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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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4th Aug 2019, 10:50 am | #21 |
Nonode
Join Date: Dec 2012
Location: Stockport, Greater Manchester, UK.
Posts: 2,105
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Re: Neon Tester Screwdrivers
It's always good to hear the advice of professionals so I had a look at electricalsafetyfirst who seem to require either a two-terminal tester made for the purpose or if that's inconvenient a contactless tester.
I'm personally uncomfortable testing between two points with a probe in each hand, but unless there is a suitable terminal for a croc clip that's what you have to do. Worse, how does that work if say your earth circuit has become live? As Ian says, contactless testers tend to light up if you touch any metal. It makes better sense to have a contactless tester without a blade and I might be tempted next time I'm in Toolstation. I already have an NCV facility on my Uni-Trend UT210E AC/DC Mini Clamp Meter which works ok, the specs says it will detect mains voltage at 15mm from a conductor To me, a neon tester is the most trustworthy test if you can get someone else to open the breaker and you see the neon go out
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- Julian It's good here Last edited by Julesomega; 4th Aug 2019 at 10:56 am. Reason: Better image |
4th Aug 2019, 5:35 pm | #22 | |
Octode
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,604
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Re: Neon Tester Screwdrivers
Quote:
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Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW. |
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4th Aug 2019, 6:49 pm | #23 | |
Dekatron
Join Date: Dec 2007
Location: Haarlem, Netherlands
Posts: 4,199
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Re: Neon Tester Screwdrivers
Quote:
Testing for a live chassis is one of the best applications as long as you know what you're doing (always test both plug orientations and interprete unexpected results correctly). |
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4th Aug 2019, 7:36 pm | #24 | |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Neon Tester Screwdrivers
Quote:
Lawrence. |
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5th Aug 2019, 2:33 am | #25 |
Heptode
Join Date: Mar 2017
Location: Cedar Grove, Wisconsin, USA.
Posts: 823
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Re: Neon Tester Screwdrivers
I guess, in this country, we get a little careless because of our low mains voltage, but I got bit on 240 volts on my industrial electrician's job, derived from three phase mains. It'll stun you pretty good, especially when you when you have a good contact with earth.
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11th Sep 2019, 12:06 am | #26 |
Nonode
Join Date: Oct 2014
Location: West Midlands, UK.
Posts: 2,181
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Re: Neon Tester Screwdrivers
Use a suitable tester ? And then again ,are the leads in date/safe to use. A non screwdriver ( kept in top condition, chuck it id you doubt it's safety) is something I'd sooner trust. As with all go/no go tests, it's safety essential that the equipment is trusted. Why not test the suspect circuit in the on condition. Screwdriver indicates - switch off and test again. Scrwdriver does not indicate- find a known working circuit and test it. I far these days that the Elf ( as in Elf & safety) has addled folks brains and stopped folks thinking about how to be safe ,unless ther's a long list of safety regulations.
And yes- I was qualified and certified in my last employment to work on 650v circuits, although in my GPO/PO carer, I often workd with 1000v AC power feed on CEL and inside ( certified dead) up to 4.5KV submarine power feed terminals. |
16th Nov 2019, 1:56 am | #27 |
Heptode
Join Date: Oct 2005
Location: Olympia, Washington, USA.
Posts: 664
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Re: Neon Tester Screwdrivers
Here we use a "Wigger" sort of a solenoid type tester.
I will use a voltmeter, or a plug in unit that shows all wiring is correct by 3 glowing neon bulbs. If one fails to light then there is a wiring problem at the outlet. Mu old ham buddy was an electrician working for the state. He used to have to find circuits that ran all over and finding the right breaker, in an office full of people prevented him from turning off the mains breaker. He would just take a light switch and connect a power plug to it, Flipping the switch to "On" would short the hot to the neutral. He'd plug it in and flip the switch. BANG! the breaker would blow. Likely not the safest thing to do, especially if the breaker had fused, but it worked for him. Something I would not want to emulate. |
16th Nov 2019, 11:14 am | #28 |
Heptode
Join Date: May 2015
Location: Chatham, Kent, UK.
