I have been using these for 50 years without any issue. The are 2 rules : 1. If the screwdriver lights up the contact point is live so take proper precautions. 2. If the screwdriver does not light up, do NOT assume the contact is dead.
Rule 3: Don't bet your life on a cheap 0,25W Resistor if you can help it. The old ones had far beefier ones and were made better but still. Now there are options which are just as simple to use without making yourself part of the circuit.
As a younger man I've tolerated many 220v electrical shocks (up to 20KV when working with CRTs) Accidents happen. As an older man with a a heart condition, I treat every wire as if it was live (unless I'm actually in unobstructed sight of both ends). The latter has, again been a life-saver. Never touch the wires, keep one hand away and stand on rubber mats.
You hear people saying they're dangerous and/or unreliable all the time, but are there actually any reports of anyone ever heing harmed by one of these? I've been using them all my life and have no intention of stopping. They are incredibly useful and I would trust one of these over a contactless volt tester any day.
Ive heard stories of people getting shocks, but it would be very hard to get data as it’s generally rare a shock like this would require a hospital visit. I personally think anything using you as part of the circuit is a terrible design, but everyone is entitled to an opinion. Thanks for watching!
Its more the problem of cheap parts, the 1/4watt resistors and is not rated for these voltages, it can fail open or short-circuit for instance. Poking a 400volt connection is probably also not a good idea. Etc there are tomanny possible failure modes. If you know what you're doing it's most likely fine but for the home gamer it's not something to rely on. I'd say because when using it you are part of the circuit now thankfully almost every installation here is rcd protected. As a funny side not my last step before grabbing a conductor is using the back of my hand as a last live check😅
@@TheDiligentDIYer1759 er, you are always part of a circuit because you absolutely always have a path to ground! Everything is a conductor, it's only the absolute level of impedance that varries.... lol ;-)
And you want to short yourself to 230 volts with no control. Good luck I saw a fellow Apprentice receive a horrendous electrical shock using something identical to this Don't
Back in the Eighties when I was training as a Theatre Technician, one of our lecturers had got a shock through a 400 volt neon tester. It SAVED HIS LIFE. While handling a lantern that was running on one phase, it shorted onto the motorised truck that it was mounted on. The truck was on another phase. The tester melted, and every hair on his body burnt off, but he lived. Because of that tester.
One of these may have saved my life. My son had a non working 13A socket in his house. I checked it with a multimeter and it showed as dead. I used one of these screwdrivers and it illuminated showing it was live. On further investigation I found the earth and neutral were both disconnected somewhere leaving only the line connected.
Below some voltage the light won't glow. You touch the wire and you get shocked ! 😀. At an isolated transformer it won't glow at any voltage ! You touch both wire and you get shocked ! 😀
I use a wire finder, as it detects electricity as well and reacts to small voltage and you don't need a closed circuit. In combination with a multi meter you then can find issues with a wire.
non-contact indicators often give false positives. they just glow, especially if there are a lot of wires and they are close, and you cannot know which wire is hot and which is disconnected. Non-contact indicators use a battery, and it often runs out, and even in certified indicators the sensitivity drops; this has happened to me often. Sorry, but the indicator screwdriver is a reliable, life-tested device. and the most reliable thing is a dial multimeter.
I have been using my device for more than 50 years. It has never failed, never broken anywhere, never had any foreign matter intrude into it and has always worked. Yes it can be hard to see the neon at times but it has always shown me when a wire or contact is live to mains voltage. Your fears may be sound scientifically but the chance of it happening is extremely slim. Using the bared-ended metal spikes of multimeter probes is far more awkward and way more dangerous.
Below some voltage the light won't glow. You touch the wire and you get shocked ! 😀. At an isslated transformer it won't glow at any voltage ! You touch both wire and you get shocked ! 😀
@@kenzo4Ever well if you are dealing with a voltage that won't light it up then the shock won't do much either. It's not like 220v will kill you unless you decide to hold on to the wire or you are sitting on the roof without harness
@@NocKme Not true at all, it can have lower voltage so that the light seems off, but a current of a lot of Amps, which is incredibly dangerous. Volts alone don't kill you, it's the resulting Amps that do the damage and that is related to the source's available Amps and the overall impedance of whatever it is it's traversing.
Well my grandpa used one when I was a kid 70 years ago and I still use one! Seems like the usual electrician stuff - too difficult and dangerous for an intelligent ‘common man’! Well care and intelligence has worked for me for 60 years so I’m sticking with that.
Nobody does a proper apprenticeship nowadays. Students learn stuff in tech. college but don’t learn common sense and survival in the real world. That’s why they all have to do specific ‘elf and safety courses and suchlike.
I think these things are quite safe unless visibly damaged (i.e. insulation compromised) or if the bulb broke somehow. Which is why when I want to make sure a circuit is *not* live I am using this device on a live circuit just beforehand to verify that it is working properly.
Below some voltage the light won't glow. You touch the wire and you get shocked ! 😀. At an isolated transformer it won't glow at any voltage ! You touch both wire and you get shocked ! 😀
Retired now, but have been using them all my life, never had or heard of a problem. But they tell you the most important thing 'Will I get zapped if I touch?' and small enough to always have clipped in your shirt. Even if you would get zapped, your hand would move back automatically, and it would be very short. (...and any electrician who's never been zapped shortly is a liar)
Using a multi meter might lead you to believe that a circuit isn't live when only the neutral wire is isolated while the live wire is still live. The good thing about a mains tester is that you use yourself to replace the neutral wire and avoid depending on it. At least, that's what I can come up with, correct me if I'm wrong. I'm not an electrician.
That is why you don't use multimeters in electrical installations! And electricians use proper 2-pole voltage testers. They can identify that problem, and indicate it. And 2-pole voltage testers must indicate the presence of dangerous potential even without a battery. In them the battery is only for the additional functions, but not for the basic functionality of indicating a dangerous voltage. And they have a low risk of operating error, compared to a multimeter. Also you don't need to look away from the point of measurement to check a value on a display. Multimeters have also a high internal impedance, so they will indicate "ghost" voltages between 60 and 100V. Usually created by capacitive coupling by a parall running still energized cable. But with the slightest load these voltages will collapse to zero. These neon indicator screwdriver voltage testers have the same issue btw. And if you are isolated, for example standing on a rubber mat, that voltage tester won't work.
Thats why us Electricians measure phase/phase, and both(or three) phase to earth. In norway we have 230V between the phases, and ~130V between phase and earth. If theres an outlet connected to a one-phase switch, and ONE phase is cut off, the 2nd phase could still be energised and if you touch it - and a i.e grounding wire you can get shocked
@@TheFenrirulfr Scandinavian countries usually have IT grids instead of TN or TT. So actually two lines instead of a line and an earthed neutral conductor. 230V between the lines. That system has the advantage that it can tolerate two faults before it isolates a circuit. But the disadvantage is: Harder to find faults. And the bigger the grid is, the harder it is to find faults. To get an electric shock you need to touch both lines at the same time. When touching one line you won't get an electric shock. But if your neighbour has a faulty water kettle, that one would be fault number 1, and you touch the line you can get shocked. Because due to the fault one of the lines become the earthed neutral (the one with the fault in it). IT grids are not referenced to earth potential, that is the reason the measurements against earth potential are nonsense and indicating bogus numbers. In most other countries IT grids are only used in small areas, for example in hospitals. There it helps to ensure safeguarding against failure.
I was trained to use a Drummond test lamp first and foremost. I also used a neon test lamp extensively, never got so much as the slightest tingle while using it - ever ! The likelihood of a foreign metal object falling into the body of a neon tester or the ingress of water into same is very remote.
That's why we were trained NEVER to assume dead until a further test showing live was taken.BTW, I have just checked the Drummond test lamp I was issued with and it is rated 80v to 500v, so definitely a bright light at 180v @@petextanky8421
It will light up at 80v and "glow" at lesser voltages. The instructions on Drummond test lamps clearly state that the lamp should be "proven" on known circuits before and after tests.@@petextanky8421
When made properly, these testers could be dangerous if not used for what they are intended for. The thing is, people (apparently including the author of the video) think these are intended to check whether the wires are energized or safe to work on. And that is absolutely wrong and dangerous assumption, many people got zapped when they thought the wires were off just because this did not appeared to light up. What this is really intended for is to verify which wire is the phase conductor or to positively check whether there is some power when something refuses to operate and that is all. Definitely not to verify the conductors are safe to touch or anything like that. In other words it only shows two states: "There is potential" when it lights up, and "I don't know" when it does not. None of those means "Safe to touch"...
@@TheDiligentDIYer1759 From the video I got an impression you are talking about "verify whether the wires are safe to work on" use, there I completely agree, the glow tester is not to be used. But when the task is "troubleshoot why the light does not work / where the wire is broken", it becomes the task these glowbottle testers are intended for. These "noncontact testers" are way too sensitive to identify the phase is really connected. They react even when there is broken phase wire or so - so when the place is crowded with wires, it is reacting all the time. They are supposed to be that way, because their purpose is to identify whether it is safe to work or not (as a double check after you switched the breaker off, of course). I know a V-meter is more reliable, but this is way faster. Plus sometimes you do not have access to a Neutral (like in light switches, if you want to identify whether the power even reaches them), so you even can not use the V-meter, while the non contact tester will respond to both wires even when the switch is disconnected or the wire broken, just due to coupling between those wires.
@@annaplojharova1400 Thank you for sharing this piece of information that was omitted in the video. That puts everything into a far more interesting perspective.
Had these types of screwdriver for decades,never had or heard of anyone getting hurt !!!!!! I will continue to use myn. Also most deaths are when the mains goes across the chest, hence why your told to keep one hand by your side when testing. The ironic thing is ,that using possible damaged probes, one in each hand for measuring, is far more dangerous,as it put the mains across the chest. . Scare hype for nothing pal.
Below some voltage the light won't glow. You touch the wire and you get shocked ! 😀. At an isolated transformer it won't glow at any voltage ! You touch both wire and you get shocked ! 😀
@@kenzo4Ever When was the last time you worked on a job ,with an isolating transformer? & who puts 2 fingers across anything,Seriously.A Neon lamp,has a strike voltageof around 90v !!! As an electronics engineer,you learn very quickly to check and double check every circuit,before touching it, its called having a brain,these days everything is given,but you cant teach common sense.
