This woman recently won a $4M lawsuit against her power company due to the presence of “stray voltage” on her showerhead. She claims it caused her to experience “nausea, exhaustion and numbness in her limbs .”
I understand the danger of leakage current from ungrounded appliances. Anything above 5 mA or so through the human body is risky territory. But I was not aware that repeated exposure to small amounts of leakage current (the article doesn’t indicate how many milliamps she was exposed to, so I am assuming the current magnitude was small) can cause permanent health problems.
So can these small-magnitude “stray voltages,” while not lethal, cause permanent health problems? Or is it more likely to be woo/nonsense?
Never heard of this problem, but it appears that it happens near substations. I’m not sure why adequate grounding doesn’t fix the issue, but perhaps somebody will pop in to enlighten us.
Maybe the ground nearby is dry and sandy. That can cause grounding problems and lead to minor local voltage buildup. But it should be possible to fix with more robust and deeper grounding equipment.
Also, I would not give too much credence to an article that quotes an “expert” who says electromagnetic fields can interfere with sleep patterns.
I have heard of that lawsuit before and I’ve heard of the problem as well. In some areas the ground doesn’t conduct very well, especially when it is dry. If you have very large voltages present (like in a substation or an industrial location) you can end up with some surprisingly large voltage gradients.
Adequate grounding in some areas can be difficult. They’ve come up with different grounding schemes like Ufer grounds but if the ground in that particular area isn’t very conductive there’s only so much you can do.
No idea about the health side of it. I’d be curious to see some real (i.e. non-woo) cites on the subject.
I would think that substations would have a fairly large grounding grid around them, particularly in low-conductive areas, or that some sort of remedy could be contrived. Soil replacement? Salting of the soil? Some sort of circulating irrigation system?
Total Woo, and only in California.
If she had a true electrical problem, she should be suing the contractor that built the house to begin with, but as typical with out for the money trash, she goes after the largest bank account.
At the fence around the substation that feeds our industrial complex here, there is no measurable elevated EM at 60Hz. I’d bet there was none at her house either, except for that generated within the house.
It is nice to know that courts in the US still aren’t interested in facts.
In order to have electric current flow through her, there must be a voltage between two (or more) points on her body.
If there was a voltage between her shower head and the floor of her shower stall, and she touched the shower head with her right hand while standing in the stall, then presumably current would flow through her body between her right hand and her feet.
If it can be assumed the shower stall was grounded, then I can see how this would happen if the plumbing was not grounded. In which case an easy fix would be to ground the plumbing.
Or perhaps I’m missing something here. I readily admit I don’t know much about ground currents and E fields in the earth.
And of course, there is still my original question: even if a person periodically experiences low-level electric shocks (due to whatever), is there any evidence such events cause long-term or debilitating health problems?
Hmmm. Well perhaps some additional facts would be helpful in this case.
The award was $1M for her problems and $3M punitive damages, courtesy of the jury.
As I understand it, the house was next to a substation that was later enlarged and new transformers were installed much closer to her house.
At 60 Hz, it is not as easy to find true “ground” as it might seem. A simple pole in the ground would not fix the problem as all of the earth around the transformers was at a higher voltage. The Gas company put in an insulating connection to stop stray voltage from entering the house via that connection (think elevated voltage on gas pipe), but because of the voltage potential between different parts of the house, it supposedly did nothing to fix the issue.
What probably should have happened (IMHO) is the power company should have bought the house and mowed it down, instead they chose to take the legal route.
I don’t believe the supposed medical issues, but the proven electrical issues doomed the utility.:smack:
I wonder if there is more to the story.
When I was living in California, the watermain in font of my house blew. The water company diverted the water into the sewer and my toilet started backing up and overflowing with raw sewage. I showed this to the worker and he opened up the berm and my toilet goes back down. The supervisor comes out and tells the worker to rebuild the berm. My tiolet overflows with raw sewage. I tell the supervisor and he says it’s impossible. I show him the overflowing toilet and he says it’s not his fault because it’s impossible that what they are doing is causing my toilet to overflow. I ask him then why does it only happen when they run the water into the sewer and he says it’s impossible. He leaves and the worker opens up the berm and my toilet goes down.
Now let’s say they rebuild the berm and my entire house was flooded with raw sewage. Given the circumstances how much would I win in a lawsuit for damages both cleaning and punitive? Not 4M but I’m sure a hefty sum which would leave the Dope wondering how I won so much for a backed up toilet that the water company insists was not their fault.
Growing up in Wisconsin I remember reading newspaper stories of cows getting zapped (usually non-fatally, but it was detrimental to milk production) by stray voltage which was usually caused by a bad or aging hookup between the power company lines and the barn. I’ve never heard of it being a “city” problem… interesting.
Perhaps you should learn the facts of the case before pronouncing judgement. See the LA Times article.
She was suing the former owner of the house. Yes, SoCal Edison owned the house. Renters had reported electrical problems, but Edison didn’t fix the problems and didn’t disclose them when they sold the house. That looks a lot like they should be liable for problems.
Looks to me like the OP is perhaps thinking that the term ‘stray voltage’ is some very small current flow that perhaps causes damage over the longer term.
Stray voltages simply means flows of current in places where such a thing ought not to be possible. These can be very high voltages and currents and can be lethal.
These things usually happen when earth conductors have high resistances, so current takes path that was not planned or designed for, or you can get stray currents when two separate places become electrically disconnected from each other - for example - in a shower room you would want all exposed metal work such as shower rails and faucets to have the same potential. The usual practice is to ensure this happens by making physical connections to common points - which is called earth bonding. If a fault develops then all such metalwork would achieve the same voltages so it would not be possible to get a shock by touching two pieces of metalwork.
Naturally is the earth bonding becomes damaged then it would be possible for different potentials to arise and hence the risk of shock, these differences might also be called stray currents.
Stray currents can also arise, through inductive effects. I have seen cables in conduits that are completely disconnected at both ends have voltages in excess of 110v induced into them by other live cables that are in the same conduit - and these can give quite a nasty jolt.
As says casdave, it’s a question of getting all possible conductors to a zero potential (equal voltage) throughout the system (and at all times), simple to say, not necessarily to achieve.
European code has been battling since 1974 to get a good result, they have to modify code every 2 years or so after being surprised by unforeseen situations.
A quick example, daddy buys a new electric oven, to put into his new kitchen (up to code), wires it up, it works. Little Camille takes a drink from the outside faucet (on a PE line) standing on moist earth, and gets enough sauce to stop her heart. The oven was faulty, but the nice electrician had put “extra grounding” between the oven box and the water mains, which somehow circumvented the breakers. Camille was on her feet a few hours later after a good scare and a good hospital.
Grounding is pretty easy to test, an ohmmeter with a long wire, just check that anything that looks conductive gives a 100% conduction with the main ground (or eventually the water mains) anything else, or any “tingling” feeling on something merits a call to a qualified electrician