Posts: 964
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Re: Neon Tester Screwdrivers
Hi yesterday i was checking for a fault/conections to a live chasis Hallicrafters s38 radio this thing is lethal switch in the N wire ETC any way the neon lit on the chasis when off , deciding to double check it didnt light what was going on ?
the said new neon screwdriver had gone faulty. Only use for convience test on known live BE 4 and AFTER any test. Mick |
16th Nov 2019, 12:22 pm | #29 |
Heptode
Join Date: Mar 2010
Location: Eastham, Wirral, Merseyside, UK.
Posts: 788
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Re: Neon Tester Screwdrivers
HI Mick.
I don't know if you have seen this, as this radio is known as the Death Radio. You will need to follow this advice before any service attempt on the above. http://www.geojohn.org/Radios/MyRadios/Safety.html Take care and be carefull. Gezza123 |
16th Nov 2019, 2:40 pm | #30 |
Heptode
Join Date: May 2015
Location: Chatham, Kent, UK.
Posts: 964
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Re: Neon Tester Screwdrivers
Hi thanks for the warning. I do not like ac/dc sets but this said buy me i think i will use an isolating transformer 240 to 110 volt. To check this i an using my variac but only a matter of time will plug into 240v ? so a tx will prevent this its only low wattage i think 29w so said tx will not be that expensive. i will not use an auto tx. Thanks again for the warning Mick
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16th Nov 2019, 10:36 pm | #31 |
Nonode
Join Date: Oct 2014
Location: West Midlands, UK.
Posts: 2,181
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Re: Neon Tester Screwdrivers
There's two considerations here. Do you use a neon which only needs one hand at the end of a tester connected to what may/may not be a lethal supply. Or use a meter with both hands on either side ( and a path across the heart) overthe voltage .( unless you can secure one terminal to a neutral /earth voltage first) . I was indoctrinated into proving by my ancient uncle a time served electrician, who insisted on only one hand contact . BUT the problem with all test kit ( including the neon ) is lack of proving the tester on a known live circuit first.
me- I'm not an electrician, just a bloke who's worked on ,and been tested on high voltage working methods ( up to 650 v DISTRIBUTION) , up to 1000v Ac ( anyone remember CEL 6 ) and a few UK-other countries submarine cable systems of up to 4500 v. |
17th Nov 2019, 6:46 pm | #32 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,998
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Re: Neon Tester Screwdrivers
I'd not trust an old-fashioned neon-screwdriver over a modern 'detector pen' such as the Fluke 1AC-II
However one place an old neon-screwdriver _does_ have its uses is in detecting RF parasitic-oscillations in power-amplifiers: you can get a bit of an idea as to whether the oscillations are LF HF or VHF depending on the colour of the glow. [purple means you've probably got a VHF parasitic going on]. |
17th Nov 2019, 9:13 pm | #33 |
Nonode
Join Date: Dec 2012
Location: Stockport, Greater Manchester, UK.
Posts: 2,105
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Re: Neon Tester Screwdrivers
After my last post I bought a Fluke which were on offer from Toolstation at the time, and it is an absolutely fabulous bit of kit. It will even detect live metalwork within a plugtop or a pattress-mounted socket or lightswitch. It self-tests while you are using it until you switch it off and beeps to confirm it's ok. Live indication is visual and audible. It has auto-shutoff if you forget about it. The quoted sensitivity range is 200-1000V ac.
Non-contact means you can verify continuity of the live conductor in an appliance lead I see Toolstation have now added a couple of cheaper voltage detectors, and Bangood also have one, but I'd choose the Fluke if I lose mine
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17th Nov 2019, 10:35 pm | #34 | |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,713
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Re: Neon Tester Screwdrivers
Quote:
At least that Death Radio makes an attempt to isolate the metal case. This set however, well see for yourself! https://youtu.be/eib6GSYS4CQ?t=229
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19th Nov 2019, 5:56 pm | #35 |
Rest in Peace
Join Date: Mar 2011
Location: Basildon, Essex, UK.
Posts: 4,100
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Re: Neon Tester Screwdrivers
Julian,
I have to admit to being confused as to which, of your many neon testers you show in your first post, is the type to throw away. The important thing to remember is; always test the circuit first with power ON to prove the tester is working. Then Isolate the circuit and test again to prove it is off. Always mark the fuse panel to warn others that the circuit is being worked on and not to turn it on. Mike |
21st Nov 2019, 8:25 pm | #36 |
Nonode
Join Date: Jan 2010
Location: North Somerset, UK.
