1. ## Water And Electricity

I have heard some people say putting water on places where electric current is runnig through wont shock you, then like many people say it will shock you, so I am on the hunt to find out the real answer, I know it probably sounds stupid asking "If you spray water on electric will it shock you?" So whats your thery about it, I dont know but I have heard many things on each side of this subject.

2. Now I could be wrong here, but judging from the amount of times that we've been told to "watch out" for the overhead power lines when pushing water, I'd have to say that yes there is potential. It's my understanding that if you are running a straight stream, and you hit a line that the electricity can flow down through the water. Don't take this as gospel though, as I'm not entirely sure. I'm sure one of the Crusty's can give you a better, more assured answer.

All I know is that when I'm on the nozzle, I look up before spraying anything up.

3. By "electrical" you have to differentiate between like a duplex outlet and a switch gear.

Flowing water into relatively low voltage applications is probably unavoidable. If everything is working properly, you won't get zapped. However, heavy duty stuff like switch gears, multi-phase panels and the like should not have water sprayed into them. There is a risk that the current will be able to flow up the stream, but this is not the chief risk. The reaction of water on a live high voltage electrical application will be violent. You run the risk of increasing the hazard due to damage to the equipment and by possibly charging the runoff water. In addition, arcs can jump a gap. The width of this gap is increased by conductors entering the gap. Water is a conductor.

The main danger from spraying water on the overhead lines is knocking them down or damaging them with the stream.

4. Backdraft,

Using a solid bore or a straight stream can cause a problem, depending on distance and type of pipe used. I've had it happen once a long time ago when we were using Rockwood nozzels (still love those things). Now on dwelling fires if the truck doesn't get the electrical turned off right away, you can actually feel the electrical current (lower voltage) through your body while crawling through the water soaked dwelling. Feels like a tingling sensation and sometimes can give you a decent little shock. George is right about not playing around with the high voltage electrical, thats why they have class C distinguishers. I wouldn't consider using the water unless I had no choice, which would be quite a rarity if ever and if you did, stay out of all running water from the stream, especially with any downed wires. Wait for the electrical company if you can't use a Class C extinguisher on it.

5. I agree with the previous posts, it's not as bad as everyone says but it is still bad. I have seen at a big worker where elevated streams were shooting over a powerline and the water mist was between the 2 powerlines. Like George said, the water mist acted like a conductor and the lines shorted. Looked like lighting struck, it looked awesome but made a bunch of guys fill their diapers. The stream was moved after that.

______________________
Lt.Jason Knecht
Altoona Fire Rescue
Altoona, WI

6. What brought the question up is on the hotshots page a Department had a fire at one of those electric substations and it got me curious and some others I talked to about it curious.

7. I don't know if this is the answer you are looking for - but here is my understanding of it:

De-ionized water will not conduct electricity - regardless of potential (voltage).

Normal water - if you want to call it that - is ionized and therefore will conduct electricity - regardless of potential (voltage).

8. Mesman you are correct, Pure water does not conduct electricity. It is the impuritites in the water that conducts.
We also have a sprinkler system (deluge) system around all of our transformers here at the power plant where I work. We have already had 2 of these transformers fail (catch fire) that look to be the same size as the ones the article mentioned. One transformer burned for 3 days, the other burned for 1/2 day.

9. Just got back from a two day program conducted by National Grid that covered electrical and nat gas fires. They did a demo with both 2 1/2' and 1 1/2" lines that shot a stream from straight and fog nozzels through a charged grid. On straight steam from both lines, the amperage at the nozzel was 60+ amps (it only takes .5 to kill you.) With the TFT set at 15 degree fog the was .01 amps at the nozzel on both the 2.5 an 1.5 lines. The instructors said that in a fog pattern there is air space between the molecules of water in the stream and hence it becomes a poor conductor of electricity. In the straight stream application the molecules of water are in contact and it is an excellent conductor.

Their point was to treat overhead lines as an exposure if they are in immediate proximety to a fire.If they are cooled and stay where they belong (up in the air)there is no problem. If they melt and fall to the ground where your people are operating now you have an additional hazard to deal with. Their reccomendation was a 10-15 degree fog pattern with the wind at your back as that will give you greater reach and allow you to stay back away from any potential hazard.

Also in the case of transformer fires on poles or in substations just protect the exposures and wait for the utility rep to de-energize things because the equipment is already junk. It was a very informative two days. I would strongly urge anyone who has an opportunty to attend any similar course to take advantage because it was two days well spent.

Just got back from a two day program conducted by National Grid that covered electrical and nat gas fires. They did a demo with both 2 1/2' and 1 1/2" lines that shot a stream from straight and fog nozzels through a charged grid. On straight steam from both lines, the amperage at the nozzel was 60+ amps (it only takes .5 to kill you.) With the TFT set at 15 degree fog the was .01 amps at the nozzel on both the 2.5 an 1.5 lines. The instructors said that in a fog pattern there is air space between the molecules of water in the stream and hence it becomes a poor conductor of electricity. In the straight stream application the molecules of water are in contact and it is an excellent conductor.

Their point was to treat overhead lines as an exposure if they are in immediate proximety to a fire.If they are cooled and stay where they belong (up in the air)there is no problem. If they melt and fall to the ground where your people are operating now you have an additional hazard to deal with. Their reccomendation was a 10-15 degree fog pattern with the wind at your back as that will give you greater reach and allow you to stay back away from any potential hazard.

Also in the case of transformer fires on poles or in substations just protect the exposures and wait for the utility rep to de-energize things because the equipment is already junk. It was a very informative two days. I would strongly urge anyone who has an opportunty to attend any similar course to take advantage because it was two days well spent.
Does this mean this is going to turn into a "fog vs. straight stream" thread?

11. I appreciate what everybody else has said here, but I myself am not a numbers or a science kind of guy. I too had a class in the study of electricity and what it can do to me in an emergency situation. The guy teaching the class told us it came down to this.
Do you feel comfortable enough to take a chance to shoot a fog pattern through a potential electrical field? And when do you know the electricity is starting to travel through the water (as in relation to the type of pattern you are using? Narrow fog, wide fog, or whatever) When in doubt, wait it out. Believe me, it is no fun, I have myself cut through a 220 line with a chainsaw while ventilating on a roof. I won't make that mistake again. Don't take chances with electricity. If you aren't sure, wait.

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