Proving Dead - Mains Electricity

Proving that power is disconnected before working on electrical circuits.
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[@richardwilliams8953]

I love the deadpan delivery, could listen to you all day!

[@kevincuthbert5003]

Thank you for your clear and informative videos. I am a commercial Heating / Plumbing Engineer and have some dealings with electricity but am keen to expand my knowledge and find your videos very good. Thank you for sharing your vast knowledge.

[@hywelrees3667]

Thanks for being here. Incredibly useful videos. Glad I found you. Cheers!

[@georgewhiteford9869]

You probably just saved me from wasting money, but more importantly, saved my life! Excellent, very concise video. Thanks John.

[@davidlisney2059]

A very useful video, for work at Heathrow they actually specified which tester and proving unit must be used. I of course asked the question regarding using a multimeter. Your explanation was far better than theirs.

[@BabyRevealParty]

Great videos but lets cut to the chase here....when you going to play us a tune on the organ?

[@The944S2]

Classic !! :)

[@toadyw950]

Thanks JW for an excellent video. I’d like to make a couple of points… The Drummond test lamp you demonstrate was my favourite but is obsolete now. The latest models (MTL-10 or 20) look the same but use a tower of very bright LEDs to indicate voltage. They now works on RCD circuits without tripping them when measuring live to earth. Still my favourite for its robustness and clear indication. It’s very important to test all combinations of connection, L-N, L-E and N-E. I’ve investigated an accident in which a test L-N showed no volts but the electrician still got a nasty shock. A “borrowed neutral” raised the whole installation to live potential, despite the fully functional double pole isolator being “off”. To those commenters still saying to use a multimeter - I back JW 100% in saying this is dangerous - there are numerous subtle ways they can mislead or fail. I have investigated incidents in which multi-meters and non-contact volt-sticks failed to indicate live circuits and accidents occurred. In the UK the Health and Safety Executive [HSE] publish a guide “GS38 Electrical test equipment for use on low voltage electrical systems”. The HSE also recommend “Guidance on the management of electrical safety and safe isolation procedures for low voltage installations” from Electrical Safety First. Neither of these useful guides recommend multi-meters or volt-sticks for proving dead.

[@whp61]

Love your closing speech John, brilliant,

[@LukeStratton94]

Gotta love John's quality dry sense of humour!

[@POTTINGERMAN]

Me too love it

[@chrisgoes9610]

As a mech eng this looks perfect. Really greatfull for all the safety guidance too. I am that guy who will poke around and probably have the wrong lead / switch setting. Many thanks

[@davidhaines4173]

Thanks very much for the critical safety tips J.W.

[@kevincuthbert3058]

Great video, thank you for sharing your extensive knowledge.

[@Cumbriahandyman]

I am sure the electricians have their personal methods to test live/dead but your video is great for the DIY among us. Nice one.

[@AlanLumsden]

Good video JW. Keep em coming... There are only 2 recommended instruments to prove Not Live. One is the Drummond test lamp, with a double filament bulb, we've all heard the story about the single filament bulb. (ALWAYS TEST BEFORE AND AFTER with a proving unit). The other is a contact volt probe/tester, as opposed to a non-contact. Use both, ALWAYS!!! Locking off and posting warning notices is another story...

[@TerryClarkAccordioncrazy]

Point perfectly made with a bit of black humour at the end, love it.

[@ssjktjessica6]

Fair play john, dry as a crisp ,love the humour as much has the video's, brilliant 😂😂😂😂

[@sparked3113]

Very good safety video, excellent in fact. Here in NZ we refer to the 3 part process as Prove, Test, Prove.

[@tonycastro9997]

Well explained video. Thanks John.

[@TheChipmunk2008]

My favourite tester is the old solenoid tester I have, you don't need to see the thing, you can feel the 'hum' from it on AC, and it gives you a rough idea of voltage on the 'display' if you look at it, so you can tell the difference between 110, 240 and 415v supplies And good call on the people who will say they have had hundreds of shocks. It shows laxity if they have. The one you don't think will kill you is the one that will.

