Neon Screwdrivers....

BestGear · Sep 14, 2013

Hi Guys

I was using a neon screwdriver in friends house, to confirm the power had been removed at a ceiling lighting junction box.

The junction box was to be replaced - a straight swap as something in the attic had fallen on it and cracked the casing.

I brought in the feed live, neutral and earth first, noticed that if I touched earth or neutral with the neon screwdriver, the neon lit up!

Obviously I was not expecting that... so assume the earth impedance is kind of high, and as for the neutral - gob smacked that it was not at earth potential..or very close to...

I made good the repair and left him to get it checked by a pro...

What do you think?

Is this common?

I did not use a meter to measure impedance or even floating voltage on the earth or neutral, which I could have, but when it was enough to light a neon (which is min 90v from memory) I walked away...

I appreciate that the current to light the neon is tiny, but surely that ain't right!?!?!?!

Thanks

David

Darkwood · Sep 14, 2013

All you need to know is as students the colleges ban neon drivers they pick up induction are misleading and if they fail you may think a cable is safe when in fact its live..... the only reason they are not banned in the UK they have an alternative function of turning screws.

telectrix · Sep 14, 2013

and cleaning out the nozzle on your tube of caulk.

ian.settle1 · Sep 14, 2013

Should be banned by law there bloody dangerous

Johnuk · Sep 14, 2013

I only use the screwdriver end

Tiny Spark · Sep 14, 2013

I used to have one of the blue plastic ones which used to come in handy for quick indication testing.
But I certainly would not trust them or use them for proving dead.

A quality multi meter is where its at.

BestGear · Sep 14, 2013

I fully understand what you are saying Guys...

BUT - what do you think re it illuminating on E and N?

Tiny Spark · Sep 14, 2013

They will pick up on the most tiny currents.
You may of had a small amount of earth leakage or something.

BestGear · Sep 14, 2013

Tiny Spark said:
They will pick up on the most tiny currents.
You may of had a small amount of earth leakage or something.

Should my mate live with it or worry?

I guess the answer is to measure it and see how bad it is!

I will check to see if the lights are on a RCD... there is a split load CU.. and only half is on a RCD... so the lights may not be.

David

Tiny Spark · Sep 14, 2013

To be honest its not something I would worry about.
As I said above, they are not to be trusted and should not have any faith put into them.
If you want to test the circuit or the installation in general you should use the proper gear or get someone to do it for you.

telectrix · Sep 14, 2013

........ using a neon screwdrver to test for dead............ dipstick. rely on one of them you could end up dead.

Guest111 · Sep 14, 2013

I once had a neon light up on a 6mm t&e that was cut off at both ends,I know it was dead because I isolated it,they are not safe or reliable,one of the lads had one and he just used it as a screwdriver anyway the apprentice dropped it in the sink dried it off and said nothing.The spark went to check a loose connector on a ceiling rose and the power was still on,bang and he ended up on the floor,Yes it should have been isolated,yes the apprentice should have said he'd dropped it in the sink,but ultimately if it had been an ordinary driver he wouldn't have got the belt.

Wiresandthings · Sep 14, 2013

http://youtu.be/AGXQNLq19FQ

This should give you an insight as to why these drivers are bad, and if you watch to the end you'll see how good a decent insulated driver is at protecting its user

The bloke in the video is a nutter but he does some pretty cool stuff on his other vids

BestGear · Sep 14, 2013

Ok, so I think we have ascertained you lot don't like neon screwdrivers...

So what is the likely cause of the earth and neutral being above (or below!) 0v potential to light it up?

Regardless of what the test tool was, it showed that there was potential between earth (me) and something that should have been at the same level.

Explain it to me in terms of what you have found in the field (ie real life, not hypothetical) causing it... dont treat me like a dipstick... and I am happy for any detailed electronic explanation...

David

Marvo · Sep 14, 2013

First thing to do is to test the circuit using a suitable instrument.

Dizzy_Maskell · Sep 14, 2013

Abolish them let DIY ppl think they know what they are doing death traps screwdrivers dangerous too

Silly Sausage · Sep 14, 2013

These neon screwdrivers can't be that bad.
The NICEIC sell them.

Kompakt VDE Slimline Pouch Set 16pc WER003484

ferg · Sep 14, 2013

Archy Styrigg said:
These neon screwdrivers can't be that bad.
The NICEIC sell them.

Kompakt VDE Slimline Pouch Set 16pc WER003484

Remind me again how that is a glowing reference

shanky887614 · Sep 14, 2013

Dizzy_Maskell said:
Abolish them let DIY ppl think they know what they are doing death traps screwdrivers dangerous too

A cheap multimeter costs less than £20 so why do people trust these neons?

Probably because the coffee stirers are a freebe in a pack of suposedly electrical screwdrivers

BestGear · Sep 15, 2013

Marvo said:
First thing to do is to test the circuit using a suitable instrument.

Other than the obvious multimeter, what instrument are you thinking about?

Given the high impedance a multimeter presents, I would not be surprised if it shows a potential on E and N just as the neon did....

That still does not explain what or where the issue is likely to be....

telectrix · Sep 15, 2013

this is what you should be using...... or similar.:

[ElectriciansForums.net] Neon Screwdrivers....

Sintra · Sep 15, 2013

BestGear said:
Other than the obvious multimeter, what instrument are you thinking about?

Given the high impedance a multimeter presents, I would not be surprised if it shows a potential on E and N just as the neon did....

That still does not explain what or where the issue is likely to be....

Induced voltage use a decent analogue meter and it will probably show zero. Why you want to put your live at risk using a neon is beyond me.

Sintra · Sep 15, 2013

5c077 said:
Think it's all funny with all your remarks towards the screw driver and with the clever replays wouldn't judge any1 by trade as still learning the trade myself but I don't see any safe means of isolation in your descriptions such as lock off your breakers and using a proving unit as a known source when you are insuring the a indicator instrument so wots any different using a screw driver to not using a multimeter cuz your readings could be false any way with out checking at known sorce and keeping logs of your reading to ensure that range of value of your instrument is as close as I feel that work ain't being carried out correctly because you should have access to any certificate reports and things to current reg is to be labled or marked indicated of its isolation so wot you need a £1 neon screw driver I don't know wot you pay for is wot you get sounds like some had it bad if there on the floor made me chuckle employ someone with decant tool and expire nice cuz I can work on a live circuit alday and still not get a belt that comes down to experience and 100% good quality and well maintained tools and cleaned from any excess of water in one post as I chuckle to myself

Well you must be as crazy as the people that use neon screwdrivers for voltage testing.

ferg · Sep 15, 2013

I gave up trying to read that.
No punctuation and spelling a 4 year old would be ashamed of.

ferg · Sep 15, 2013

As per my last post.

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Guest111

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Dizzy_Maskell

Silly Sausage

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