Been using one for years. One of the most useful electrical tools I have. Because you have to *touch* thescrewdriver on the conductor, it tells you exactly which one is alive. The proximity devices are ambiguous in this regard. Don't however use them to confirm something is *not* alive unless you have a nearby live sample to compare it with. The shock risk is minimal. One screwdriver I have lights faintly without actually touching it so even safer.
I have worked on electrical equipment from low voltage to 400kV both AC and DC for 60 years using every type of test equipment. This is the only item I carry at all times. Use it sensibly and it will save your life.
Neon screwdrivers have saved the day many times. Volt sticks are a liability, All I ever hear is .. damn thing sling it in the skip ,there is a neon in my box.
Volt sticks are unreliable, often show "live" on neutral cables or don't work at all; then there is the battery problem. Networks guys that I worked alongside despised volt-sticks.
Electrical systems have always the potential of being hazardous, however the fact that no one ever died of using such a screwdriver means something to me. The defaults you described are so very rare, that i never heard of something happening like that.
That device is called 'Tester' and its main purpose is to detect Phase and Neutral in a Single Phase Supply system and NOT 'live' or 'dead' wires. All wires are always assumed to be 'live'.
I recently purchased such a device and will definitely take extra care in future knowing what to look out for now in terms of how it might fail. I think working on 240V and using this device, even if it failed, would at worse give you a nasty zap. I did also purchase one of those plug-in mains testers and it immediately helped me solve 3 potentially dangerous wiring faults that had been in place for years in my home. I would totally recommend to use one of these if at all possible over and above the mains tester featured in this video as it can give you vital information immediately without even having to dismantle anything or directly expose you to any kind of danger.
First used these over 50 years ago. You can get quality ones (screwfix etc), which are waterproof and tough. If you understand how they work. they can be handy. There are not designed for "Testing", only for indicating there's a voltage present. They can also pick up Disconnected earths/cpc s and neutrals in a circuit if you understand how mains electricity works. They do have the they drawbacks, but what would expect for a couple of quid. Billions have been sold with few issues! I wouldn't use them in my job as an electrician.
Below some voltage the light won't glow. You touch the wire and you get shocked ! 😀. At an isslated transformer it won't glow at any voltage ! You touch both wire and you get shocked ! 😀
There is another danger. In the form of a virtual look-a-like 12V version used as car test lamp with a lead that comes out of the top of the screw driver to clip to ground in the car.. The two tools often co-exist in cheap tool kits. Looking so similar its possible to absentmindedly put the 12V test lamp into a 240V wall socket. A potentially very dangerous mistake.
@@rogerphelps99396 people disagree with you and my comment was aimed at novice DIYers who can be overconfident. You haven't seen the cheap Chinese Handyman screwdriver kits that mix 12volts test screwdriver with 240v neon test screwdriver. We see them in Sydney, and life and death I don't joke about.
My 2 cents, non contact pen is handy but always confirm with a multimeter if youre going to go hands on/perform work, and always test them on a known love circuit to confirm proper function
And you forgot a big problem, one I experienced once and that definitely convinced me never to use it again. The capacitive coupling between your body and the ground may not be enough to light the neon bulb! Once I wanted to intervene at home on a roller shutter switch located in height, I cut only the circuit of the roller shutter but there was also another cable for a lamp passed in the same places but on another circuit breaker. FYI, I’m on a fiber stepladder (not aluminum ), I take my test screwdriver, no light on all the connectors, I start to work until I take a discharge on the connector pair of the lamp cable. Being above ground on a non-conductive fiber stepladder, the neon bulb was not lit. I repeated the test and it is only by getting closer to the wall of the house or the floor that the bulb began to light...
As a Master Electrician i disagree as the most dangerous electrical tool .Used it for many years. But what is dangerous is NOT knowing what you are doing.
In over 50years of using one of these small electrical screwdrivers I have never had a problem except for the blade at the end when tightening up screws because it doesn’t seem to be hardened metal
The lamp works by ionizing the gas inside, there is no filament. Even if the lamp breaks as some said, that will not be enough to make proper contact inside and harm you. The only risk is not seeing the light or improper contact.
I used to use this since I was 12 years old to this day to check the old style Christmas lights lol. This tool is very useful for checking if there is current in a wire
The Non-contact voltage tester is WAY more dangerous. This thing some times will not trigger for some random reasons or will give you false positives. You should always double check with another tool (like the Neon screwdriver).
they give a 'beep' when a live circuit is detected ....and also give you an adrenaline boost, when you are working on wiring and they give the same damn 'beep' as they automatically shut down after a minute or so of being idle
I used one of these for years and they are quite safe provided (1) use it for mains voltages only. IE. No more than 250 volts. (2) do not use it for RF testing, like high wattage transmitter antennas.
Also called "widow makers". Banned from our site. Anyone caught with one has to return it to their van. Anyone caught using one is kicked off site for the rest of the week - second offence is a ban from site. You either use a voltage indicator and proving unit, or find another profession. The main issues with those toys are: The light can be unclear - as shown in the video The "test" voltage uses the body as the return path The resistor or neon could go faulty, and give a false "safe" indication. Probably others, but in general DIYers don't / won't listen to electrical advice. Volt sticks shouldn't be relied upon either. Always follow up proving dead with a voltage indicator and proving unit before work.
What sort of people work on your site? Does your site not have anything for regular checks of electrical equipment you use? What training is given? Do the people on your site have no common sense?
Working on Data Centre / CoLo / FLS build and upgrades. Yes, I (and my contractors have common sense, and for me - about 30 years experience woking in the industry at voltages from 54V to 132KV. . @@niv8880
These screwdrivers are great, perhaps in the hands of those not qualified they may be a hazard but with currents of a few hundred uA and resistance over 1MOhm there’re not gonna shock you.
I have a couple of these & they are very useful & reliable. The concept is sound enough as long as the component ratings & construction are such as to absolutely guarantee the current is going to be very small. I use mine according to the old high voltage working adage of always keep one hand in your pocket & stand on an insulated surface/ insulated boots etc.
@@odoohub5010 There is sufficient capacitive coupling between me & earth to allow enough current to flow to illuminate the neon light. It's not as bright as it is if I touch earth, but that buzzes my finger more than I'm comfortable with or feel is 100,% safe. Wouldn't work if it was DC without solid ground connection.
i threw that blue lap pen out last month as it failed after 2 years. i have another scheppach one it it was showing the cable was live and the lap one wasnt, even changed the batteries to see if that was the issue. I always try use 2 or 3 methods to test, not just 1 for this reason.
It seems to me that the author of the video is uncomfortable with the idea that he could be part of an electrical circuit. Many people have used these screwdrivers, but I have never heard of anyone getting electrocuted by them. However, I agree that they do not always correctly detect the absence of current and this can lead to a serious electric shock.
Blimey, I've been using these most of my life, since I was a kid. I'd just assumed if they were sold to perform the task, they'd be safe and suitable for doing so.
@@TheDiligentDIYer1759 i think if you look at the numbers of people hurt or killed by them, they are probably safer to use than driving a car. the only thing hes saying there are even safer options out there
1. Turn off the mains at the switch. 2. Take the fuse out of the fuse box. 3. Test if it is still live. Don't assume the circuit you are working on is wired to the correct fuse. I removed about 16' of lead sheathed wire having crumbling rubber covered wires inside when decorating. I tested them with a multimeter to make sure they were dead before pulling them out. There's still more going into the attic.
What a BS, the resistor inside the probe effectively prevents shock. These probes are still very popular, since they are foolproof to operate, cheap and very safe. A multimeter requires a battery, the correct ramge setting and the cables need to be plugged into the correct sockets. In addition the cables and tips can be worn or damaged over time. What is worst, you have to use both hands, what I try to avoid when working with mains voltage. If sonething goes wrong there is a definite circuit through my body. While when working only with one hand and wearing shoes with rubber soles, I would hardly recognize even if i touch 240V directly with my fingers My safety rule: always keep a hand in my backpocket.
That's why you should always test it on known mains before you start testing. I have used them for years and never had a problem, however I have had countless multimeter leads go Intermittent which can be far mor dangerous.
I've been using these since I was 15 and started to understand live/neutral difference. Never had a single, slightest issue with these. I always carry one on the jobs-I have that Kews meter, non touch pens and Stanley joist/cable sensor, but that pen is the simplest and fastest device.
I have been using my Vitrex made in Britain one for fifty years with no problems what so ever, would I replace it with an unbranded cheap one I seriously doubt it, a very useful tool but I only give it the slightest touch certainly would not hold there for more than a second or two, it also has a piece you can take out and put a plug fuse in to test the fuse.
Have used them as a DIYer for over 40 years, even back when we did electrical work that is not allowed any more. Isolate at the board (in my case in the garage), lock the garage and put key safe, double checks on circuit, and above all don’t work on a live circuit. An early blown fuse after cutting o a live wire, and you learn very quickly what not to do. Non contact tester isn’t always reliable in my experience.
Few points to make on this one: "dangerous" is relative. Can you point to a single recorded incidence of an injury from a mains testing screwdriver? I can point to a large number of injuries caused by the incorrect use of a handheld multimeter (Which can fail to show the voltage if you have the setting on it wrong (ie wrong terminals or DC setting) and can actually cause an arc flash over if the wrong settings and terminals are used and which often can have damaged leads due to careless use onlow votlage systems and those leads result in electricution of the user. Any "dual" probe tester also carries a risk as those probes can causes shorts in the EUT and necessarily makes those devices a double hand use, which means a current path more likely to cross the users heart It's worth noting that the neon bulb used is actually enough to prevent a significant shock on it's own as its ionisation current is very low (hence its use) it is also very very robust and not easily damaged. IME, the worst thing about mains testing screwdriver is actually the fact it IS a screwdriver, so people are tempted to use them for other things other than mains testing, often damaging the insulation on the shaft, which can leads to user shocks should the user hold the device below the handle The no1 reduction in risk from "proving dead" is making sure you can get a positive identification of the high voltage potential before you attempt to isolate the circuit. IE if you isolate the circuit and use a mains testing device that does not have a proving unit (ie martindale tester etc) you never see a positive result that proves your testing is set up correctly and working as expected. So i always make sure i can measure and get a "live" result, then isolate and make sure i get a "dead" result..... Sure, for commercial use you need a proper industry standard tester, but for DIY i'd much rather someone used a testing screwdriver (having proved they get a positive result first before isolation as mentioned) that just guessed....... ;-)
Thanks for the video. It's good to make sure we are safe. I never use that tester again and as you have pointed out, I got myself both the better qualiter tester. Better to spend some money and be working safe.