[@daveyboy174]

I still have my old solenoid style tester somewhere :)

[@tomlloyd9372]

Another issue with using a multimeter to prove dead is that even if you have the setting correct (voltage, AC, right range etc) - you may still have the your test lead plugged into the current terminal 'A' and you will now be putting a short across your circuit! If the circuit is live then hopefully the internal fuse in the device pops quickly And in the test lead probes (if they comply with GS38!) Using 500mA fused test leads when measuring voltage is a good idea. ..regarding the screwdriver, they are helpful for confirming correct polarity at PME cutouts... a test lamp/similar device will light/give you the right voltage values, but the cutout could still be reverse polarity!.. the screwdriver test will show if voltage is present on the combined neutral-earth, or not. Testascope is a sinilar product that serves this purpose. Or when testing a plug socket with a Bicotest Tru-pole. Cheers

[@westlondonrider3094]

thank you for explaining how the fluke work as an apprentice i have found this useful

[@twinpinesmall85]

Very informative and straightforward. Thanks.

[@deniswatfordsmart1049]

Brilliant straight talking and informative great stuff

[@paulmarrow6533]

Thanks for the valued advice.

[@tomroland2315]

A very interesting video. I use a Martindale tester, which was the approved device at work plus a proving unit. It's basic, fairly small, no frills but very reliable. Its capable for both AC and DC circuits. The proving unit is pocket sized so no excuse for not using it before and after a test. The voltage test screwdriver you showed doesn't work if you're wearing gloves and it's a candidate for the bin. We have access to Fluke multimeters which are not recognised as approved testers.

[@chrischeltenham]

I do love your videos, your like a teacher :)

[@SeriousSchitt]

17:00 You'll be hearing from their grieving widows John!

[@gallegalleson4427]

superb , brief and clear thank you son

[@beaufighter245]

Excellent advice and presentation, thank you. That Hammond looks in good order, are you a musician?

[@pa0sy]

Mr Ward, I’m very much enjoying your informational videos. They are the perfect companion to the City & Guilds courses. I have a question for you regarding safe isolation. In your video here, and in the labs at the college they only ever show safe isolation of the complete system i.e. testing at the load side of the isolator to ensure all circuits in the consumer unit are dead. Are you able to show how you would isolate an individual circuit, for example the lighting circuit, whilst leaving the other circuits live?

[@demonkey123]

The fundamental principal of electrical safety, is simplification, i.e. reduce the amount of possible failure paths. Use of a Multimeter to test for dead introduces the possibility of multiple failure paths as John explains in his video. However there is another aspect to testing that should be considered. The use of a combination of test instruments then reduces the possibility of a miss-test. I personally use a combination of both electronic and resistive test instruments when dead testing anything over 500v. It's just my own prerogative in the same way as I apply my own padlock on an isolation carried out by somebody else. Belt and braces.

[@donny9885]

Very informative and thorough. Thanks

[@gjbspark]

hi john, what do you think of the various test leads that have a self test (working ) function built in ? ( ie. push a button th check if function is ok )

[@copelandaa]

Good video JW, I have a cheap multimeter here (a present someone got me, I would never buy cheap multimeters myself) thats going spare I can send you so you can blow it up when you do your video on CAT ratings. I have all fluke meters anyway so it wouldnt be a loss.

[@Amirbaas]

Thank you Sir for sharing you though

[@ChrisTheSparky]

JW I'm up to 6 shocks, all could have been avoided. One shock was from a £5 tool fair multimeter where the leads had snapped under the insulation giving a false reading that the supply was de-energised.

[@derekrobinsonutube]

and there we have it :-)

[@balanelgabriel3516]

Hello John! I like electricity, especially transformers, 3 phase motors, but also I like to work with circuits. My question is : What type of multimeter can you recommand me? I am looking for a Fluke T-130, but I also like Fluke 113 and 114. Now I have a PeakTech 3340 which is working ok.

[@SomeGuyFromCrowd]

You didn't mention licking the live wire to check for voltage. Is that not standard practice?

[@MegaZsolti]

Pissing on it is better. You feel it more.

[@5084204]

I was 4 years old, and my Dad has shown me the way how to test 1.5V batteries. As an inquisitive child, I have extrapolated that knowledge and licked the live and neutral wires. It didn't hurt: I lost consciousness for about 3 minutes. No cardiac issues, etc Now I'm just using the extensors side of my limbs to check 230V - still no issues!

[@MegaZsolti]

@@mernok2001 Megkérdezem a Szent Pétertől.

[@johncosgrave9132]

Far better than licking in emergencies is touching the suspected item with the back of your fingers, with your fingers extended. The muscle contraction with any shock will pull your fingers, hand, and forearm away from contact. It is a useful technique for a quick check on steel enclosures, handles, etc. before opening them up. It's much more sensitive than a neon screwdriver.

