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I get a shock when touching water pipe

  1. Nov 14, 2015 #1
    I am living in an apartment and suddenly we started to get an electric shock, at random, when touching a water tap. Since I am an Electrical Technician, I started

    my research on the origin of the problem, and after carrying out a series of tests I found out 'at the end' that turning off all the breakers (in the breaker box) and measuring the voltage between each hot wire and the metal box surface I got a full 120 V reading! The other tests I made were the following:

    1- I turned off all the breakers and then turned each back on, and then off, sequentially and measuring the voltage at the corresponding outlet. In all

    the cases I got a full 120V between the water pipe and the hot wire at the outlet. With this test I wanted to verify any leaking voltage of each breaker line.

    2- When testing the heater line (turning its breaker on), I found out that there was a 90 V reading between the hot wire and each of the two ends of the

    water heater resistance; of course, after I set apart the cables.

    So, the only clue I have is the breaker box-to-hot-wires voltage, and I wonder where and how the water line and the electrical metallic conduits shake hands. Any help?
    Thanks

    I was not really sure whether to add comments to my previous post regarding the problem I reported, since it was closed with not right to reply and suggesting the get an electrical technician. In such cases, I would suggest the Administrator of this site to leave the door open, so the poster could reply whether or not he has solved the problem. In my case, I did solve the problem by myself and I am an Electrical Technician.... Anyway, just for helping the audience with similar issues, "the problem was caused by my old refrigerator(1) and it was solved by swapping the electric plug position: the plug-outlet hot and neutral position must coincide." The electrical shock existed because the fridge's inlet water valve is connected to a copper tube and this to an external water filter. So, having a faulty fridge electrical issue, it explains the electric shock. I was really worried about the high life-threatening risk I was on, but it is luckily over.

    Regards.


    1- Whirlpool 8ED25DQXXN00
     
    Last edited by a moderator: Dec 5, 2015
  2. jcsd
  3. Nov 14, 2015 #2

    CWatters

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    Sounds like a bad earth somewhere. My guess is that the case of the heater has an earth wire connected to it but the other end of that earth wire or the earth for the whole place is bad. You might be seeing capacitive coupling between hot and this floating earth wire. In effect the disconnected earth wire is acting like an aerial and is picking up 80-120v and making it appears on exposed metal that is meant to be earthed.
     
  4. Nov 14, 2015 #3

    CWatters

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    PS This is quite a dangerous situation. You should get a qualified electrician to look at it. Have him show you the problem if you want to learn.
     
  5. Nov 14, 2015 #4
    So, do you have 240 coming into your house ? Here in the US we get 240 3 phase which appears as 120 if you look at either of the hot sides versus neutral (ground). Anyway, I assume your breaker box is grounded and so is the water tap unless the pipe is plastic. So it is strange that you would get shocked and potentially dangerous. Also, do you have Ground Fault Interrupters? Well , they ain't workin! Like you said, it could be leakage which a high impedance meter would read as full scale. Interesting problem. If you never respond again, I will know what happened... :H
     
  6. Nov 15, 2015 #5

    NascentOxygen

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    In cases like this you must employ a qualified electrician to diagnose and fix the fault, and you should do so immediately.

    Thread closed.
     
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