The non-contact testers work on the electric field NOT the magnetic field. The magnetic field is a property of current flow yet these voltage testers work even when no current is flowing.
I believe I had the first of this type of tester and it worked fine. That was quite a while ago. Now I use an absolutely safe current tester I made myself to test outlets and detect the presences of wiring within walls.
I prefer the screwdrivers with an LED, transistor and a couple of watch batteries, they are brighter and much more sensitive. It can be checked before every use by touching both the tip and cap with a finger, it can also be used for testing continuity of fuses and lamps.
We are using this type of tiny tester since in very beginning so how it becomes dangerous. Also we have digital probe like pen tester. You bring new theory may be you are promoting your new tester.
I'm amazed they still exist. Sometime back I got one from Poundland that works like this, but can also work contactless by pointing the top towards whatever it is. Works really well too.
Very common tool in eastern europe, for decades. Still very much used. Like any tool, needs to be used properly. Also bites if you happen to touch a grounded part while probing. Unfortunately new models seem to come with physically small resistor.
If you had ever read any old electrician education materiel from eastern Europe you will know that this is not the right tool to use, the right tool is a tester like the one shown at 1:35 in a more bulky variant, but one thing is what people is taught, an other thing is what they do in reality, they sadly often reach out for the easy fix solution.
@@K2teknik. Do you remember how those old voltage testers with 2 probes worked in 50s-80s? They were passive, without batteries and LEDs. It was just coil with core on spring. Impedance of this coil was very low. So if you dropped one probe, you could get shocked easy. Screwdriver tester was in fact much safer. And there was no way to test just one wire if it is life without connecting second probe to good ground.
Thoroughly agree! You'll aways get people saying they've used one for years and they're quite safe, however, these are often the people with the least knowledge of electricity and its dangers. They'll assume that if it doesn't light up, then the circuit is not live. Bet they don't first test it on a known live circuit to check its working ok, as you would always use a proving unit on a two prong tester before use. I remember as a 12 year old pushing one into a metal clad socket in the school physics lab, shorting it to earth and creating a loud bang and flash. Needless to say, the physics teacher was not impressed, telling me "A little knowledge is a dangerous weapon", how right he was! stay safe!
Do you know how a neon bulb works? It is basically a filament-less bulb. Which means there is a break in the line. It's been used for probably one century already and the risk is close to zero. I'll tell you, it is much more dangerous to not have it when you need it
Neon conducts electricity, the bulb would need to blow to stop current passing through. In the scenarios I mentioned like water ingress, having neon bulb wouldn’t make any difference. Thanks for watching!
I think these work based of the AC as well as the grounds. Because if you have thick rubber shoes on and isolated from ground would the light still turn on ?
For me touching the end with an insulated tool didn’t work, I don’t think it would work if you were fully insulated from the ground either. Thanks for watching!
@@TheDiligentDIYer1759 can you the contact pen with lipstick balm fat on your finger to reduce a potential shock from the pen or wont the pen work at all then?
I've used and continue to use all three items you've reviewed. I take your point but I think it's extreme to say the screwdriver type tester is very dangerous. Personally I prefer the non contact tester as it's so quick and accurate and detects current in cables without removing any sleeving to expose the copper cores. Also many non contact testers have an LED light so you can see into dark spaces where many consumer units are located. Mine also has a green laser pin point light. So, overall many benefits over the old style tester. Thanks for yor video.
Hi. I was interested in your saying the red probe on a multimeter should be put into the COM. I did a search and other sites say the black probe goes into the COM. So who is right?
Saying the red probe goes to COM is the 13th stroke of the clock, it casts doubt on all the rest. And advising a multimeter is dubious, there are a lot of cheap ones about that are not properly approved for mains voltage. I can see the argument against neon screwdrivers but you have to keep risks in proportion. I would only use one as a backup check. And two probe testers can give the wrong answer in some situations like lighting circuits.
You are right, don’t have one neon in my toolbox but 3 all day long, and let me brake down the news for you . If you are dealing with soak in water tools at electrical installations and repairs you shouldn’t even exist in this world and trade. My opinion
The problem with non contact is that you can get a lot of false positive because of the cross talk in the wires if there's two out of phase and a neutral/ground
This is very useful to know. I'm the most amateur of amateur DIYer and I've had one of these for at least 25 years and have never used it to test for current. The blade is obviously designed for the types of screws you find in electrical components and battery panels on toys etc so it's good to have around. As it's been rattling around my toolbox/kitchen drawer of doom for decades, there's a good chance that void had been bridged and I wouldn't have known to check. Thanks! By the way, can you use a multimeter to check if it's in working order?
You could put a multimeter with a probe attached to the top and bottom, then measure resistance. It should be very high or give no value at all, if it gives something low, then it’s dangerous to use. Still id just get a non contact tester to be safe. Thanks for watching!
I always turn off the circuit when testing and then turn back on to verify tool is reading correctly. Final turn off verifies everything is safe to work on. I agree 100% that contactless is always the safer way to go.
When I started work as an apprentice electrician in 1971 I had one of these. The charge hand took it off me and threw it in the bin. He then gave me a proper voltage tester. I have never used a screw driver type voltage tester since and never will. I have never understood why these have not been banned, especially with the amount of perfectly safe test gear that is available today.
A neon tester will detect the hazardous condition where all available contacts have become live. The professional testers, multimeter or test lamp will declare the condition safe.
@u1zha Maybe, but In fifty years I never go thrown across the room because a "dead" circuit wasn't I know of more than one electrician who couldn't say that after using one of those testers.
That only becomes dangerous if it gets submerged in water or in some cases if you where bare feet on a wet floor the problem with the touchless ones is they can only tell is there is power (which i already know there is) and not which wire is hot and neutral in order to wire the outlet correctly sometimes the wires are not color coded and even if they are i always check first.
while i agree that these should not be used for proving live/dead conductors, and for a quick indication a non contact tester will suffice. i use 1 for finding the live wire as normal sockets here dont have a defined live and neutral side. and for my old lathe to run in the right direction i need to know which is which ( and yes i'm setting up a cee socket so its always correctly hooked up later on havn't had the time and space to do so yet ). do you have any insights on how to cheaply identify the live conductor?
Difficult to know without seeing your exact situation, but a stop gap solution could be a cee to 3 pin converter, they’re pretty cheap and easy to come by. Thanks for watching!
@TheDiligentDIYer1759 yup thats exactly what iv been doing, and have labeled a few sockets with live an neutral side. But confirming whether the person before me actually followed color codes is always the gues. What affordable tool would you recommend for reliably differentiating live and neutral. My non contact isn't to clear about it and doesn't seem like a reliable way to me.
I'm a heating engineer. I have to say that I have been using 'neon screwdrivers' for 50 years (just about to retire) with zero problems. I worked with 45 other engineers...and I've never heard of anyone getting a shock from them. I don't like my 'voltstick', as I find that is unreliable, so is potentially dangerous to trust it. But the 'neon'...no issue.
best tool ever invented, I think this would be my number one choice always. I'm so used to it, I wouldn't even start changing a socket if I don't have it.
Think you are all missing the point. They should be used as a probe, ie should have a pointed end. Most of them dont, they become flat head screwdrivers and levers by diyers, which are over stressed causing a crack in the shaft, especially cheapo models. Current could pass resistor into crack onto a sweaty hand and there lies the problem. Simples.
i havent used one of those for years , im not a pro but have done a few houses in my time ( always have had my work checked by a pro) and i have never compromised on my safety equipment and a few years ago i got a Fluke 1AC II VoltAlert - Non-Contact Voltage Detector Pen which wasnt cheap and i trust it BUT if someone is buying one of these things please check its the right voltage range , i didnt even think about it when i bought it and luckily i bought the right one , it was only later that i found out that they do different ranges and if you get the wrong one then it can tell you its dead when in fact its hot , especiallythe cheaper versions may not be as described love your videos
Great, so if you lose your neutral but still have a live, your "professional" 2 pronged tester says it's "dead" while it's clearly NOT. Stick to house bashing.
This is an awesome video! Thanks in particular for explaining the failure modes of the pen testers. I’ve always felt they were potentially dangerous, but wasn’t sure how they could fail exactly. Also, you said two things about the NCVT that are slightly wrong. 1) They sense the electrostatic field, not the electromagnetic field. 2) They do in fact use your body as the return path, and if your boots are too insulating, as you said in another comment about the pen. But they will also fail to work if you’re too far away from the ground, like up on a ladder. I’ve been up on an 8-foot fiberglass ladder and found them to still work, but I’m not sure how much further I could get.
@@TheDiligentDIYer1759 Any comments on my observations about the height above ground limitation on the NCVT? I haven’t been able to test the statements I’ve read on the issue and am wondering if you’ve heard anyone talk on the subject.
@@jumper233 best to use the right tools to check for voltage rather than toys, as electric is not something to play with. Approved voltage indicators etc. When working on 415v etc I wouldn't even imagine getting a toy to test for power. Not these old school DIY gadgets. Heard they have potential to shock but could be hearsay. VDE rated screwdrivers and approved rated voltage indicators. Decent multimeters etc. That's my opinion. Maybe I'm wrong🤔, what do you think
No doubt there will be moves to ban them. Depends on how used. I was wiring up a two way switched lighting circuit for disabled neighbour, so isolated what I thought was the relevant fuse channel. It wasn't possible to shut off supply at the distribution board, as neighbour felt cold. A 'shared neutral' error meant I could not do a DVM check. While working, the thing lit up, saving me from a shock. These should be for alert purposes only but not as a substitute for a multimeter, I would agree.