[@itscoconutsaregood]

@@johncosgrave9132 I believe firefighters use a similar principle using the back of their hands when feeling through the smoke, in case there are live cables.

[@MrJohn1966elliott]

Thanks for understand. I'm from Western Aussie. about Safety and RCD

[@JoeRKsChannel]

John - could you do a video on DIN rail terminal blocks? I'm aware that there are types that 'bus' together and others that are electrically isolated. Thanks

[@allezvenga7617]

Thanks for your sharing 👍

[@dexwhitmore]

Nice vid JW although I didn't catch any reference to GS38 aside from the probe covers (with no mention of GS38) but I'll behappily corrected?

[@prime1971]

also always prove its dead yourself, never ever take someone's word for it, no matter how much you thrust them!

[@Naughty_Squad]

I remember when i was 14 my grangrandfather asked me to go to open the large metal box which had fuses for several houses and from there it goes to your house fuse board. Hi shouted to switch unplug the main line fuse which had 360v i had a long look and thought it was the right one and shouted back yep it's all good i think. Next thing hi gets a massive 360v shock and drops on the ground. I remember it so clearly there was a loud AAAAAAAA and a lot of swearing. Thankfully hi was okey just a bit dizzy. But i was blamed for it though i don't see it that way hi should have never even let me close to it .. There you go perfect example.

[@sbusweb]

What about considering the situations that external power has failed, giving false-positives on apparently disconnected power supplies?

[@AAAyyyGGG]

In a commercial situation the person doing thee job has to to a Risk Assessment. This would take into consideration things such as lack of external supply.

[@fotopunk123]

That's quite interesting! Thank you for explaining so much. I'm curious why the sound jumps sometimes when you touch the wire with the probing rods. Can you explain what's happening? This is not meant as a criticism I really want to know what's causing this, because I want to learn more about keeping audio clean my own work. It just seems weird to me that doing this can affect the sound of your camera because there should be no connection between the things, right?

[@jwflame]

Michael Hübner It will be capacitive / inductive effects, mostly being coupled into the wire for the microphone. Constant interference will be capacitive, and when connecting/disconnecting the probes inductive, as a small spark will be created at the probes - a similar effect when turning a switch on and off.

[@Jahmas88]

When you use that neon test driver, is it interfering with your microphone where you become part of the circuit? every time you touch it to the circuit, I can hear a faint buzz.

[@Bylga]

Thanks for sharing =)

[@bitTorrenter]

That's a really good Multimeter though. I have the 115 and typical of Fluke it's so robust. Easy to read display, easy to switch modes.

[@ORGPPL1]

I heard the Fluke proving units and others are not suited for use in domestic properties due to EMC. Is this true?

[@jeromewhelan6723]

Thanks for the educational video. I noticed that your use of the neon-light screwdriver produced 50 hertz buzz in the video's audio channel, both on brown AND blue. Have you powered that demonstration unit from a floating transformer secondary?

[@derekrobinsonutube]

Yes he did

[@azajakal9614]

great video thx

[@russellfreestone8580]

Very useful. I will treat myself to a proper tester.

[@ridefast0]

I have a chinese version of the multifunction voltage tester (UNI-T UT15) and it has an on-time limit of 30 seconds followed by a rest period of 10 minutes, presumably due to power dissipation in the input part of the device that covers the wide range of 12V to 690V. I wonder if the Fluke voltage tester you showed also has that test period limitation?

[@jwflame]

+ridefast0 Fluke specification has on time 30 seconds, recovery 240 seconds (4 minutes).

[@ridefast0]

Thanks - so it looks as if the heat is managed better in the Fluke. No surprises there.

[@inderjitdawoo7707]

Which brand is the best or most popular for testing equipment?

[@tamkaraoke]

GREAT VIDEOS JOHN HAVE YOU EVER HAD A SHOCK IF SO HOW MANY AND WHAT SITUATIONS

[@hugebartlett1884]

Those who didn't check first aren't saying anything any more!

[@jim.franklin]

John, pleased to see you discussed the use of a proving unit but it would have been helpful to mention that any test meter/indicators should be GS38 compliant - meaning that the test leads should be fused. I wonder who you aim your video's at because any qualified and suitably trained person would know how to use a Multimeter and know whether they had it on the correct setting or not.

[@pawestozek786]

I'd say that, if you don't know how to set multimeter up, you definitely shouldn't even think about doing anything, anywhere close to mains!!!

