I get a shock when touching water pipe

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Discussion Overview

The discussion revolves around the issue of experiencing electric shocks when touching a water tap in an apartment. Participants explore potential causes, including electrical faults and grounding issues, and share their testing methods and findings. The conversation includes both technical reasoning and personal experiences related to electrical safety.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • The original poster, an Electrical Technician, describes measuring 120 V between the water pipe and hot wires after turning off all breakers, suggesting a potential electrical fault.
  • Another participant suggests that a bad Earth connection might be causing the shocks, proposing that a floating Earth wire could be picking up voltage and affecting exposed metal surfaces.
  • One participant emphasizes the danger of the situation and recommends consulting a qualified electrician for a proper diagnosis.
  • Another participant questions the grounding of the breaker box and the water tap, noting the potential for leakage and the role of Ground Fault Interrupters in the situation.
  • The original poster later indicates that the issue was resolved by changing the plug position of an old refrigerator, which was identified as the source of the problem.

Areas of Agreement / Disagreement

Participants express various hypotheses regarding the cause of the electric shocks, with no consensus reached on the definitive source of the problem. While some suggest grounding issues, others point to specific appliances as potential culprits.

Contextual Notes

Participants discuss the implications of electrical safety and the importance of proper grounding, but there are unresolved questions about the specific electrical configurations in the apartment and the effectiveness of safety devices like Ground Fault Interrupters.

adisabeba
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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
 
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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.
 
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.
 
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
 
adisabeba said:
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
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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