I've never had any problems with those testers thru my 30y career. Neither with the cheap one nor with the certified one. I even made my own testers from spare parts, which had extended wires, for testing in two points 400V, or 230V (with a person as a neutral potential). The main thing to remember when working with these types of testers is that BEFORE you put the tester on the wire you are testing - FIRST touch any point that you know is live (to make sure the tester is working), and ONLY THAN touch that point you are examining.
the stuff complete the circuit by grounding through your body. this is fine for casual electric work i.e. wiring your house power socket, checking the live/neutral for active current. as long as the current is not above kilovolt range, you're fine as the current passing through you is negligible.
I found the non-contact tester gave me a false positive when I changed a ceiling light pendant. It indicated that the wiring was live but in fact it was picking up some induced current. I had the MCB turned off. I checked with a neon type screwdriver similar to the one examined. I had previously checked it indicated live reliably when the MCB was turned on. I believe the MCB isolates only the live conductor and not the neutral.
Testers are fine as long as you don't use them as screwdrivers! I forgot that I had broken it trying to unscrew a device I was trying to fix. Then days later trying to check an outlet, I got the shock of a lifetime. Thankfully the spring coil and other contact resistances still had enough impedance to reduce the current.
It's harmless if it is in it's original condition. The video showed potential fault possibilities which could render it dangerous. I think the possibility of moisture ingress was illuminating 🌩
As a retired signalling tech support engineer who used to calibrate test kit from meggers to flukes too live line testers. Any meter , volt pen or other circuit tester Unless calibrated at least annually on catibrated test machine any item that is supposed to give accurate readings or safe to touch test equipment will have the potential to be wrong. Sure use a live line tester but for me on sockets for example plug in a lamp turn off at the consumer unit if the light goes out its a good bet the circuits dead . Double check with your uncalibrated diy test probe and you can be fairly sure its got no power. I prefer meters to probes but still have a good Fluke non contact one that picks up power by just touching the socket housing its ultra sensitive but not as cheap as the diy prode drivers at around £25
Non-contact testers are great and I have 3. However, if you value your Spouse and children, then definitely get a Mains Testing Screwdriver. They can do what non-contact cant. They can test screws of switch boxes and socket fittings. For instance, when we moved into our new house, two separate mains light switches had the live connected to the screws on the switch housing. This had happened because the live was shorting locally to the metal casing behind, no Earth fitted. This would have been impossible to test with a non-contact type, as it would be swamped by voltage from cable. Of the thirty odd sockets and switches in our new house, only two had this problem, but it only needs one to ruin someone’s day.
I mean the argument that something can get inside is quiet pointles, the bottom part and top part are detachable and one of your basic responsibilities is to check your equipment before using it, you can open it up and clean. Second thing is that some of them do not contain spring alone but spring and fuse. The spring wire tho should burn and shouldnt allow you to receive full voltage by design. Another important thing is rating of the tool which needs to be checked as 230-250V in sockets is usually 9A or 16A, anything like 25A and more and the producer of the tester themselves do not recommend to use it.
I've never seen this particular design. The one I've used had an old long fuse in it, not a globe. It also had a wire, which inserted into where the button is on this one, to an earth clamp.
One thing the non-contact pens really excell at is testing those screw-in type fuses... And I do know the coloured tab in the visible end of the fuse should come off when it goes... But often they don't. And sometimes the fuse holder actually has a little hole where one can put a probe into. But then again, often there is no hole. I have heard that sometimes some people have actually even broken the glass on those things to stick a probe in. But a contactless pen works just fine just by tapping the glass with it. I remember a few times there were just huge panels with row after row of fuses. And obviously they should have been properly marked and all, but like so many times, there were little to no markings and sometimes things have been changed and while there might be a label saying one thing, it might be just mislabeled at that point. While the contacless is not perfect by any measure, it did speed up diagnosing the problem quite a bit. Now some people have pointed out potential issues with basically any type of tester... And yes, nothing is perfect. Personally I don't trust contacless, because they are notorious for giving plenty of false positives and negatives. So I consider them more of a diagnostic tool, that can help to identify potential issues. And one another thing I could also point out is one day I was doing this basic "health" test on a C-128 PSU... After all CBM power bricks are known to fail in ways that would fry electronics. It literally took a while for me to find any trace of electrical power on the connector pins. But ultimately I was able to measure more than double voltage on DC-bus. The reason why I had trouble finding any voltage was likely due to contact surfaces not being entirely clean. And mind you, they did look like pretty clean just by looking at it. But to get good contact with the probes it required some scraping around to get past all the impurities that had accumulated on the surface. While that was about fairly low voltage DC, similar things can happen with grid level AC as well... If you wan't to be completely sure, you should be able to detect power on and only after that verify that the power was disconnected. And when in doubt, turn off everything. When dealing with devices that are connected to a socket, pulling the plug out of the socket is simple and sure way to make sure it is not connected... But even when fully disconnected, one should remember that capacitors can potentially store lethal charge, and while usually devices that have capacitors have drain resistors for safety... But it is important to understand that should a drain resistor fail, literally the only symptom could be the fact that capacitors won't drain. When dealing with potentially lethal things, one should never, under any circumstances just assume anything. I allways say that one should treat any piece of circuit as if it was live, untill proven otherwise. And like I said allready, every kind of tester and detector comes with flaws. Contactless might give false results either way. And any tester that does rely on a probe contact, might be thrown off by poor contact. Just because you pressed the probe against something, does not guarantee good connection. As for those screwdrivers... I would agree on that. While other types might potentially have their own faults, having something that is designed to use you as a part of a circuit, is in my humble opinion, just looking for trouble. Maybe one could use that as a "last line of defence". But would I recommend those as primary voltage detectors? Most certainly not. And as for potential safety concerns on multimeters and voltage testers... It should be obvious that one should pay attention to their condition. If there is any sign of damage to the insulation, one should stop using them immediately.
I have been using these screwdriver testers for many years and never had a problem, I’ve also used the volt pen which sometimes did me a false reading.
I've always wondered how they work and had one as a kid, but was clueless when seeing only one terminal, so didn't know how the circuit would be complete. This is very good publicity of stating the safer alternatives as you don't fully know the volts and amps. You don't know if the resister would blow or accept the current if too high. Imagine the dangers of it being 30A! It would feel unpleasant!
I do a lot of switchroom maintenance and there is always a risk of multiple sources of electrical energy that can feed back into the LV switch gear (UPS or gen sets). If I find anyone testing for dead with one of those screwdrivers or a volt pen I remove them from site. The HV side I test and then issue a permit when proved safe to work on. The LV side a tester and proving unit must be used!
This one is actually a higher end model if you can say that😅 the even cheaper knock offs often have a cylindrycal carbon-like hard pressed little tablet instead of an actual resistor and the button can not be a button, but a rivet to contact the spring 😅
You are mistaken in the principle of operation of the indicator screwdriver - the current does not go through the user to the ground, the user is a capacitor creating an oscillatory circuit. It is trivial to check - put on thick rubber shoes and the screwdriver will still work.
I have been using these for 50 years without any issue. The are 2 rules : 1. If the screwdriver lights up the contact point is live so take proper precautions. 2. If the screwdriver does not light up, do NOT assume the contact is dead.
Thanks for watching!
Rule 3: Don't bet your life on a cheap 0,25W Resistor if you can help it.
The old ones had far beefier ones and were made better but still.
Now there are options which are just as simple to use without making yourself part of the circuit.
@@timhartherz5652 Older ones were made with resistors from tube era. Those were often rated for 1kV.
As a younger man I've tolerated many 220v electrical shocks (up to 20KV when working with CRTs) Accidents happen. As an older man with a a heart condition, I treat every wire as if it was live (unless I'm actually in unobstructed sight of both ends). The latter has, again been a life-saver. Never touch the wires, keep one hand away and stand on rubber mats.
They will also light up from capacitance if a cable is not earthed. They have saved me from many shocks over the years.
You hear people saying they're dangerous and/or unreliable all the time, but are there actually any reports of anyone ever heing harmed by one of these? I've been using them all my life and have no intention of stopping. They are incredibly useful and I would trust one of these over a contactless volt tester any day.
It is exactly what I was thinking. I am a professional electrician and it has never failed me nor have I had any problems.
Ive heard stories of people getting shocks, but it would be very hard to get data as it’s generally rare a shock like this would require a hospital visit.
I personally think anything using you as part of the circuit is a terrible design, but everyone is entitled to an opinion. Thanks for watching!
Its more the problem of cheap parts, the 1/4watt resistors and is not rated for these voltages, it can fail open or short-circuit for instance. Poking a 400volt connection is probably also not a good idea. Etc there are tomanny possible failure modes. If you know what you're doing it's most likely fine but for the home gamer it's not something to rely on. I'd say because when using it you are part of the circuit now thankfully almost every installation here is rcd protected. As a funny side not my last step before grabbing a conductor is using the back of my hand as a last live check😅
@@TheDiligentDIYer1759 er, you are always part of a circuit because you absolutely always have a path to ground! Everything is a conductor, it's only the absolute level of impedance that varries.... lol ;-)
And you want to short yourself to 230 volts with no control. Good luck
I saw a fellow Apprentice receive a horrendous electrical shock using something identical to this
Don't
Back in the Eighties when I was training as a Theatre Technician, one of our lecturers had got a shock through a 400 volt neon tester. It SAVED HIS LIFE. While handling a lantern that was running on one phase, it shorted onto the motorised truck that it was mounted on. The truck was on another phase. The tester melted, and every hair on his body burnt off, but he lived. Because of that tester.
Glad to hear it lived, thanks for watching!
@@TheDiligentDIYer1759 It?
It said max 260 or 300 volt…
A good electrician know their tools…
One of these may have saved my life. My son had a non working 13A socket in his house. I checked it with a multimeter and it showed as dead. I used one of these screwdrivers and it illuminated showing it was live. On further investigation I found the earth and neutral were both disconnected somewhere leaving only the line connected.
Non contact volt pen is best in my opinion, thanks for watching!
Below some voltage the light won't glow. You touch the wire and you get shocked ! 😀.
At an isolated transformer it won't glow at any voltage ! You touch both wire and you get shocked ! 😀
Never trust an old installation.
