Awhile ago, we had a bad storm here and our basement flooded. Unfortunately, this is not that unusual an occurance. My brother, in his not-too-clearheaded-state, thought “Oh shit, we have a lot of electrical appliances down there, we should unplug them.”
So he takes off his shoes, socks, and goes barefoot into the just-over-ankle-deep water :smack:
Nothing happens. He goes over to the powerstrip, which is submerged and has four appliances connected to it, and whose red power light is still on, and unplugs it from the wall. Then it dawns on him, “wait a sec. I wasn’t supposed to do that.”
For the life of us, we can’t figure out why he hadn’t been shocked into the kingdom come that night. The power was on, the circuits hadn’t broken, the light on the power strip was freaking on!
Obviously, there was no path to ground through him. In order to get a shock, current has to flow through yoru body. Merely contacting a voltage source will not necessarily shock you. Linemen make use of this fact when repairing live high-voltage transmission lines. As long as there is no path to ground through the lineman’s body, he can safely hold on to a wire energized with 750,000 V or more.
Well, it wasn’t a very wise, or safe thing to do. However, when he stepped into the water he assumed the same voltage as the water. Apparently it wasn’t too different from the voltage at which his body already was. As long as he didn’t touch anything on the way to the power strip he was OK and as long as the power cord insulation was intact he could pull the cord without a shock.
The light was still on because the water apparently didn’t have enough conductivity to allow enough current to blow the breaker.
Tell him not to do that again. Go to the breaker panel and turn off all basement power.
Assuming all the fuses or circuit breakers were functioning properly, then yeah - there must have been a ground fault somewhere. That is, the electricity was never given a short circuit path directly to ground. This would have tripped any self-respecting fuse or circuit breaker pretty quickly. How a short circuit didn’t happen in the circumstances you describe is quite a mystery.
However, assuming that the water was energized, it is conceivable that he could have ran that gauntlet without turning his skull into a human Van de Graff machine. Think of him as a bird on a wire. Birds land on live, uninsulated lines all the time because they do not provide a path to ground. The electricity would rather just go where it is going. But if you get a really big bird, like an eagle, whose wingspan can bridge between two wires, well - that would close a circuit and our grand bald eagle would go up like the rocket’s red glare. Similarly, if your brother had touched a properly grounded appliance while standing in energized water, he would have completed the circuit to ground and set in motion the beginnings of a very bad day. Until the circuit breaker shut off the power.
If none of that happened, then you might consider having someone take a look at your house’s electrical system. It may be deficient in some very necessary safety features. And, if I remember correctly, the GFCI outlets in the basement is an NEC requirement, not just a local one. Its requirement in your house may or may not be subject to a grandfather clause. But don’t quote me on that one…
For what it’s worth, I did that a few years ago as well. My office had been flooded with water backing up from the storm sewers, and the whole office was in about 3" of water. The difference was that I was in leather shoes, and when I reached down to grab and then unplug a submerged powerstrip, I did get a slight “zap” - more like a strong tingle than anything else, but still a “wtf am I doing?” wakeup call. Of course, I ignored that and waded through the rest of the office to be sure important stuff was off the floor… :smack:
Not necessarily. Fuses and circuit breakers respond only to current overages on the hot leg. They don’t care if there is an errant path to ground as long as the current flow is less than their trip rating. This is why GFCIs (Ground Fault Circuit Interruptors) were designed. GFCIs detect and respond to differences between the current in through the hot leg and the current out through the neutral. If the imbalance amounts to, typically, more than 5 mA, the GFCI trips and cuts off the flow of current. This is important, since currents as low as 100 mA flowing through the wrong parts of your body can cause death.
I think what you’re saying is “assuming that the hot side of the power strip was in electrical contact with the water…,” but if it were in contact, why would the neutral side not be, and then blow the breaker?
I think the mystery here is why the submerged power strip didn’t blow the breaker, not as much why your brother survived.
I am sorry but I don’t get it. The OP says his brother walked on the ground with his feet submerged in water. That is not the same as a man touching a hi tension wire and nothing else, or a bird perched on a cable and neither get electrocuted. In the OPs case, why woudn’t the current flow from the outlet to the legs and into the ground? People do get electrocuted if they are in a tub and a hair dryer falls in. How is the OPs case any different in principle. Agree that the volume of water we are talking about is large, but it is like a person in a large tub the size of a basement. Will a hairdryer falling in that large tub not have the same fatal effect?
