got a neon tester screwdriver? yes? then read this

[shaggy]

When I asked 'Where's breezer?' I knew he was on Christmas Island but I meant 'Where is he on the thread?' How could he start such a controversial thread about the safety of an piece of test equipment and just sit back and leave it? Clearly the neon screwdriver is an excellent device and I think this is another of his wind-ups, like when he goes off the deep-end when someone mentions pulling the service fuse.

 

[PaulAH]

the earths do not get connected to an RCD. only the phase and neutral. the RCD detects the imbalance of current between phase and neutral,

Thanks Andrew, that's why I said "or some kind of leakage detector". So have you any idea what they were trying to achieve, and what alleged change in regulations made the earths (or whatever you might call them) redundant?[/quote]

 

[andy]

Thanks Andrew, that's why I said "or some kind of leakage detector". So have you any idea what they were trying to achieve, and what alleged change in regulations made the earths (or whatever you might call them) redundant?

never herd of the 'bond all radiators' thing. but the point in bonding everything is to make everything at the same potential to prevent shock. hopefuly everything will be bonded properly so if there is a fault and current flows thru water pipes etc there will be enough flow to trip the RCD before any1 is able to get a belt

 

[Tony6]

Well the best thing about this site is the disscusion.Nothing like a good old ego trip.

The first thread i wrote was information given to me at college by a college lecture who is corgi and offtec reg
someone who you assume is experienced in his field.

I simply asked is this true .hoping someone could clarify it for me.

as the following thread was also explained as an example.

if this is b*ll*cks as ban all sheds wrote then please explain .

the more questions that are thrown in the mixing pot and anwsered the more you learn i thought thats what this site was all about .

but it seems to be a site dedicated to a few people who simply like to get off on being ego warheads ............


maybe what the lecture should of said was,if the neon was faulty you would be the live conductor to earth by touching it?

but again that might be more b%ll&cks......hopefully someone can answer this one?

 

[ban-all-sheds]

He's a plumber, not an electrician - at least that's what you told us...

When you touch the end of a neon tester to a live conductor, a tiny amount of current, limited by the resistor (and the neon) flows through you to earth.

If the nature of the tester does not change, and nor does the resistance of your body, the only way that more current can flow is if the potential of the live conductor increases.

Please explain how a fault connection between a live conductor and earth can cause the potential of the live conductor to rise with respect to earth?

 

[Tony6]

Please explain how a fault connection between a live conductor and earth can cause the potential of the live conductor to rise with respect to earth?
__________________

In a nutshell i cant, im not an electrican.im a mason by trade .

I decided to go back to school last year and learn plumbing .The advice given albeit b%ll%cks .was from the college lecture and again he is not an electrican but a plumber dealing with electrics daily {central heating engineer. }

if you dont know something and someone who is a professional in their field tells you then you tend to believe them or question it .

which was what i did at the start.?

 

[breezer]

have you ever wondered what happens when you connect your neon screwdriver to 230v try it and see.

my point is that by design yes they do have a current limiting resistor, but they will light at almost anything (try as i just said and see the difference) being able to lioght at almost anything is what makes them of no use, unlike a meter (even if its not calibrated) it still gives an indication of what voltage is there, not as neon screwdrivers do (just there is a voltage)

as i have also mentioned (and everyone really knows) use the right tool for the right job, you wouldnt want your doctor to listen to your heart through an upturned glass would you, so why use a neon tester.

merry Christams

 

[PaulAH]

If the nature of the tester does not change, and nor does the resistance of your body, the only way that more current can flow is if the potential of the live conductor increases.

Sums it up nicely (I=V/R)

Please explain how a fault connection between a live conductor and earth can cause the potential of the live conductor to rise with respect to earth?

Can't see how this might happen, unless the fault was a wierd one like shorting to an HT circuit somewhere. Which is why the claim has met with some doubt!

 

[TraineeSpark]

Oilman, was only trying to post a quote or two.

*Removed*

[Moderator: Lets keep the abuse to a minimum please]

 

[TraineeSpark]

*Removed*

[Moderator: Lets keep the abuse to a minimum please]

 

[TexMex]

TraineeSpark. It's Christmas! I'm only on here to pass the time, while I wait for the grand children to go to sleep. (Got their stockings ready to hang on the bedposts). What's your excuse?