I use a wire finder, as it detects electricity as well and reacts to small voltage and you don't need a closed circuit. In combination with a multi meter you then can find issues with a wire.
non-contact indicators often give false positives. they just glow, especially if there are a lot of wires and they are close, and you cannot know which wire is hot and which is disconnected. Non-contact indicators use a battery, and it often runs out, and even in certified indicators the sensitivity drops; this has happened to me often. Sorry, but the indicator screwdriver is a reliable, life-tested device.
and the most reliable thing is a dial multimeter.
I have been using my device for more than 50 years. It has never failed, never broken anywhere, never had any foreign matter intrude into it and has always worked. Yes it can be hard to see the neon at times but it has always shown me when a wire or contact is live to mains voltage. Your fears may be sound scientifically but the chance of it happening is extremely slim. Using the bared-ended metal spikes of multimeter probes is far more awkward and way more dangerous.
Thanks for sharing your opinion
Below some voltage the light won't glow. You touch the wire and you get shocked ! 😀.
At an isslated transformer it won't glow at any voltage ! You touch both wire and you get shocked ! 😀
@@kenzo4Ever well if you are dealing with a voltage that won't light it up then the shock won't do much either. It's not like 220v will kill you unless you decide to hold on to the wire or you are sitting on the roof without harness
@@NocKme Not true at all, it can have lower voltage so that the light seems off, but a current of a lot of Amps, which is incredibly dangerous. Volts alone don't kill you, it's the resulting Amps that do the damage and that is related to the source's available Amps and the overall impedance of whatever it is it's traversing.
Well my grandpa used one when I was a kid 70 years ago and I still use one! Seems like the usual electrician stuff - too difficult and dangerous for an intelligent ‘common man’! Well care and intelligence has worked for me for 60 years so I’m sticking with that.
Thanks for watching
Nobody does a proper apprenticeship nowadays. Students learn stuff in tech. college but don’t learn common sense and survival in the real world. That’s why they all have to do specific ‘elf and safety courses and suchlike.
This tester is no more dangerous than any other tester. You are talking hypothetically, that can be said whatever you use.
Thanks for sharing your opinion
Are you serious? What’s the CAT rating on those pen testers? 😂. Seriously, this is a big deal. You may get away with it for basic home use.
I think these things are quite safe unless visibly damaged (i.e. insulation compromised) or if the bulb broke somehow. Which is why when I want to make sure a circuit is *not* live I am using this device on a live circuit just beforehand to verify that it is working properly.
Thanks for watching!
Below some voltage the light won't glow. You touch the wire and you get shocked ! 😀.
At an isolated transformer it won't glow at any voltage ! You touch both wire and you get shocked ! 😀
I do the same. Had no problem for so many years.
Retired now, but have been using them all my life, never had or heard of a problem.
But they tell you the most important thing 'Will I get zapped if I touch?' and small enough to always have clipped in your shirt.
Even if you would get zapped, your hand would move back automatically, and it would be very short.
(...and any electrician who's never been zapped shortly is a liar)
Thanks for watching!
Using a multi meter might lead you to believe that a circuit isn't live when only the neutral wire is isolated while the live wire is still live. The good thing about a mains tester is that you use yourself to replace the neutral wire and avoid depending on it.
At least, that's what I can come up with, correct me if I'm wrong. I'm not an electrician.
Thanks for watching!
That is why you don't use multimeters in electrical installations! And electricians use proper 2-pole voltage testers. They can identify that problem, and indicate it. And 2-pole voltage testers must indicate the presence of dangerous potential even without a battery. In them the battery is only for the additional functions, but not for the basic functionality of indicating a dangerous voltage. And they have a low risk of operating error, compared to a multimeter. Also you don't need to look away from the point of measurement to check a value on a display.
Multimeters have also a high internal impedance, so they will indicate "ghost" voltages between 60 and 100V. Usually created by capacitive coupling by a parall running still energized cable. But with the slightest load these voltages will collapse to zero. These neon indicator screwdriver voltage testers have the same issue btw. And if you are isolated, for example standing on a rubber mat, that voltage tester won't work.
Thats why us Electricians measure phase/phase, and both(or three) phase to earth.
In norway we have 230V between the phases, and ~130V between phase and earth. If theres an outlet connected to a one-phase switch, and ONE phase is cut off, the 2nd phase could still be energised and if you touch it - and a i.e grounding wire you can get shocked
@@TheFenrirulfr Scandinavian countries usually have IT grids instead of TN or TT. So actually two lines instead of a line and an earthed neutral conductor. 230V between the lines. That system has the advantage that it can tolerate two faults before it isolates a circuit. But the disadvantage is: Harder to find faults. And the bigger the grid is, the harder it is to find faults.
To get an electric shock you need to touch both lines at the same time. When touching one line you won't get an electric shock. But if your neighbour has a faulty water kettle, that one would be fault number 1, and you touch the line you can get shocked. Because due to the fault one of the lines become the earthed neutral (the one with the fault in it).
IT grids are not referenced to earth potential, that is the reason the measurements against earth potential are nonsense and indicating bogus numbers.
In most other countries IT grids are only used in small areas, for example in hospitals. There it helps to ensure safeguarding against failure.
Yup
I was trained to use a Drummond test lamp first and foremost. I also used a neon test lamp extensively, never got so much as the slightest tingle while using it - ever ! The likelihood of a foreign metal object falling into the body of a neon tester or the ingress of water into same is very remote.
Thanks for watching
A Drummond test lamp won’t light up if you have low volts like 180v and still plenty to give a shock if you assume dead !
Things like that would be blindingly obvious.
That's why we were trained NEVER to assume dead until a further test showing live was taken.BTW, I have just checked the Drummond test lamp I was issued with and it is rated 80v to 500v, so definitely a bright light at 180v @@petextanky8421
It will light up at 80v and "glow" at lesser voltages. The instructions on Drummond test lamps clearly state that the lamp should be "proven" on known circuits before and after tests.@@petextanky8421
When made properly, these testers could be dangerous if not used for what they are intended for. The thing is, people (apparently including the author of the video) think these are intended to check whether the wires are energized or safe to work on. And that is absolutely wrong and dangerous assumption, many people got zapped when they thought the wires were off just because this did not appeared to light up.
What this is really intended for is to verify which wire is the phase conductor or to positively check whether there is some power when something refuses to operate and that is all. Definitely not to verify the conductors are safe to touch or anything like that.
In other words it only shows two states: "There is potential" when it lights up, and "I don't know" when it does not. None of those means "Safe to touch"...
I don’t think they should be used at all. I make that clear in the video.
@@TheDiligentDIYer1759 From the video I got an impression you are talking about "verify whether the wires are safe to work on" use, there I completely agree, the glow tester is not to be used.
But when the task is "troubleshoot why the light does not work / where the wire is broken", it becomes the task these glowbottle testers are intended for.
These "noncontact testers" are way too sensitive to identify the phase is really connected. They react even when there is broken phase wire or so - so when the place is crowded with wires, it is reacting all the time. They are supposed to be that way, because their purpose is to identify whether it is safe to work or not (as a double check after you switched the breaker off, of course).
I know a V-meter is more reliable, but this is way faster. Plus sometimes you do not have access to a Neutral (like in light switches, if you want to identify whether the power even reaches them), so you even can not use the V-meter, while the non contact tester will respond to both wires even when the switch is disconnected or the wire broken, just due to coupling between those wires.
@@annaplojharova1400 Thank you for sharing this piece of information that was omitted in the video. That puts everything into a far more interesting perspective.
Had these types of screwdriver for decades,never had or heard of anyone getting hurt !!!!!! I will continue to use myn. Also most deaths are when the mains goes across the chest, hence why your told to keep one hand by your side when testing. The ironic thing is ,that using possible damaged probes, one in each hand for measuring, is far more dangerous,as it put the mains across the chest. . Scare hype for nothing pal.
Thanks for sharing your opinion
Below some voltage the light won't glow. You touch the wire and you get shocked ! 😀.
At an isolated transformer it won't glow at any voltage ! You touch both wire and you get shocked ! 😀
@@kenzo4Ever When was the last time you worked on a job ,with an isolating transformer? & who puts 2 fingers across anything,Seriously.A Neon lamp,has a strike voltageof around 90v !!! As an electronics engineer,you learn very quickly to check and double check every circuit,before touching it, its called having a brain,these days everything is given,but you cant teach common sense.
@@enoz.j3506
OK.
The difference is that I care to warn whereas You dare to insult ! 😀
@@kenzo4Ever Warning fools, was never my strong point.
Been using one for years. One of the most useful electrical tools I have. Because you have to *touch* thescrewdriver on the conductor, it tells you exactly which one is alive. The proximity devices are ambiguous in this regard. Don't however use them to confirm something is *not* alive unless you have a nearby live sample to compare it with. The shock risk is minimal. One screwdriver I have lights faintly without actually touching it so even safer.
Thanks for watching!
I have worked on electrical equipment from low voltage to 400kV both AC and DC for 60 years using every type of test equipment. This is the only item I carry at all times. Use it sensibly and it will save your life.
Neon screwdrivers have saved the day many times. Volt sticks are a liability, All I ever hear is .. damn thing sling it in the skip ,there is a neon in my box.
Thanks for watching!
Volt sticks are unreliable, often show "live" on neutral cables or don't work at all; then there is the battery problem. Networks guys that I worked alongside despised volt-sticks.
Both have their place and are useful.
These are gold for finding out if you have power on wires that are close to each other, something that a NCV tester cannot do.
Electrical systems have always the potential of being hazardous, however the fact that no one ever died of using such a screwdriver means something to me. The defaults you described are so very rare, that i never heard of something happening like that.
Thanks for watching!
That device is called 'Tester' and its main purpose is to detect Phase and Neutral in a Single Phase Supply system and NOT 'live' or 'dead' wires. All wires are always assumed to be 'live'.
I recently purchased such a device and will definitely take extra care in future knowing what to look out for now in terms of how it might fail. I think working on 240V and using this device, even if it failed, would at worse give you a nasty zap. I did also purchase one of those plug-in mains testers and it immediately helped me solve 3 potentially dangerous wiring faults that had been in place for years in my home. I would totally recommend to use one of these if at all possible over and above the mains tester featured in this video as it can give you vital information immediately without even having to dismantle anything or directly expose you to any kind of danger.
