Almost electrocuted!!!

Discussion in 'Lawn Mowing' started by Envy Lawn Service, Nov 23, 2004.

  1. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Messages: 11,087

    Weird story, and please feel free to explain how the heck this happened to me exactly.

    OK, it's a rainy day today, so I figure it is a good time to get in the shop and do some service work on the equipment. So I get to the ZTR and get to the point where I decide I'm gonna go ahead and check to see how the plugs are looking in the Kawasaki so far.

    But, on this unit the battery is outboard, by the engine. It has to be removed in order to access the plug on the left side. Another reason it was good to go ahead and have a look at the plugs on a rainy day.

    Anyways, I proceed to remove the battery and the cables on this particular unit happen to have been fastened with lock nuts on the bolts, which is a pain. Anyways, I start taking them loose and the tool slips, arcing the positive terminal to the valve cover on the Kawasaki. Sparks fly like a mother!!! I'm talking welding/plasma cutting level sparks!!! Molten metal splatters, landing on and burning my hands. This happens not once, but twice before I can get away from it.

    Now the strange parts to me are.... I was not wearing gloves and I was standing on a wet floor, but I did not get shocked. Second, I was serious about the molten metal flying. It burnt things black, melting the tool, the bolt and two spots on the valve cover. The third thing is that the battery holder/guard is also metal and bolted right to the frame. The other tool which was still on the nut fell down on the holder after the fact, effectively arcing the same way. But nothing happened there. No arc, no spark, no nothing.

    I understand the basic concept and I realize I made a boo boo. But I do not understand what caused such a violent arc between the battery, tool and valve cover on the engine because it does not arc any other way.

    Anyways, I'm waiting right now to find out if the valve cover was cut deeply enough to need replacing and I will be going in the morning to get the proper battery hardware to reconnect the battery so I can see if I fried any of the electrical stuff. BUMMER! Me and electricity do not get along I guess....
  2. tiedeman

    tiedeman LawnSite Fanatic
    from earth
    Messages: 8,745

    I think that your boots saved you from getting shocked. Now if you had a nail on the bottom of your boots (saw it in a CSI) then you would be fried
  3. specialtylc

    specialtylc LawnSite Bronze Member
    Messages: 1,656

    You did a direct short from positive cable to ground. You need to remember that its only 12 volt but its about 300 amps. Its those amps that cause the damage.
  4. AllStarLawnCare

    AllStarLawnCare LawnSite Member
    Messages: 23

    You just learned the hard way why you disconnect the negative terminal first!

    The negative terminal is usually connected to the chassis, and then the positive is brought wherever the juice is needed. In your case, the negative terminal is connected to the chassis which ends up being connected to the valve cover and your wrench successfully brought the positive and negative together.

    The reason you didn't get electrocuted is because you weren't part of the circuit. Stick a u shaped paperclip in an outlet and you'll get burned but not electrocuted because your hand is not near as good a conductor as that paperclip. Now if you'd had one hand on your valve cover and the other on the tool working the positive terminal, you might have been typing this thread a little slower.
  5. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Messages: 11,087

    No, actually I disconnected the battery in the proper manner, by disconnecting the negative first. I guess that is why it doesn't arc off the battery holder/guard. I do not even pretend to understand electricity, but I know that much. I just don't get why it arced so hard off the valve cover.

    Now your description of the 'curcuit' must be part of how I survived my famous "220 and a metal hanger" incident.
  6. Nick911Racing

    Nick911Racing LawnSite Member
    Messages: 13

    The reason you didnt get electrocuted even though you were in water is because the electricity took the path of least resistance which was to through the wrench on the positive directly to the negative side since the block is connected to the negative terminal. On house wiring the reason you can get electrocuted is because the physical ground is actually connected to the circuit in your circuit box. Basically the hot side of the electric to a house acts like the positive and the physical ground and neutral acts like the negative, so touching the hot side of an outlet and the ground makes you the only path for the electricity. The reason I say "acts like positive/negative" is alternating current (house current) has different characteristics than direct current (12v car system). Anyway, the physical ground has nothing to do with a automotive 12v system, so you cant get electroucuted even if you are standing in a puddle of water (true 99% of the time). I also have never heard of anyone being electrocuted by an automotive electrical system (ignition system excluded).

    Specialtylc was correct in his statement because voltage does not kill a person, amperage does. 1 amp is more than enough to stop your heart.

    Sorry if this response seems long winded or boring, but electricity is one of my interests.

  7. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Messages: 11,087

    Ok, so the 300 amps is what did the damage then huh?

    All I know is it sure surprised the crap out of me when it happened!
  8. Nick911Racing

    Nick911Racing LawnSite Member
    Messages: 13

    For the most part yeah. If you look at a welder, to increase penetration and amount of metal melted you turn up the amperage. Same theory.

  9. Mo Green

    Mo Green LawnSite Bronze Member
    Messages: 1,487

    I had a friend that went to the junk yard to find a used starter for his camaro. Well, he finds one and proceeds to crawl under the car to retrieve it. As he is taking the bolt loose from the solenoid, he gets the shock of his life. I mean a good one. Caused his whole body to shake. He crawled out in a bit of a daze and said "what the hell was that?" After a check under the hood, we found that the battery was still in the car and still connected. Tuff way to learn a lesson I guess, for him anyway.

    And by the way, .50 amps can kill you.
  10. Eric 1

    Eric 1 LawnSite Bronze Member
    Messages: 1,220

    And that begs the question, what was the story?

    I cant understand how it arced if the negative cable was off. I guess the mower became grounded and that shorted it out, but i would think the tires would insulate it? You got me.

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