insulated wire giving shock

Question

I'm having some problems at my new girlfriend's house. There was a extension cord that was giving shock and I changed to another. This one wasn't giving shock, but when I test it with that screwdriver that lights up a light on electricity, it lights up when touching the plastic part of the wire. The outside I mean. And it is happening with all the extension cords of the house.

What I want to know is if it is normal to the outside part of the wire to conduct correct or if maybe there is a problem with the house electrical system.

English is not my primary language, sorry for any mistakes.

Edit: on the others extensions of the house the light is on although it is very dim

that is not normal or safe... sounds like a possible missing neutral somewhere — , Oct 13 '18 at 01:32
You should get an electrician to look at the house. I'm not sure what could be causing that, but it sounds dangerous. — Hearth, Oct 13 '18 at 01:32
Please show a picture of the cords and tester in question. Is the "screwdriver that lights up a light on electricity" a non-contact voltage tester? — K H, Oct 13 '18 at 01:33
https://www.dropbox.com/s/vb35cxv7npuq4xi/IMG_20181012_223645.jpg?dl=0 I think it is. — Vinícius, Oct 13 '18 at 01:41
need more info, where does the shock happen? this isn't a male-male cable, is it? is the shock in the middle, by the connection, or maybe at the end? — tuskiomi, Oct 13 '18 at 01:45
This is a female-male cable. The shock is on the male plug. Then I tested with that tester ( how is it called?) and it turned on like the picture. The I tested the other extensions on other outlets and I was not getting any shock when I touch, but there is a dim light. I thought that the cables was isolates so no light should be on on the tester. This is a pic from another extension. https://www.dropbox.com/s/hwvfv61bhe9d1wq/IMG_20181012_225139.jpg?dl=0 — Vinícius, Oct 13 '18 at 01:52
is "that screwdriver" metal or plastic, and does it have a battery?" — Jasen Слава Україні, Oct 13 '18 at 03:11
The part that touches the wire is metal, it connects to a resistor and the resistor connects to a light. The light connects to a metal plate that touches the finger. Like this: https://img.lojadomecanico.com.br/IMAGENS/19/189/76541/Chave-de-Teste-com-Ponta-Fenda-18-x-3-Po-tramontina-419001101.JPG?ims=500x500 — Vinícius, Oct 13 '18 at 03:24
Those Neon testers are pretty sensitive and should not be your only test instrument. — KalleMP, Oct 13 '18 at 06:39
New girlfriend = behave manly and try to fix everything. Sensible approach is think with your brain and not your trousers and get an electrician. — Andy aka, Oct 13 '18 at 11:07
I'm sorry, I do work wirh electrical installation on buildings, have a course on it (not graduation though) but came here asking because I never saw something like that. Of course I'm trying to fix everything, but I have never seen the male plug giving shock. (Neither the outside of the cable with any live tension). Is there any explanation on why the male plug was giving shock and lighting up the tester? The other wire lights a dim light and not give shock, but I thought that the insulation was to prevent that. — Vinícius, Oct 13 '18 at 12:11
What test do you suggest? I have a digital multimeter and general tools. — Vinícius, Oct 13 '18 at 12:20

score 1 · Accepted Answer · answered Oct 13 '18 at 14:21

If you get an electric shock when touching the plug of the extension lead then it is likely that the plug and/or the wiring inside is at fault. From the pictures you showed, I would suggest removing the old plug and replacing it with a good-quality new plug, also cutting back the wire to start in a new place.

A neon mains tester such as you showed in another picture works by you being a capacitor (this is normal, nothing to worry about). There is an explanation at How does the tester screwdriver work?

I notice that the extension cord is only two wires. A safer version would have two wires with another insulator over them, like this:

(Image from the CPC website)

However, what I recommend is to buy a new extension lead with a moulded-on plug and socket. This accomplishes two things: it will be safe, and it shows you care.

score 0 · Answer 2 · answered Oct 13 '18 at 13:42

If that “light-up” tester you are using is one to detect the PRESENCE of electricity without a physical connection to the wire then it is working correctly.

If that tester is one that requires a physical connection then there is an issue that has to be corrected - perhaps moisture on the surface could be the culprit...

insulated wire giving shock

2 Answers2