Thanks for watching!
First used these over 50 years ago. You can get quality ones (screwfix etc), which are waterproof and tough. If you understand how they work. they can be handy. There are not designed for "Testing", only for indicating there's a voltage present. They can also pick up Disconnected earths/cpc s and neutrals in a circuit if you understand how mains electricity works. They do have the they drawbacks, but what would expect for a couple of quid. Billions have been sold with few issues! I wouldn't use them in my job as an electrician.
Good points! Thanks for watching!
Below some voltage the light won't glow. You touch the wire and you get shocked ! 😀.
At an isslated transformer it won't glow at any voltage ! You touch both wire and you get shocked ! 😀
There is another danger. In the form of a virtual look-a-like 12V version used as car test lamp with a lead that comes out of the top of the screw driver to clip to ground in the car.. The two tools often co-exist in cheap tool kits. Looking so similar its possible to absentmindedly put the 12V test lamp into a 240V wall socket. A potentially very dangerous mistake.
You have to be joking, don't you?
@@rogerphelps99396 people disagree with you and my comment was aimed at novice DIYers who can be overconfident. You haven't seen the cheap Chinese Handyman screwdriver kits that mix 12volts test screwdriver with 240v neon test screwdriver. We see them in Sydney, and life and death I don't joke about.
Thanks for watching!
been there done that, luckily I felt the tingle and let it go, haven't used these type since
My 2 cents, non contact pen is handy but always confirm with a multimeter if youre going to go hands on/perform work, and always test them on a known love circuit to confirm proper function
Thanks for watching
And you forgot a big problem, one I experienced once and that definitely convinced me never to use it again. The capacitive coupling between your body and the ground may not be enough to light the neon bulb! Once I wanted to intervene at home on a roller shutter switch located in height, I cut only the circuit of the roller shutter but there was also another cable for a lamp passed in the same places but on another circuit breaker. FYI, I’m on a fiber stepladder (not aluminum ), I take my test screwdriver, no light on all the connectors, I start to work until I take a discharge on the connector pair of the lamp cable. Being above ground on a non-conductive fiber stepladder, the neon bulb was not lit. I repeated the test and it is only by getting closer to the wall of the house or the floor that the bulb began to light...
Good points, thanks for watching!
I was going to ask if it would still work if you were in rubber trainers or boots.
@@GDGRailway47712Yes, it would work
As a Master Electrician i disagree as the most dangerous electrical tool .Used it for many years. But what is dangerous is NOT knowing what you are doing.
Thanks for sharing your opinion
In over 50years of using one of these small electrical screwdrivers I have never had a problem except for the blade at the end when tightening up screws because it doesn’t seem to be hardened metal
We all do it but they're not intended for use as as screwdriver Don't even ask why they therefore make them with a flat end rather than a point
The lamp works by ionizing the gas inside, there is no filament. Even if the lamp breaks as some said, that will not be enough to make proper contact inside and harm you. The only risk is not seeing the light or improper contact.
I used to use this since I was 12 years old to this day to check the old style Christmas lights lol. This tool is very useful for checking if there is current in a wire
The Non-contact voltage tester is WAY more dangerous.
This thing some times will not trigger for some random reasons or will give you false positives.
You should always double check with another tool (like the Neon screwdriver).
Thanks for sharing your opinion
they give a 'beep' when a live circuit is detected ....and also give you an adrenaline boost, when you are working on wiring and they give the same damn 'beep' as they automatically shut down after a minute or so of being idle
I used one of these for years and they are quite safe provided (1) use it for mains voltages only. IE. No more than 250 volts. (2) do not use it for RF testing, like high wattage transmitter antennas.
Also called "widow makers".
Banned from our site. Anyone caught with one has to return it to their van. Anyone caught using one is kicked off site for the rest of the week - second offence is a ban from site.
You either use a voltage indicator and proving unit, or find another profession.
The main issues with those toys are:
The light can be unclear - as shown in the video
The "test" voltage uses the body as the return path
The resistor or neon could go faulty, and give a false "safe" indication.
Probably others, but in general DIYers don't / won't listen to electrical advice.
Volt sticks shouldn't be relied upon either. Always follow up proving dead with a voltage indicator and proving unit before work.
Glad to hear, thanks for sharing and thanks for watching!
What sort of people work on your site? Does your site not have anything for regular checks of electrical equipment you use? What training is given? Do the people on your site have no common sense?
Working on Data Centre / CoLo / FLS build and upgrades. Yes, I (and my contractors have common sense, and for me - about 30 years experience woking in the industry at voltages from 54V to 132KV. . @@niv8880
You don't seem to have any relationship with electricity or any experience in the field.
These screwdrivers are great, perhaps in the hands of those not qualified they may be a hazard but with currents of a few hundred uA and resistance over 1MOhm there’re not gonna shock you.
I have a couple of these & they are very useful & reliable. The concept is sound enough as long as the component ratings & construction are such as to absolutely guarantee the current is going to be very small. I use mine according to the old high voltage working adage of always keep one hand in your pocket & stand on an insulated surface/ insulated boots etc.
Thanks for watching!
If you stand on an insulated surface, how then will you be grounded for the tester to work?
@@odoohub5010 There is sufficient capacitive coupling between me & earth to allow enough current to flow to illuminate the neon light. It's not as bright as it is if I touch earth, but that buzzes my finger more than I'm comfortable with or feel is 100,% safe. Wouldn't work if it was DC without solid ground connection.
@@odoohub5010 You need very low current to light up the bulb in tester, even capacity of your body to ground is often enough.
Great video thanks - just ordered the non-contact pen from your description!
i threw that blue lap pen out last month as it failed after 2 years. i have another scheppach one it it was showing the cable was live and the lap one wasnt, even changed the batteries to see if that was the issue. I always try use 2 or 3 methods to test, not just 1 for this reason.
Yes sensible to use multiple methods. Thanks for watching!
Try a Fluke pen... built to be reliable and last
I had the same with a LAP pen. I’m going to shell out on a Fluke or Megger, as the only brands I trust.
I have both testers .thanks for sharing. I’ve often wondered how they work, so the body completes the circuit.They are handy .😊
Thanks for watching!
It seems to me that the author of the video is uncomfortable with the idea that he could be part of an electrical circuit. Many people have used these screwdrivers, but I have never heard of anyone getting electrocuted by them. However, I agree that they do not always correctly detect the absence of current and this can lead to a serious electric shock.
Blimey, I've been using these most of my life, since I was a kid. I'd just assumed if they were sold to perform the task, they'd be safe and suitable for doing so.
The risk is damage or water ingress. Thanks for watching!
A lot of unsafe shit is sold out there, it do not mean it is safe or right to use it.
@@TheDiligentDIYer1759 i think if you look at the numbers of people hurt or killed by them, they are probably safer to use than driving a car. the only thing hes saying there are even safer options out there
they ARE
1. Turn off the mains at the switch.
2. Take the fuse out of the fuse box.
3. Test if it is still live. Don't assume the circuit you are working on is wired to the correct fuse.
I removed about 16' of lead sheathed wire having crumbling rubber covered wires inside when decorating. I tested them with a multimeter to make sure they were dead before pulling them out. There's still more going into the attic.
What a BS, the resistor inside the probe effectively prevents shock. These probes are still very popular, since they are foolproof to operate, cheap and very safe. A multimeter requires a battery, the correct ramge setting and the cables need to be plugged into the correct sockets. In addition the cables and tips can be worn or damaged over time. What is worst, you have to use both hands, what I try to avoid when working with mains voltage. If sonething goes wrong there is a definite circuit through my body. While when working only with one hand and wearing shoes with rubber soles, I would hardly recognize even if i touch 240V directly with my fingers My safety rule: always keep a hand in my backpocket.
If your boots were fully insulating you from the ground, the screwdriver won’t light anyway….
If that were the case you would take your boots off.
@@TheDiligentDIYer1759 Ever heard of capacitative coupling?
That's why you should always test it on known mains before you start testing.
I have used them for years and never had a problem, however I have had countless multimeter leads go Intermittent which can be far mor dangerous.
Thank you. I was wondering if anyone was going to correct him@@ruben_balea
I've been using these since I was 15 and started to understand live/neutral difference. Never had a single, slightest issue with these. I always carry one on the jobs-I have that Kews meter, non touch pens and Stanley joist/cable sensor, but that pen is the simplest and fastest device.
Funny video saying the old tester is dangerous. Using it from 35 years never felt any danger. Any gadget when water goes in will be dangerous.
You mean Woolter?!🤣😂🤣😂
WHO IS WALTER
I have two with no problem for years , very useful with things that may or may not have current like fuse testing
Thanks for watching!
I have been using my Vitrex made in Britain one for fifty years with no problems what so ever, would I replace it with an unbranded cheap one I seriously doubt it, a very useful tool but I only give it the slightest touch certainly would not hold there for more than a second or two, it also has a piece you can take out and put a plug fuse in to test the fuse.
Thanks for watching
Have used them as a DIYer for over 40 years, even back when we did electrical work that is not allowed any more. Isolate at the board (in my case in the garage), lock the garage and put key safe, double checks on circuit, and above all don’t work on a live circuit. An early blown fuse after cutting o a live wire, and you learn very quickly what not to do. Non contact tester isn’t always reliable in my experience.
Thanks for watching
Few points to make on this one:
"dangerous" is relative.
Can you point to a single recorded incidence of an injury from a mains testing screwdriver? I can point to a large number of injuries caused by the incorrect use of a handheld multimeter (Which can fail to show the voltage if you have the setting on it wrong (ie wrong terminals or DC setting) and can actually cause an arc flash over if the wrong settings and terminals are used and which often can have damaged leads due to careless use onlow votlage systems and those leads result in electricution of the user.
Any "dual" probe tester also carries a risk as those probes can causes shorts in the EUT and necessarily makes those devices a double hand use, which means a current path more likely to cross the users heart
It's worth noting that the neon bulb used is actually enough to prevent a significant shock on it's own as its ionisation current is very low (hence its use) it is also very very robust and not easily damaged.