[@derekrobinsonutube]

and you would be wrong.

[@r.igormortis149]

One question: The test you showed only seems to prove that at least live or neutral are disconnected (in case of a partial failure of the RCD). Should one therefore not test live against a known and still connected earth or neutral too?

[@r.igormortis149]

+Shoppinguin It happened to me too. Since then I make sure to have a connected earth available (extension lead) whenever I do that. I only thought I had missed something.

[@derekrobinsonutube]

A test sequence should be more like Do a proving test on the measuring device test: L in ~ N out test: L out ~ N in Do a proving test on the measuring device

[@chrisgoes9610]

. I used to have an issued with an old Jaguar car draining healthy battery after 24 hours - any tips to fault find this type of problem?

[@db-bv5rs]

When testing at a socket for example. You should get 240v between live-neutral and live and earth. However should you get continuity between earth and neutral. And also when testing dead, should you get continuity between live and neutral, if appliances are still plugged in, but no continuity between earth and neutral?

[@e.powerdc1127]

Hi JW Can you please explain what happens at the pole transformer at the centre tap. I have ideas but need professional help with this one. I am a 69 years old student of the "Works of Nikola Tesla". .... Regards ..... DC

[@ericthekingthekingtheking4842]

Hi can you do a video on the sequence of tests r1 +r2 an loop impedance an the likes and why the tests are carried out thanks john

[@jwflame]

Roy Kirkham Yes, these are planned.

[@uranium_beaver]

I wish I could see this particular video before I did a costly mistake with first device you showed.

[@ShaunDobbie]

260v is quite high. We get 240 maximum where we are.

[@MiesvanderLippe]

Shaun Dobbie That's England for you. Certain (cheap/dumb) electronics have funky behavior as a result of this (stronger vacuums etc).

[@kickpublishing]

Depends how near you are to the sub station.

[@sparkie21]

I get 245-250VAC here most of the time

[@Adrianyoutubing]

260v is very high. I've never seen more than 250v. At my firm in the sticks, it sometimes gets as low as 200v much to the dismay of our governor. We are an electromagnetic Compliance company, on the low days we can only test to FCC and Japanese standards...

[@iandouglas451]

very helpful

[@matthewcummings9024]

After doing some DIY work over the years including 3 phase, one extra safety tip I do after checking the power is definitely off, is touch the wire with the back of your fingers. That way, if the wires were still live and all the muscles in your arm and hand contract, your arm/fingers will be pulled away from the live wires, instead of gripping it harder if you had used the inside of you hand.

[@MegaMetinMetin]

Depends what phase you touch🤣🤣

[@matthewcummings9024]

@@MegaMetinMetin Makes no difference. Your grip would still contract with any of the three phases.

[@jablot5054]

​@@matthewcummings9024or you could put your tongue on it!

[@matthewcummings9024]

@@jablot5054 Or worse! 😱🤣

[@ChristmasCrustacean1]

don't do that. 50ma is all it takes to kill you.

[@tutnallman]

And when the supply is off- make sure it is under your control! About 45 years ago i was examining a long extension lead that had failed- A man walked past the plug and an reasoned that the reason for failure was that it was not plugged in- so he did that- he then ran outside to investigate the screaming..... I was me connected - the man was my brother........... I often wonder.

[@richb313]

I can appreciate your approach but for me and the 45 years of experience I have working with electrical sources the only reliable method is the multi meter. I have seen way too many mis-wired mains and other supply boxes to in any way feel safe except by verifying it with a multi meter. I have also seen too many people take a shock because they only checked the terminals they expect voltage on. One time a tech actually cross wired 480 volts triple phase connecting the ground lead from the Control Van to one of the phases of 480 at the feed breaker. Let me tell you when he turned on the breaker it was quite the show. Never trust the color code, a person connected it, verify that the connections are according to code by testing it. Good quality multi meters and probes are rated for 600 VAC. When you need to measure higher voltages High Voltage Probes are used. I have regularly used this to check and test 3000 VAC circuits. The Multi Meter gives you the ability to make several different tests but it does require you to understand what you are doing. Any meter or test instrument can give you false or undefined readings if used improperly. I always told my guys to be smarter than the test equipment and tools they were using.

[@derekrobinsonutube]

You are talking about fault finding which is not the same thing. The two pole testers can also do continuity/resistive checks.

[@richardemery6690]

Proving dead should never be carried out with a multimeter, if in any doubt ask the HSE!

