Neon / Mains Tester Screwdriver – Good or bad?

ThisIsWeird

I got into a slightly paranoid habit of carrying out one final check that a 'live' was truly dead before doing such work - I'd touch it. 

By that I mean I'd very quickly flick my finger across the released bare wire. Always curious whether it would actually work - I haven't managed to do it on an actual live wire yet... I'm hoping that the microsecond contact time would indicate if it was live, but not carry any actual risk?

I wonder?

Once 'flicked', I could tell myself with 100% certainty that I could go on to handle the wire with impunity.

(In theory, if the contact time aligned with the AC cycle being at zero volts, then it would be a rubbish test )

chrisw

ThisIsWeird said:

I got into a slightly paranoid habit of carrying out one final check that a 'live' was truly dead before doing such work - I'd touch it. 

By that I mean I'd very quickly flick my finger across the released bare wire. 

Touching the wire with a finger doesn't seem a very good idea, but I do often touch a released bare wire to the earth or neutral as a final final check before touching it.

Section62

ThisIsWeird said:

(In theory, if the contact time aligned with the AC cycle being at zero volts, then it would be a rubbish test )

It's also a rubbish test because when you do the 'flick' you might be insulated yourself and therefore not able to form part of a circuit (like a bird perching on the wires on an electricity pole or pylon).

But then when you touch the 'flicked' wire with one hand, and touch something earthed with the other hand, you better start hoping the circuit has RCD protection and it works perfectly when you need it to.

One of the golden rules of electrical work is to avoid touching stuff unless you have to - deliberately touching a conductor as a check it isn't live is definitely a bad idea.

ashe

I am a complete fanny when I do any electrical work and always try and avoid touching the wires but sometimes it feels unavoidable. 

If the unit is off at the consumer unit, what is the actual risk out of interest? Is it just that someone may have flicked it back on or can consumer units somehow not actually turn the power off?

I always turn the entire unit off rather than just that circuit as you never know what things are connected to - e.g we have some lights that spur off some plug sockets in the bed room. 

Section62

ashe said:

If the unit is off at the consumer unit, what is the actual risk out of interest? Is it just that someone may have flicked it back on or can consumer units somehow not actually turn the power off?

I always turn the entire unit off rather than just that circuit as you never know what things are connected to - e.g we have some lights that spur off some plug sockets in the bed room. 

The risk, as implied by the second part of your post, is turning off a circuit  which you think is the right one, but in reality the point is part of a different circuit.

In an environment where there are other people there is also a risk of the power being turned back on by someone else, which is why 'lockout' devices are available.

Turning the consumer unit off may be helpful if there is doubt about which circuit needs to be isolated, but that in itself can be a false sense of security as the "main switch" might not isolate everything, and in some cases there may be more than consumer unit.

This is why it is important to de-energise the circuit(s) you will be working on in a way which allows them to be positively tested for dead, rather than using a method which relies on chance.  (e.g. the method involving observing that a light 'bulb' has gone out could be that a plug-top fuse or lamp has failed by pure coincidence)

dil1976

grumbler said:

You can by a multimeter for a tenner at Screwfix, but personally I'd just plug a lamp in the socket, switch it ON, then switch the main swich (not the MCB) OFF in the CU and check that the lamp went off.
https://www.screwfix.com/p/lap-ac-dc-digital-multimeter-600v/75337

Absolutely terrible bit of advice, as the neutral may only be switched off if polarity is incorrect leaving the line at 230 volts leading to a fatality.

Ectophile

ThisIsWeird said:

I got into a slightly paranoid habit of carrying out one final check that a 'live' was truly dead before doing such work - I'd touch it. 

By that I mean I'd very quickly flick my finger across the released bare wire. Always curious whether it would actually work - I haven't managed to do it on an actual live wire yet... I'm hoping that the microsecond contact time would indicate if it was live, but not carry any actual risk?

I wonder?

Once 'flicked', I could tell myself with 100% certainty that I could go on to handle the wire with impunity.

(In theory, if the contact time aligned with the AC cycle being at zero volts, then it would be a rubbish test )

I would rather poke it with a neon screwdriver myself.  At least that puts a roughly 1M ohm resistor between you and the mains.

Risteard

Simonon77 said:

Risteard said:

paperclap said:

Didn’t know you could pick these up this cheap!

So, multimeter or the plug socket tester?

Is there a preferred?

A GS38 compliant approved voltage indicator.

You will likely also need a proving unit.

Or for someone who is going to do very occasional home work on the odd socket, a multimeter is fine

I'm afraid the HSE wouldn't agree with you.

Simonon77

Risteard said:

Simonon77 said:

Risteard said:

paperclap said:

Didn’t know you could pick these up this cheap!

So, multimeter or the plug socket tester?

Is there a preferred?

A GS38 compliant approved voltage indicator.

You will likely also need a proving unit.

Or for someone who is going to do very occasional home work on the odd socket, a multimeter is fine

I'm afraid the HSE wouldn't agree with you.

How many people doing DIY jobs at home really care about the HSE ? Common sense can work a lot better than slavishly following rules

Simonon77

Risteard said:

Simonon77 said:

Risteard said:

paperclap said:

Didn’t know you could pick these up this cheap!

So, multimeter or the plug socket tester?

Is there a preferred?

A GS38 compliant approved voltage indicator.

You will likely also need a proving unit.

Or for someone who is going to do very occasional home work on the odd socket, a multimeter is fine

I'm afraid the HSE wouldn't agree with you.

Of course I realise you have a vested interest in discouraging anyone from going near anything electrical ( which you do on most posts about electrical problems ) which is fine for people who have no idea. For anyone reasonably competent and sensible they can replace sockets etc.. without needing hundreds of pounds of professional equipment or having to fill in risk analysis forms and checking the HSE rules...