IME, the worst thing about mains testing screwdriver is actually the fact it IS a screwdriver, so people are tempted to use them for other things other than mains testing, often damaging the insulation on the shaft, which can leads to user shocks should the user hold the device below the handle
The no1 reduction in risk from "proving dead" is making sure you can get a positive identification of the high voltage potential before you attempt to isolate the circuit. IE if you isolate the circuit and use a mains testing device that does not have a proving unit (ie martindale tester etc) you never see a positive result that proves your testing is set up correctly and working as expected. So i always make sure i can measure and get a "live" result, then isolate and make sure i get a "dead" result.....
Sure, for commercial use you need a proper industry standard tester, but for DIY i'd much rather someone used a testing screwdriver (having proved they get a positive result first before isolation as mentioned) that just guessed....... ;-)
Thanks for sharing your opinion
Thanks for the video. It's good to make sure we are safe. I never use that tester again and as you have pointed out, I got myself both the better qualiter tester. Better to spend some money and be working safe.
The non-contact testers work on the electric field NOT the magnetic field. The magnetic field is a property of current flow yet these voltage testers work even when no current is flowing.
Thanks for watching
Exactly - capacitance coupling .
I believe I had the first of this type of tester and it worked fine. That was quite a while ago. Now I use an absolutely safe current tester I made myself to test outlets and detect the presences of wiring within walls.
Thanks for watching!
The on I had in the sixties was okay for indicating mains voltage, but worthless as a screwdriver. Too easily broken.
Thanks for watching
I prefer the screwdrivers with an LED, transistor and a couple of watch batteries, they are brighter and much more sensitive. It can be checked before every use by touching both the tip and cap with a finger, it can also be used for testing continuity of fuses and lamps.
Thanks for watching!
We are using this type of tiny tester since in very beginning so how it becomes dangerous. Also we have digital probe like pen tester. You bring new theory may be you are promoting your new tester.
Thanks for watching
I'm amazed they still exist. Sometime back I got one from Poundland that works like this, but can also work contactless by pointing the top towards whatever it is. Works really well too.
Thanks for watching!
Very common tool in eastern europe, for decades. Still very much used. Like any tool, needs to be used properly. Also bites if you happen to touch a grounded part while probing. Unfortunately new models seem to come with physically small resistor.
Thanks for watching!
If you had ever read any old electrician education materiel from eastern Europe you will know that this is not the right tool to use, the right tool is a tester like the one shown at 1:35 in a more bulky variant, but one thing is what people is taught, an other thing is what they do in reality, they sadly often reach out for the easy fix solution.
@@K2teknik. Do you remember how those old voltage testers with 2 probes worked in 50s-80s? They were passive, without batteries and LEDs. It was just coil with core on spring. Impedance of this coil was very low. So if you dropped one probe, you could get shocked easy. Screwdriver tester was in fact much safer. And there was no way to test just one wire if it is life without connecting second probe to good ground.
Thoroughly agree!
You'll aways get people saying they've used one for years and they're quite safe, however, these are often the people with the least knowledge of electricity and its dangers. They'll assume that if it doesn't light up, then the circuit is not live. Bet they don't first test it on a known live circuit to check its working ok, as you would always use a proving unit on a two prong tester before use.
I remember as a 12 year old pushing one into a metal clad socket in the school physics lab, shorting it to earth and creating a loud bang and flash. Needless to say, the physics teacher was not impressed, telling me "A little knowledge is a dangerous weapon", how right he was! stay safe!
Thanks for watching Pete!
Do you know how a neon bulb works? It is basically a filament-less bulb. Which means there is a break in the line.
It's been used for probably one century already and the risk is close to zero.
I'll tell you, it is much more dangerous to not have it when you need it
Neon conducts electricity, the bulb would need to blow to stop current passing through. In the scenarios I mentioned like water ingress, having neon bulb wouldn’t make any difference. Thanks for watching!
I use both. I like the simplicity of the screwdriver and trust it after many decades of use. It does no harm to double check using two different tools
Thanks for watching Jonathan!
I think these work based of the AC as well as the grounds. Because if you have thick rubber shoes on and isolated from ground would the light still turn on ?
For me touching the end with an insulated tool didn’t work, I don’t think it would work if you were fully insulated from the ground either. Thanks for watching!
Yes, it does. (I've done it on occasions.) Your body's capacitance is sufficient to light the bulb without you providing a return path.
@@TheDiligentDIYer1759 can you the contact pen with lipstick balm fat on your finger to reduce a potential shock from the pen or wont the pen work at all then?
I've used and continue to use all three items you've reviewed. I take your point but I think it's extreme to say the screwdriver type tester is very dangerous. Personally I prefer the non contact tester as it's so quick and accurate and detects current in cables without removing any sleeving to expose the copper cores. Also many non contact testers have an LED light so you can see into dark spaces where many consumer units are located. Mine also has a green laser pin point light. So, overall many benefits over the old style tester. Thanks for yor video.
Hi. I was interested in your saying the red probe on a multimeter should be put into the COM. I did a search and other sites say the black probe goes into the COM. So who is right?
I think you’re right and Im wrong, it won’t make much difference for checking live though. Thanks for watching!
@@TheDiligentDIYer1759 come on man. Please stop posting such things on the internet if you are beginner.
Saying the red probe goes to COM is the 13th stroke of the clock, it casts doubt on all the rest. And advising a multimeter is dubious, there are a lot of cheap ones about that are not properly approved for mains voltage. I can see the argument against neon screwdrivers but you have to keep risks in proportion. I would only use one as a backup check. And two probe testers can give the wrong answer in some situations like lighting circuits.
@@TheDiligentDIYer1759 dont think half-assing electrical instructions for views or clicks or subs is the way to go...you dont want dead subs right?
Definitely not this one, the BLACK probe goes to the common.
Yes, you are absolutely Right. When it comes to Safety, LEAVE NO DOUBTS. 👍🏻 All it takes is Once for fatal accidents to happen.
You are right, don’t have one neon in my toolbox but 3 all day long, and let me brake down the news for you . If you are dealing with soak in water tools at electrical installations and repairs you shouldn’t even exist in this world and trade. My opinion
Thanks for watching
The problem with non contact is that you can get a lot of false positive because of the cross talk in the wires if there's two out of phase and a neutral/ground
Thanks for watching!
This is very useful to know. I'm the most amateur of amateur DIYer and I've had one of these for at least 25 years and have never used it to test for current. The blade is obviously designed for the types of screws you find in electrical components and battery panels on toys etc so it's good to have around. As it's been rattling around my toolbox/kitchen drawer of doom for decades, there's a good chance that void had been bridged and I wouldn't have known to check. Thanks! By the way, can you use a multimeter to check if it's in working order?
You could put a multimeter with a probe attached to the top and bottom, then measure resistance. It should be very high or give no value at all, if it gives something low, then it’s dangerous to use. Still id just get a non contact tester to be safe. Thanks for watching!
You've be wise not to listen to this content provider
@@niv8880 What piece of information specifically is incorrect?
I always turn off the circuit when testing and then turn back on to verify tool is reading correctly. Final turn off verifies everything is safe to work on. I agree 100% that contactless is always the safer way to go.
Thanks for watching!
When I started work as an apprentice electrician in 1971 I had one of these. The charge hand took it off me and threw it in the bin. He then gave me a proper voltage tester. I have never used a screw driver type voltage tester since and never will. I have never understood why these have not been banned, especially with the amount of perfectly safe test gear that is available today.
Some of them are low-voltage (less than mains voltage), used to troubleshoot automobiles and other circuits.
Glad to hear it! Thanks for watching!
A neon tester will detect the hazardous condition where all available contacts have become live. The professional testers, multimeter or test lamp will declare the condition safe.
You sound easily influenced. "The charge hand" did a rampage and you abided. No explanations needed, no braining involved...
@u1zha Maybe, but In fifty years I never go thrown across the room because a "dead" circuit wasn't
I know of more than one electrician who couldn't say that after using one of those testers.
That only becomes dangerous if it gets submerged in water or in some cases if you where bare feet on a wet floor the problem with the touchless ones is they can only tell is there is power (which i already know there is) and not which wire is hot and neutral in order to wire the outlet correctly sometimes the wires are not color coded and even if they are i always check first.
Thanks for watching
while i agree that these should not be used for proving live/dead conductors, and for a quick indication a non contact tester will suffice. i use 1 for finding the live wire as normal sockets here dont have a defined live and neutral side. and for my old lathe to run in the right direction i need to know which is which ( and yes i'm setting up a cee socket so its always correctly hooked up later on havn't had the time and space to do so yet ). do you have any insights on how to cheaply identify the live conductor?
Difficult to know without seeing your exact situation, but a stop gap solution could be a cee to 3 pin converter, they’re pretty cheap and easy to come by. Thanks for watching!
@TheDiligentDIYer1759 yup thats exactly what iv been doing, and have labeled a few sockets with live an neutral side. But confirming whether the person before me actually followed color codes is always the gues. What affordable tool would you recommend for reliably differentiating live and neutral. My non contact isn't to clear about it and doesn't seem like a reliable way to me.
Where do you live that you have sockets without a defined live and neutral side. Here in the UK sockets always have defined live and neutral sides.
Nice cheap and simple tester👍
I'm a heating engineer. I have to say that I have been using 'neon screwdrivers' for 50 years (just about to retire) with zero problems. I worked with 45 other engineers...and I've never heard of anyone getting a shock from them. I don't like my 'voltstick', as I find that is unreliable, so is potentially dangerous to trust it. But the 'neon'...no issue.
Thanks for watching Barry!
best tool ever invented, I think this would be my number one choice always. I'm so used to it, I wouldn't even start changing a socket if I don't have it.
Thanks for watching!
Think you are all missing the point. They should be used as a probe, ie should have a pointed end. Most of them dont, they become flat head screwdrivers and levers by diyers, which are over stressed causing a crack in the shaft, especially cheapo models. Current could pass resistor into crack onto a sweaty hand and there lies the problem. Simples.
That’s a good point, I haven’t seen one with a pointed end at all, only screwdrivers. Thanks for watching!
i havent used one of those for years , im not a pro but have done a few houses in my time ( always have had my work checked by a pro) and i have never compromised on my safety equipment and a few years ago i got a Fluke 1AC II VoltAlert - Non-Contact Voltage Detector Pen which wasnt cheap and i trust it BUT if someone is buying one of these things please check its the right voltage range , i didnt even think about it when i bought it and luckily i bought the right one , it was only later that i found out that they do different ranges and if you get the wrong one then it can tell you its dead when in fact its hot , especiallythe cheaper versions may not be as described
love your videos
Very kind of you, thanks for watching!