[@coffeecoffee5914]

richb313 this definitely seemed like a home gamer oriented video. Every maintenance tech/engineer I’ve ever worked with in the field has used a non contact power indicator followed by a multimeter/wiggy after testing on a know live circuit. Coil wiggys are handy for those phantom voltages from long wire runs, sometimes digital meters are too sensitive and give a reading of voltage but no amps behind it. The proving unit looks handy.

[@greywolf271]

If you don't understand the test instrument you're using you should'nt accept the result. DMMs have a high Z and can pick up radiated fields from surrounding wires. To this end, Fluke used to supply a high resistance parallel load to eliminate the ghosting. Most of the instruments shown are sufficient if you know understand the science. Unfortunately electricians are not engineers or electronics technicians.

[@cbcdesign001]

A voltage tester wont work across L-N with a neutral fault either. L-E with both sorts of tester would indicate the presence of a voltage however in some circuit configurations. The argument against multimeters is the potential for incorrect setting but that isnt a very strong argument either in my opinion because we have to use MFTs to do all sorts of live test work that also requires us to set the instrument to the correct setting. This procedure John Ward talks about is really aimed at the keeping the incompetent professionals (we all know one or two of those) safe, those people who make mistakes. Even a complete idiot can use a single function 2 pole tester and a proving device after all, its an idiot proof test.

[@twig3288]

I have an Di-Log DL114 auto ranging MM with a red light which is detects current on non contact basis or if one of the probes makes contact to a live conductor. It has a built in torch too. £28

[@derekrobinsonutube]

Watch carefully at 9:05 and you will see the Fluke tester does incorporate this.

[@networklink6305]

Hi John may I check with you still able to find the test bulb with the screwdriver set (able to trip) ? As you show on the video 5.58 thank you.

[@jwflame]

That one isn't made now, the nearest equivalent is this: martindale-electric.co.uk/drummond-mtl10-test-lamp-p-1715.html

[@networklink6305]

Hi John I think this one not able to trip the RCD ......... : (

[@jwflame]

Some of the Fluke testers like the T110/T130/T150 have the ability to trip the RCD , they have a switchable load function which will draw 30mA.

[@derekrobinsonutube]

Get a Fluke; they are the dogs dangly bits

[@MrChadwicj]

Hi John, Would you trust the LAP MS8922B AC/DC 2-POLE VOLTAGE TESTER from screwfix for 240v home use

[@jwflame]

I haven't used it, but it is made by a known test equipment manufacturer (Mastech), Screwfix have just had it relabelled for their own use. It's very basic but should be OK for voltage indication.

[@conaran7039]

How about plugging in a lamp and turning it on and seeing it go out?

[@stefantrethan]

Your demonstration did not in any way cover the possibility that neutral may be switched off but not the live wire. I only say this because you went into great detail about many unlikely issues, but this is actually a much more plausible problem which you completely failed to cover.

[@benhoward8241]

^ I have thought the same thing, I used to own a pair of digital testers like in the video and they will tell you if a dangerous voltage is on a conductor with only one probe touching, it didn't matter which one it was. It wouldn't tell you what the voltage was without a reference. Just out of interest one day i stuck one probe in a plug socket in the kitchen and the other on the steel casing of the dishwasher, 240v obviously. Take the probe off the dishwasher (one still in the socket) - red led (AC warning*beeping). One probe in socket and one in dry hand (boots on, tile floor) - nothing. One probe in socket, one in hand, bare feet, about 100v One probe in socket, wet finger on other probe and holding dishwasher, 240v. They are much more reliable than test lamps/proving units, which like you said might not prove anything if you don't prove it is live first

[@johncosgrave9132]

Yes, your preferred test methods only work if there is no neutral fault. This can be a significant risk in cowboy installations.

[@helltanner3722]

i had a active neutral supply reversal ..by the provider...did nasty things...was not happy when i found it...the provider was working in the street...they were seriously. embarrased.

[@alanesq1]

I was nearly killed once when I trusted a volt stick so I can confirm they are not suitable (I tested it on a known live wire and it lit up, tried it on one I thought I had disconnected - tried it several times) then cut the wire resulting in no more wire cutters ! Just wondering - if the RCD had developed a fault or was wired wrong and it was only switching the blue wire wouldn't the suggested technique in your video give a false safe indication?

[@derekrobinsonutube]

No

[@siratthebox]

I can hear the screwdriver.