Posts: 2,129
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Re: Neon Tester Screwdrivers
Many "proper" electricians dislike neon screwdrivers, except perhaps for doing up screws, and many employers in electrical or related trades forbid the use of neon screwdrivers.
However we must not become too paranoid, neon screwdrivers are simple, reasonably safe and reasonably reliable and fine for DIY or similar activities. Any doubts about reliability may be answered by use of TWO neon screwdrivers, both of which have been proved to light on a known live source before the work. A great deal depends on the size and complexity of the equipment being worked on the degree of risk. Examples include; higher risk= high capacity industrial switchgear with a FLC of hundreds of amps and a prospective fault currents of tens of thousands of amps. Significant exposed metalwork that is live in use. Before working on that, I would want FIRSTLY to observe it being isolated, removal of fuses in the substation for example, or isolation and earthing of the 11Kv into the transformer. I would also observe that the power goes off ! Did the lights go out ? THEN I would test with an approved tester, probably more than one tester. Lower risk; replacing hall light switch for a neighbour. Turn off the main switch on the consumer unit and observe that the lights go out. Use a neon screwdriver on the switch terminals as a "second line of defence", though in practice on a simple domestic installation, turning off the main switch and observing the lights going out would probably be sufficient. Both the above are almost certainly the same voltage to earth, but have very different degrees of risk. |
26th Nov 2019, 4:52 pm | #37 | |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,535
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Re: Neon Tester Screwdrivers
Quote:
Restored correctly with the isolated ground bus genuinely isolated from the chassis / case and the RF grounding capacitor replaced by a suitable value Y-class part it will be safe enough on 120V mains. Maybe add a mains ground to the case just for added belt protection.
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2nd Dec 2019, 7:47 pm | #38 |
Hexode
Join Date: May 2015
Location: Northampton, Northants, UK.
Posts: 380
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Re: Neon Tester Screwdrivers
When I was sparking I hated neons and loved my voltstick. The primary issue for me with neons is they are passing a small current thru one's body and on more than one occasion got a significant tingle due to a short path to Earth (leaning the arm whose hand is holding the screwdriver on the metalwork of a suspended ceiling for instance). Not dangerous or even painful but very off-putting. Also I seem to have a rather low impedance (changing 8 foot fluorescent tubes always gave me a significant buzz which didn't seem to happen to colleagues).
I used my voltstick all the time, but not as a safety tester. As a non-contact tester a voltstick is so useful for many things. But since it can only prove a positive and not a negative, it was never a means to test if something was safe to touch. Well, most of the time, I risked it for speed sometimes y'know but wouldn't advise anyone to do that. A test lamp is better than a neon screwdriver, a multimeter is even better. Always of course tested before and after with a known live source. And then first touch with a glancing touch from the back of the hand. Alternatively use a junior member of staff to do the first touch. |
3rd Dec 2019, 5:53 pm | #39 |
Nonode
Join Date: Oct 2014
Location: West Midlands, UK.
Posts: 2,181
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Re: Neon Tester Screwdrivers
Playing devils advocate- it's horses for courses on the safety front.
Neon screw driver - small current through body. Test lamp -sometimes ( maybe a spark), on leg of the test circuit would ( presumably ) be clamped to earth to leave only one hand holding the live lead to be placed on the circuit under test. Similarly for the meter . But both the test lamp high side and the meter high side need to be tested for insulation (presumably more than once). In an ideal situation, where do you stop testing ? [tongue in cheek] Give the HSE bods a chance and we'll have a dedicated person in a fireproof suit with half inch thick rubber gloves and a large visor ,equipped with a long very well insulated shorting pole. ( OH ,another requirement for said person would be strong nerves).[/tongue in cheek] |
3rd Dec 2019, 7:27 pm | #40 |
Heptode
Join Date: Jan 2008
Location: Shrewsbury, Shropshire, UK.
Posts: 841
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Re: Neon Tester Screwdrivers
That's it, "Switch off, Isolate, Dump, & Earth"
Otherwise you'll be like the poor technician who returns to an H.V. installation, - from a dentist's appointment, only to find out too late that his colleague has reversed the connections of an inductor/capacitor circuit. Big bang! Anyone remember the BBC-2 colour test film, circa 1967/8? |