I am not sure that my question is suitable for here but I can't find an answer anywhere.

I live in Europe and I just moved to a new apartment. In my bedroom I have 1 electrical socket. I connected an extension cord to this socket so I will be able to connect my PC to it, screens, phone charge and a laptop charger.

Now, when I accidentally touch the USB connector of my charger or a usb port on my PC or any metal thing that is connected to the socket i get a static electrical shock.

I think that this is because of the grounding but I really dont know. Is changing the extension cable could help?

  • 1
    diy.stackexchange.com/a/104542/46271. Related
    – Kris
    Jun 1, 2019 at 21:32
  • @Kris Thanks. I understand the danger with it. So, do you think that maybe changing the extension cable will help?
    – HakoStan
    Jun 1, 2019 at 22:13
  • 1
    Is the shock something that keeps happening, or is it a single zap that does not recur if you keep poking the metal bits? Jun 1, 2019 at 23:41
  • 1
    How do you know it is static? Jun 2, 2019 at 1:52
  • 2
    Wait wait wait. If you touch it twice without moving your body in between, do you get zapped twice? THAT'S NOT STATIC ELECTRICITY, THAT IS MAINS TRYING TO KILL YOU. Jun 2, 2019 at 14:08

2 Answers 2


What's happening is you are being bit by mains electricity. And this has happened (so far!!!!) under conditions where mains was not able to flow enough current to murder you.

Those conditions are subtle and quick to change. If there were higher humidity, if a neighbor turned on their dryer, any number of other things... that same shock could be fatal or maiming.

So I would stop pulling the dragon's tail if I were you!

Put it this way. "I need to use my PC, though" is less than "I need to not live in a wheelchair for the rest of my life". continuing using this as-is, is simply not an option.

There are two areas this can occur in. First, that power service may have a problem. That's easy to suspect in the old Eastern Bloc particularly, but it's not necessarily true. Contact your landlord and have him have it checked out.

Second, it can be your own equipment, especially if the equipment requires a ground connection and the socket is not grounded. Grounding is a safety shield, which is designed to catch wayward current. The problem is when equipment ground is not connected back to a competent ground back at the service panel and its equipotential bonding, it simply electrifies the grounded chassis of the equipment.

Worse, if several pieces of equipment are all plugged into a grounded power strip, and that isn't grounded to building, then you have what I call an "island of grounds" - so a ground fault on one piece of equipment will share the ground fault with all devices, electrifying all their chassis.

The usual culprit in PC equipment is cheap junk bought mail order, or smuggled in and sold at cheapie shops or flea markets ... in those cases, you're the importer - guess who is responsible for the item complying with CE safety standards! (the importer).

The first workaround is get a plug-in RCD. This will detect fault currents sufficient to kill you (like the one you've been feeling) and trip the power to your equipment to prevent that from happening. Consider this mandatory to even continue using the equipment. This will be a good time to not play your hardcore Diablo character :)

I would love to give you a diagnostic tree for chasing down this problem, however it's absolutely unacceptable to be touching the equipment to feel for a shock as a diagnostic method. Change conditions slightly and it becomes lethal - and the whole point of troubleshooting is to change conditions!

Try getting a €5 "non-contact voltage tester" and see if that will detect on the places you had been getting zapped.

Even so, be cautious of 2 pieces of equipment, one with a ground fault to neutral, the other with a ground fault to hot. Touching both at once can kill you, and the RCD wouldn't detect that. If you have reversible plugs, that situation could develop simply during unplugging and replugging things. The non-contact voltage tester will only detect ground faults to hot, so you might try flipping it and checking again.

If you have equipment with ground faults, get it fixed. If it's a PC, only the power supply needs to be replaced.

  • Hey, thank you very much for your explained and well written answer. You can definitely consider this answer not only correct but life saving as well. I will do as you suggested
    – HakoStan
    Jun 2, 2019 at 18:08

I really can't speak for Europe but in general, most of the time for those who are getting shocked by the electrical system, it is a polarity issue. Meaning the neutral and the line side conductors were crossed over when terminated. If it's not that, then the grounding or earthing conductor is open for some reason.

Changing out the extension cord may help if the one you are using is not a three wire cord (hot, neutral, ground). If it's only a two wire that may be where the earthing conductor is open.

Sidebar: a well grounded system will also prevent static shock since all electrical potential will carry to ground by conductor and not through your body.

Good luck

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