[@waterpowerspaniels]

It's a sonic one

[@Solocat1]

That's not a screwdriver! Wow.

[@grotekleum]

me tooo buzzzz buzzzz

[@paulmarrow2851]

Self proving voltage and continuity testers, are they any good. Or is it best to get two separate units

[@jwflame]

A proving unit is still required, as it's necessary to create the 400+ volts to prove it with. Some have a built in function to test, but that's only for confirming the indicators on the device are working, that can't replace testing it on an actual 400+ volt supply.

[@MrSailbadthesinner]

Can I just add you need to test not just L-N but L-E and N-E as a faulty switch or RCD may break the circuit N but leave the L connected. Also 264v is above the maximum supply voltage you should be getting ESQCR specifies 230v +10% / -6% so 216v to 253v.

[@JohnDundee-el2ro]

Hi.can you explain a 3phase and neutral supply how is there not 3 neutral supplies when there is 3 100 A fuses I thought if 50A goes along the phase cable 50 A comes back through the neutral which would put 150A through the 1 neutral overload it I am talking about using the 3 fuses for 240 v systems can you tell me how this works and does not overload the 1 neutral. Cheers

[@jwflame]

If only one phase is loaded, neutral current will be the same as that phase. If more than one phase is loaded the neutral current will be less, and if all 3 have the same load connected neutral current is zero. The three phases are not the same, each is phase shifted by 120 degrees, so that when one is at the peak AC voltage, one of the others will be at zero. Current flows from one phase to another, and the neutral just handles any imbalance. More extensive description here: en.wikipedia.org/wiki/Three-phase_electric_power

[@grotekleum]

You can hear those probes when they make contact, must give out quite a pulse.

[@godfreypoon5148]

When I was an apprentice, they told me "To prove him dead, you must cut off his head". That was some time before I changed careers and got into the electrics.

[@magaphoto]

...aaand even *AFTER* all that excellent advice, if your're going to work on two bare wires for a ceiling fixture, touch both conductors together with one hand BEFORE reaching with the other. If you have done what is aptly described here, it should be a simple final check before potentially sending a deadly current through your heart. Worst case scenario, you burn a hole in one hand instead, while you scratch your head with the other, wondering how the hell did that happen.

[@db-bv5rs]

When using voltage probe testers, does it matter which terminal you put the needle in. If so, what terminals does the positive and negative go into? What would happen if you did it the wrong way? And also if I wanted to test a socket through the pins, where would I put the needles?

[@jwflame]

AC doesn't have positive or negative, and it doesn't matter which way round the probes are connected.

[@db-bv5rs]

@@jwflame oh I see thank you

[@m101ist]

@@jwflame but you have live and neutral. 🙄 Polarity.

[@Martin120577]

In the Netherlands appliances for proving 'dead' mains have to comply with NEN-EN-IEC 61243-3 or equal ( According to NEN 3140: 2015 6.2.3.101 ). A multimeter is not produced according to this standard and is therefor not suitable to use it that way. The procedure for proving 'dead mains ( 3 fase and neutral and PE )is as follows: -Be sure the tester works -test L1-PE , L2-PE,L3-PE,N-PE L1-N, L2-N,L3-N, L1--L2 ,L1-L3 ,L2-L3 and finally the last test for assuring the tester is still in working order. for a 230V it would go as follows -Be sure the tester works test L-PE, N-PE,L-N and finally the last test for assuring the tester is still in working order. I wonder if there are different sets of rules for proving dead mains between countries?

[@azajakal9614]

Always the best

[@davidmanning5874]

I MUST SAY I HAVE NEVER HAD ANY TROUBLE WHILE USING MY DURITE 0-798-50 CAT 2 TESTED IT AGAINST MY OLD AVO7 RESULTS OF WHICH ARE VERY VERY CLOSE I GET ON VERY WELL WITH EITHER OF THEM

[@calumr2051]

I get concerned by the number of people saying, "i have had lots of shocks and feel fine", "or 240v or 110v doesn't hurt that much, stop being a wuss" what is all the fuss about?" ect, They completely miss the point, it only takes their body resistance to be low enough to cause a fatal shock, which is only milliamps, why do you think an rcd is designed to trip as low as 30ma? The mains supply in your house is more than enough to kill you, whether its 240v in the uk, or 110v in america, they are both enough to kill, your body resistance determines the shock level of it being a slight tickle or nip to meeting your maker (in other words DEAD!!!) Electrocuted! and of course as you say john we won't be hearing from them.