Tis the season to be jolly! Lighten up it bit. Goodwill to All men and all that. You've not been at the sherbert already have you?

 

[Damocles]

Well my point was that the accident rate on electrical work is really pretty low. Get an electric shock and you stand a very good chance of coming away with nothing more than a determination not to do it again. I think there would be a lot more agreement about some things if there was a clear cut right and wrong answer. There is not always one. There are different ways to do the same thing which are acceptable within regulations, and different ways to do the same thing which while no longer acceptable for new work would not be so serious as to require instant replacement. Then there are regulations which say general sorts of things, and people argue about whether a certain practice is acceptable or not.

I think the trouble with neons is that they use your body as one of the test probes. As a general thing it is probably good to avoid using your body as test equipment, just in case. Also your body makes a pretty crap probe and a poor contact. So do not ever expect a neon to give a precise answer.

Apart from that they are cheap, have few parts to go wrong and do work. You only need one hand to operate it. Like any test equipment, you need to understand what the readings mean if you are to use them properly. They give some indication of whether a conductor is really live or only floating from the brigtness, but this is also affected by the quality of contact between you and ground.

 

[oilman]

Oilman, was only trying to post a quote or two, but as you seem to have taken exception to this please allow me to ask a question? Would your neon screwdriver indicate "complete **** **** if you stuck it up your a**e?" Cause that really is the best place for it.

Well, well. Traineespark, you are an apprentice then? (your statement). I had not levelled any personal abuse toward you, I had pointed out some facts which need to be researched, like what GS38 applies to, and to point out that writing a book is not necessary an indication of how good anyone is. Given that, if the author really said a neon screwdriver will indicate anything from 5V upwards he is NOT very good. You need to do some research on neon lamps and what voltage is needed to light them.

However, your attitude is one that the industry could well do without. Even if you aren't aware of it, it will be noticed by your future customers who will then label the industry as full of cowboys. If you can reason your way round technical discussion you would be ok even if you get things wrong just as the rest of us do from time to time. Had you just come back from the pub?

 

[oilman]

have you ever wondered what happens when you connect your neon screwdriver to 230v try it and see.

Um... the neon strikes and shows the voltage was at least 90V(peak) ie 180V pk-pk if ac (the rms value is not important as the peak voltage is what's causing the striking)

my point is that by design yes they do have a current limiting resistor, but they will light at almost anything

Well yes if "anything" is defined as being greater than a minimum required voltage

(try as i just said and see the difference)

Oh come on, give us a hint, the difference between what and what?

being able to lioght at almost anything is what makes them of no use, unlike a meter (even if its not calibrated) it still gives an indication of what voltage is there, not as neon screwdrivers do (just there is a voltage)

If your meter is not calibrated you have no business assuming what voltage is there, it might be totally wrong. The lead might be open circuit and indicate nothing. "Calibration" does not have to be to NPL standards, but it does have to be something, even if only the local mains voltage, or your car battery. Then allow for the errors. See earlier for neon limitations.

as i have also mentioned (and everyone really knows) use the right tool for the right job, you wouldnt want your doctor to listen to your heart through an upturned glass would you, so why use a neon tester.

There is nothing WRONG with a neon just as there is nothing wrong with a light on a lead FOR THE RIGHT APPLICATION. And doctors might well just feel a forehead to get a rough indication of the temperature of a patient before making furthur checks. I doubt they are fitted with calibrated fingers. They look at tongues with uncalibrated eyeballs, they tap on chests with uncalibrated fingers and listen with uncalibrated ears, the same uncalibrated ears which listen through the stethoscope. And how good are your ears?

merry Christams

Merry Christmas

 

[shaggy]

breezer said:

you wouldnt want your doctor to listen to your heart through an upturned glass would you,

If it was an emergency, and that was all he had, then the answer is yes.Have a read here
Breezer, if you were doing a job and your test meter failed, perhaps because the battery was down, wouldn't you be pleased you had a neon as a back-up? I bet you carry one like everyone else.