Since the water is also in contact with the floor, then the electricity would have already been flowing directly there itself without needing to flow through the brother.
In a small enclosure like a tub, your body will be in the path of more of that electricity as it’s trying to get to ground, so the size of the container makes a big difference.
I think part of the issue is that water is not that good of a conductor. Water will make a human a good enough conductor to kill him, but there obviously wasn’t enough current flowing through the water to trip the circuit breaker (it certainly would/should have trip a GFI, which it sounds like you need).
Also in order to get shocked the electricity would need to flow through him. If he grabbed the insulated plug of the power strip (above water) and unplugged it, there wouldn’t be any current flowing through his body.
He probably would have been shocked if he had reached down and messed with the power strip while it was under water.
Really though, if your basement floods and you have electrical equipement down there you really need to have GFI outlets or breakers installed. I’m pretty sure its code in new construction, and its a really good idea for everyone with a wet basement.
Don’t worry. I think he realized his mistake — he is 22, after all. But our breakers — actually, we have fuses — are in the basement, which would make cutting the electricity a mite bit difficult at any rate.
So, simplify for me for a bit…what’s the difference between this, and the whole toaster-in-the-bathtub snap-crack-pop routine? I do understand that water is not a particularly good conductor in and of itself, but with all the much and dissolved salts in the water, there would plenty to carry a current, right? So it’s all a matter of grounding? I thought about this, but wouldn’t he have been grounded standing barefoot on the floor?
Anyhow, what different principles apply with the bathtub example versus this? Or am I wrong? A toaster in the bathtub might not actually light you up?
The bottom line is that, in order to get zapped, there must be a sizable voltage (over 40 V or so) between two points on your body.
If the water in the basement was a half-way decent conductor (which it would be in the likely case it contained disolved minerals and other impurities), and electrical equipment was submersed in it, there would exist an “electrical current density” in the water. This also means there would exist voltage gradients in the water. If the voltage gradients are relatively small in magnitude then you probably won’t get zapped, regardless of the amount of current flowing through the water. In this case, the more conductive the water, the better (i.e. safer).
By far the most dangerous scenario is when you’re standing in water and you reach for an electrical appliance through the air. This is bad[sup]TM[/sup] because you’re grounded very well when standing in water, and the electrical appliance is 120 VAC (with a peak of 170 V) relative to earth ground.
I’m not an expert in the electrical appliance dropped into the tub routine. I’ve always wondered if it is a lethal as the movies make out. Not that I recommend it you understand, in fact I strongly advise against it.
The problem with electrical appliances and bathtubs, in my view, would be having one, say a cheap AC operated radio, hair dryer, etc., near enough that you can reach it while in the tub. If the device happens to have an accidental leakage path from the line to the outer chassis you’re probably cooked.
In fact this also holds true for appliances and any water, like wash basins or standing water. That’s why the electrical code now requires ground fault interrupters in bath rooms, basements, garages and exterior outlets. If appliances do happen to have an accidental leakage path, the GFI will turn off the power and keep doing it until the offending device is disconnected from the line.
And even with the bathroom outlets protected by a GFI it is still a bad idea to have appliances within reach of the tub or shower because GFIs can also fail. That’s why there’s a TEST button on them. It should be checked regularly.
[QUOTE=pulykamell]
Don’t worry. I think he realized his mistake — he is 22, after all. But our breakers — actually, we have fuses — are in the basement, which would make cutting the electricity a mite bit difficult at any rate.
I reccomend that you check your fuses, in case somone in the past put a penny or other conductor behind the fuse. People used to do that sort of thing when a certain fuse would burn out a lot. Really bad idea. Just make sure you kill the main power before you check. Better yet, call and elcetrician.
Sounds like you house is in need of an electrical ovehaul.
[hijack] The GFCI in my bathroom trips all by itself when I plug anything into the bottom outlet (but not the top one). If I reset it with the appliance still plugged in, it stays reset and the appliance works. Should I be concerned that it might not trip when it’s actually supposed to? [/hijack]
No there’s certainly no pennies in the fusebox. We’ve blown fuses before, so the fusebox does do something at least. Why it didn’t short in this case, I don’t know. We’ve had an experienced electrician look over our house before (the neighborhood electrician is a close friend of the family), and he never noted any problems. Perhaps I’ll ask him more about our house and the houses in the neighborhood.