> high voltage power lines, just normal ~10kv distribution lines. - -You don't have to go to the cow barn to find stray voltage. I did some -electrical repair work in a vegtable packing house here in South Carolina. -While installing some new equipment, I got several good "bites" from the -frame of a conveyer. I started checking around....I found the closest true A few years back, a friend and I were in a Straw Hat Pizza Parlor and discovered two pinball machines sitting next to each other that were "hot". I don't think that 'stray voltage' was the problem here, but more likely a faulty ground on one of the circuits, or incorrect wiring... We had a lot of fun with it.... :-) +-----/\/\/\/--------||--+---->|---|---/\/\/\/--------/\/\/\/-------|<--------+ | Steve Krattiger |-/\/\/\--| Locus Computing Corp. .. | | stevek@locus.com === Los Angeles, California \/ | +----|(---------/\/\/\/----|<------|------|+|+|+-------)|-----/\/\/\/----||---+
tonyb@titania.juliet.ll.mit.edu ( Tony Berke) (04/18/91)
In article <1991Apr15.172627.13060@hubcap.clemson.edu> rbrink@hubcap.clemson.edu (Rick Brink) writes: From article <746@newave.UUCP>, by john@newave.UUCP (John A. Weeks III): > In article <3853@uc.msc.umn.edu> dwm@msc.edu (Don Mears) writes: >> Can someone explain what they were talking about on 60 minutes on 4/7 >> in the piece on stray voltage from old power lines that caused >> dead and deformed animals, and shocks to people? These did not look like >> high voltage power lines, just normal ~10kv distribution lines. You don't have to go to the cow barn to find stray voltage. [more...] I have an interesting addition to this... I have some friends that live near some big voltage lines in Mason, NH. They have a fiberglass hot-tub sitting on a cement slab. One day I was halfway into the tub, with one foot on the slab and one in the water, when I recieved a pretty healthy zap. This happened to enough people that an electrician was called in, and it was eventually determined that the tub was floating, electrically, at some distance above ground, and the potential in it was getting there do to some potential gradient (in the soil?) coming from the power lines. This sounds like 'stray voltage' to me, but I still don't quite understand the mechanism. P.S. Ironically, these people own a veal farm. Perhaps stray voltage is actually creating in dung-heaps? (A voltaic pile, as it were). -Tony (tonyb@juliet.ll.mit.edu)
rambler@pnet51.orb.mn.org (Dan Meyer) (04/23/91)
tonyb@titania.juliet.ll.mit.edu ( Tony Berke) writes: >In article <1991Apr15.172627.13060@hubcap.clemson.edu> rbrink@hubcap.clemson.edu (Rick Brink) writes: > > From article <746@newave.UUCP>, by john@newave.UUCP (John A. Weeks III): > > In article <3853@uc.msc.umn.edu> dwm@msc.edu (Don Mears) writes: > >> Can someone explain what they were talking about on 60 minutes on 4/7 > >> in the piece on stray voltage from old power lines that caused > >> dead and deformed animals, and shocks to people? These did not look like > >> high voltage power lines, just normal ~10kv distribution lines. > > You don't have to go to the cow barn to find stray voltage. [more...] > >I have an interesting addition to this... > >I have some friends that live near some big voltage lines in Mason, >NH. They have a fiberglass hot-tub sitting on a cement slab. One day >I was halfway into the tub, with one foot on the slab and one in the >water, when I recieved a pretty healthy zap. This happened to enough >people that an electrician was called in, and it was eventually >determined that the tub was floating, electrically, at some distance >above ground, and the potential in it was getting there do to some >potential gradient (in the soil?) coming from the power lines. This >sounds like 'stray voltage' to me, but I still don't quite understand >the mechanism. > >P.S. Ironically, these people own a veal farm. Perhaps stray voltage >is actually creating in dung-heaps? (A voltaic pile, as it were). > >-Tony (tonyb@juliet.ll.mit.edu) It is much more likely that your friends have a defect in the water filtration/heating system for their hot tub. Since you did not pick up on this, I suggest that you have them call an electrician to find and repair the problem in their equipment. -- Dan Remember: " Buffalo never Oink " Seen on a South Dakota travel brocure. Advertisment: Try the Railway Post Office , a railfan BBS ! (612) 377-2197. UUCP: {crash tcnet}!orbit!pnet51!rambler INET: rambler@pnet51.orb.mn.org