Ah the British electrophobia
Been using for over forty years.
Never any problems.
Great, so if you lose your neutral but still have a live, your "professional" 2 pronged tester says it's "dead" while it's clearly NOT.
Stick to house bashing.
Thanks for sharing your opinion
Most approved voltage testers now will show a voltage if connected to a live wire without the 2nd prob on a neutral or earth
This is an awesome video! Thanks in particular for explaining the failure modes of the pen testers. I’ve always felt they were potentially dangerous, but wasn’t sure how they could fail exactly.
Also, you said two things about the NCVT that are slightly wrong. 1) They sense the electrostatic field, not the electromagnetic field. 2) They do in fact use your body as the return path, and if your boots are too insulating, as you said in another comment about the pen. But they will also fail to work if you’re too far away from the ground, like up on a ladder. I’ve been up on an 8-foot fiberglass ladder and found them to still work, but I’m not sure how much further I could get.
Thank you!! Thanks for watching!
@@TheDiligentDIYer1759 Any comments on my observations about the height above ground limitation on the NCVT? I haven’t been able to test the statements I’ve read on the issue and am wondering if you’ve heard anyone talk on the subject.
These should be banned
Why?
@@jumper233 best to use the right tools to check for voltage rather than toys, as electric is not something to play with. Approved voltage indicators etc. When working on 415v etc I wouldn't even imagine getting a toy to test for power. Not these old school DIY gadgets. Heard they have potential to shock but could be hearsay. VDE rated screwdrivers and approved rated voltage indicators. Decent multimeters etc. That's my opinion. Maybe I'm wrong🤔, what do you think
No doubt there will be moves to ban them. Depends on how used. I was wiring up a two way switched lighting circuit for disabled neighbour, so isolated what I thought was the relevant fuse channel. It wasn't possible to shut off supply at the distribution board, as neighbour felt cold. A 'shared neutral' error meant I could not do a DVM check. While working, the thing lit up, saving me from a shock. These should be for alert purposes only but not as a substitute for a multimeter, I would agree.
Thanks for watching!
I've never had any problems with those testers thru my 30y career. Neither with the cheap one nor with the certified one. I even made my own testers from spare parts, which had extended wires, for testing in two points 400V, or 230V (with a person as a neutral potential). The main thing to remember when working with these types of testers is that BEFORE you put the tester on the wire you are testing - FIRST touch any point that you know is live (to make sure the tester is working), and ONLY THAN touch that point you are examining.
I have been using these for 30 years and never let me down 😮
Thanks for watching
the stuff complete the circuit by grounding through your body. this is fine for casual electric work i.e. wiring your house power socket, checking the live/neutral for active current. as long as the current is not above kilovolt range, you're fine as the current passing through you is negligible.
I found the non-contact tester gave me a false positive when I changed a ceiling light pendant. It indicated that the wiring was live but in fact it was picking up some induced current. I had the MCB turned off. I checked with a neon type screwdriver similar to the one examined. I had previously checked it indicated live reliably when the MCB was turned on. I believe the MCB isolates only the live conductor and not the neutral.
Thanks for watching!
Testers are fine as long as you don't use them as screwdrivers! I forgot that I had broken it trying to unscrew a device I was trying to fix. Then days later trying to check an outlet, I got the shock of a lifetime. Thankfully the spring coil and other contact resistances still had enough impedance to reduce the current.
I have been using neon tester for ages and found it to be absolutely safe
Thank you very much for introduction of non body contact voltage tester,
We used to build something like this at school. It has a resistor for protection against electric shock. It's totally harmless.
Thanks for sharing your opinion
It's harmless if it is in it's original condition. The video showed potential fault possibilities which could render it dangerous. I think the possibility of moisture ingress was illuminating 🌩
As a retired signalling tech support engineer who used to calibrate test kit from meggers to flukes too live line testers.
Any meter , volt pen or other circuit tester
Unless calibrated at least annually on catibrated test machine any item that is supposed to give accurate readings or safe to touch test equipment will have the potential to be wrong.
Sure use a live line tester but for me on sockets for example plug in a lamp turn off at the consumer unit if the light goes out its a good bet the circuits dead .
Double check with your uncalibrated diy test probe and you can be fairly sure its got no power.
I prefer meters to probes but still have a good Fluke non contact one that picks up power by just touching the socket housing its ultra sensitive but not as cheap as the diy prode drivers at around
£25
Thanks for watching!
Non-contact testers are great and I have 3. However, if you value your Spouse and children, then definitely get a Mains Testing Screwdriver. They can do what non-contact cant. They can test screws of switch boxes and socket fittings.
For instance, when we moved into our new house, two separate mains light switches had the live connected to the screws on the switch housing. This had happened because the live was shorting locally to the metal casing behind, no Earth fitted. This would have been impossible to test with a non-contact type, as it would be swamped by voltage from cable. Of the thirty odd sockets and switches in our new house, only two had this problem, but it only needs one to ruin someone’s day.
I mean the argument that something can get inside is quiet pointles, the bottom part and top part are detachable and one of your basic responsibilities is to check your equipment before using it, you can open it up and clean. Second thing is that some of them do not contain spring alone but spring and fuse. The spring wire tho should burn and shouldnt allow you to receive full voltage by design. Another important thing is rating of the tool which needs to be checked as 230-250V in sockets is usually 9A or 16A, anything like 25A and more and the producer of the tester themselves do not recommend to use it.
Perhaps older versions can be taken apart, but all the new ones I’ve seen cannot. Thanks for watching
I've never seen this particular design.
The one I've used had an old long fuse in it, not a globe. It also had a wire, which inserted into where the button is on this one, to an earth clamp.
One thing the non-contact pens really excell at is testing those screw-in type fuses... And I do know the coloured tab in the visible end of the fuse should come off when it goes... But often they don't. And sometimes the fuse holder actually has a little hole where one can put a probe into. But then again, often there is no hole. I have heard that sometimes some people have actually even broken the glass on those things to stick a probe in.
But a contactless pen works just fine just by tapping the glass with it. I remember a few times there were just huge panels with row after row of fuses. And obviously they should have been properly marked and all, but like so many times, there were little to no markings and sometimes things have been changed and while there might be a label saying one thing, it might be just mislabeled at that point. While the contacless is not perfect by any measure, it did speed up diagnosing the problem quite a bit.
Now some people have pointed out potential issues with basically any type of tester... And yes, nothing is perfect. Personally I don't trust contacless, because they are notorious for giving plenty of false positives and negatives. So I consider them more of a diagnostic tool, that can help to identify potential issues.
And one another thing I could also point out is one day I was doing this basic "health" test on a C-128 PSU... After all CBM power bricks are known to fail in ways that would fry electronics. It literally took a while for me to find any trace of electrical power on the connector pins. But ultimately I was able to measure more than double voltage on DC-bus. The reason why I had trouble finding any voltage was likely due to contact surfaces not being entirely clean. And mind you, they did look like pretty clean just by looking at it. But to get good contact with the probes it required some scraping around to get past all the impurities that had accumulated on the surface. While that was about fairly low voltage DC, similar things can happen with grid level AC as well... If you wan't to be completely sure, you should be able to detect power on and only after that verify that the power was disconnected.
And when in doubt, turn off everything. When dealing with devices that are connected to a socket, pulling the plug out of the socket is simple and sure way to make sure it is not connected... But even when fully disconnected, one should remember that capacitors can potentially store lethal charge, and while usually devices that have capacitors have drain resistors for safety... But it is important to understand that should a drain resistor fail, literally the only symptom could be the fact that capacitors won't drain.
When dealing with potentially lethal things, one should never, under any circumstances just assume anything.
I allways say that one should treat any piece of circuit as if it was live, untill proven otherwise. And like I said allready, every kind of tester and detector comes with flaws. Contactless might give false results either way. And any tester that does rely on a probe contact, might be thrown off by poor contact. Just because you pressed the probe against something, does not guarantee good connection.
As for those screwdrivers... I would agree on that. While other types might potentially have their own faults, having something that is designed to use you as a part of a circuit, is in my humble opinion, just looking for trouble. Maybe one could use that as a "last line of defence". But would I recommend those as primary voltage detectors? Most certainly not.
And as for potential safety concerns on multimeters and voltage testers... It should be obvious that one should pay attention to their condition. If there is any sign of damage to the insulation, one should stop using them immediately.
I use those screwdriver/ tester things - many years. A more sophisticated version has red-orange AND green lights inside.
.
Interesting, thanks for watching!
To understand the circuit you have to become the circuit
Excellent!
I have been using these screwdriver testers for many years and never had a problem, I’ve also used the volt pen which sometimes did me a false reading.
Thanks for watching!
I've always wondered how they work and had one as a kid, but was clueless when seeing only one terminal, so didn't know how the circuit would be complete. This is very good publicity of stating the safer alternatives as you don't fully know the volts and amps. You don't know if the resister would blow or accept the current if too high. Imagine the dangers of it being 30A! It would feel unpleasant!
Thanks for watching
Household electricity does not exceed 220v, sometimes I use the back of my fingers to test. For batteries up to 9 volts i use my tongue.
I do a lot of switchroom maintenance and there is always a risk of multiple sources of electrical energy that can feed back into the LV switch gear (UPS or gen sets). If I find anyone testing for dead with one of those screwdrivers or a volt pen I remove them from site. The HV side I test and then issue a permit when proved safe to work on. The LV side a tester and proving unit must be used!
This one is actually a higher end model if you can say that😅 the even cheaper knock offs often have a cylindrycal carbon-like hard pressed little tablet instead of an actual resistor and the button can not be a button, but a rivet to contact the spring 😅
Interesting, that’s terrible! Thanks for watching!
You are mistaken in the principle of operation of the indicator screwdriver - the current does not go through the user to the ground, the user is a capacitor creating an oscillatory circuit. It is trivial to check - put on thick rubber shoes and the screwdriver will still work.