Testing

Thread Starter

mmkawa

Joined Nov 11, 2014
5
Today while i was checking my outlet(3 pin with live, neutral and ground), with a neon contact tester (on the live wire point/hole) and i got a shock(the tester should be plugged directly in the socket and user touches the metal part so the light glows), i don't know the reason, I tried it again it was the same, I used the same tester on other sockets and only light glows as usual but don't get shock, initially i thought its because of the ground wire which might got cut in between or something like that. But why does a live wire require a ground and where does grounding come into this, cause i am directly testing on the live wire?
I also tested with my electric appliances and there was no shock on touching the metal part. Its not the fault of tester, tested with other neon tester same result.
 

Brownout

Joined Jan 10, 2012
2,390
It could be that your live and neutral wires are switched. Using an AC voltmeter, measure from both live and neutral to ground. You should see the usual voltage from the live to ground, but not from neutral. If you're seeing voltage between neutral and ground and not live to ground, then your outlet is cross-wired.

I just today performed this experiment in the US.
 

Thread Starter

mmkawa

Joined Nov 11, 2014
5
It could be that your live and neutral wires are switched. Using an AC voltmeter, measure from both live and neutral to ground. You should see the usual voltage from the live to ground, but not from neutral. If you're seeing voltage between neutral and ground and not live to ground, then your outlet is cross-wired.

I just today performed this experiment in the US.
I will check that. But why I got a shock at the top of the tester? And tester was glowing, indicating the presence of current.
 

ErnieM

Joined Apr 24, 2011
8,377
Today while i was checking my outlet(3 pin with live, neutral and ground), with a neon contact tester (on the live wire point/hole) and i got a shock(the tester should be plugged directly in the socket and user touches the metal part so the light glows), i don't know the reason, I tried it again it was the same, I used the same tester on other sockets and only light glows as usual but don't get shock, initially i thought its because of the ground wire which might got cut in between or something like that. But why does a live wire require a ground and where does grounding come into this, cause i am directly testing on the live wire?
I also tested with my electric appliances and there was no shock on touching the metal part. Its not the fault of tester, tested with other neon tester same result.
If you are required to make your body part of the circuit to test an unknown outlet then please please please throw this thing away as it is potentially dangerous (no pun intended).
 

MaxHeadRoom

Joined Jul 18, 2013
28,686
Just about every electrician in the UK (240v) had one of these screwdrivers, they had a metal pocket clip at the top, the top had to be held when testing in order to use body leakage to ground, otherwise the Neon did not light.
I believe they are still available.
Max.
 

Thread Starter

mmkawa

Joined Nov 11, 2014
5
Just about every electrician in the UK (240v) had one of these screwdrivers, they had a metal pocket clip at the top, the top had to be held when testing in order to use body leakage to ground, otherwise the Neon did not light.
I believe they are still available.
Max.
So is it normal to get a shock on the top.?
 

ISB123

Joined May 21, 2014
1,236
It's not normal.Screwdriver tester are banned in some countries because if internal resistor and lamp fail and short circuit you are basically poking your finger in 220 Volts.
 

ian field

Joined Oct 27, 2012
6,536
Today while i was checking my outlet(3 pin with live, neutral and ground), with a neon contact tester (on the live wire point/hole) and i got a shock(the tester should be plugged directly in the socket and user touches the metal part so the light glows), i don't know the reason, I tried it again it was the same, I used the same tester on other sockets and only light glows as usual but don't get shock, initially i thought its because of the ground wire which might got cut in between or something like that. But why does a live wire require a ground and where does grounding come into this, cause i am directly testing on the live wire?
I also tested with my electric appliances and there was no shock on touching the metal part. Its not the fault of tester, tested with other neon tester same result.
Where you also touching something earthed - such as leaning against a radiator?

The tester I'm thinking of resembles a screwdriver, but has a hollow clear plastic handle, inside that is a high value resistor, a neon bulb and a spring to keep all the contacts pushed together.

They are designed to light with very low current pretty much using the capacitance of the users body as a load to the AC current.

The resistor should be high enough to limit current to a safe value in any situation.

The only things I can think of is a 110V tester on US house wiring that also has 220V outlets - or maybe the tester got wet somehow since the previous socket.
 
Top