[@malcolmcroll]

John am i wrong here - a/c v == 240 , you did a test for live & it showed 261 v , how thats ?

[@bunston1000]

The test prods in the digital voltage meter, should also be appropriately fused.

[@ianbelletti6241]

I am an electrician by trade. Multimeters are the most reliable tool for verifying power. They also tell you what your voltage is so that you know that the power coming in is in the correct range. If you're worried about having to set ranges or accidently going to manual ranging, buy a multimeter that has no manual ranging function. If you are worried about having to change lead positions and possibly getting it wrong, buy a multimeter with hardwired leads. Your best bet in the long run is to learn how to properly use a multimeter. Hot sticks (proximity testers) are considered the next level of reliability but have low end detection ranges (usually 24 or 50 volts), but do not tell you how much power is on the line. I have seen hot sticks detect induced power on a line because the induced voltage is enough for the hot stick to detect. Voltage detectors that use indicator lights have the flaw that you can blow out the lamp by over voltage, and that under voltage gives you a no power indication. If you want to be absolutely sure that you have no power, your most reliable choice is the multimeter. Of course, with all these pieces of equipment you should always verify proper working condition before usage, which includes checking operation on a known live power source within the operating range of the tester. Be aware of the category rating of your meter when you purchase it. It is part of the safety rating of the test equipment and has to do with how much protection is between you and the unprotected power source (power lines). faculty.riohondo.edu/jfrala/fluke_multimeters_-_abcs_of_multimeter_safety_multimeter_safety_and_you_application_note.pdf

[@ianbelletti6241]

***** That doesn't eliminate the fact that a good multimeter is by far your most reliable test device for power. However, the rule of thumb that anyone who works regularly with electricity is that when working around live circuits, treat the wires as if they have power on them even when you have verified that the power is off. If you were to have a combination of tools to verify power, both proximity tester and multimeter should be used in tandem for power verification.

[@FoodOnCrack]

+Ian Belletti i prefer voltage/continuity testers. They usually have a higher safety class and most of them have single pole indication where as a multimeter often doesn't.

[@ianbelletti6241]

FoodOnCrack The multimeters I use do both voltage and continuity tests. The rating of the meter as far as voltage range and category location are what give you the safety of the meter when it comes to available fault current. Your safety as far as verifying power comes in knowing how to properly use your tools. Proximity testers handle your single pole situations when the return path is broken, however, multimeters are still undefeated as far as power verification ability. Both have their shortcomings, but using both multimeter and proximity tester will give you the best warning as to the possibility of shock on the circuit. Of course it's recommended that you verify that your test equipment is working on a known live circuit prior to testing the circuit in question, especially the proximity tester.

[@FoodOnCrack]

that is why i prefer voltage/continuity testers. They have single pole indication, so it basically is the same as a neon screwdriver; you don't need neutral or ground for it to light up.

[@frankjohnson7204]

Hi Ian. Ensuring that a circuit is dead before working on it is the most critical test that you can do. For this, you need the instrument that you can trust has the highest reliability. This is always the "approved voltage detector". Testing if a supply is present, yes the multimeter but these are very high impedance devices and can give readings due to inductive or capacitive coupling from nearby live circuits and raise doubt if that circuit really is dead.

[@creativejamieplays7185]

If in doubt, big clive finger test.

[@l4d2160]

This info would be handy for working on automobiles, I think. Also, a topic suggestion for a future video. Why does the US (where I live) only use 120 volts when apparently everywhere else uses 240 volts? I do hope you eventually cover something like this. Would be interesting to see.

[@SeriousSchitt]

+Bryan Young That's quite interesting. A mate told me his take on it, and that is, Americans were first to receive electricity and it came in the form of 110 volts. Since then other countries had got it and realised that the 230 - 240 volt system was a heap better (more power I suppose) however Americans already had the 110 volt too well established into their infrastructure that it wouldn't be viable changing! A theory that would need proven, however, no doubt interesting all the same!

[@l4d2160]

From what I understand, we have 240 pumped into our houses, though it gets chopped into 120 somewhere along the lines. Like our stoves, washers and dryers all use 240, of course with a different plug so you can't screw it up and plug in a nightlight there.

[@JohnDoe-qx3zs]

+Bryan Young You are getting 220V/60 Hz phase to phase with a neutral in the middle providing two 110V/60Hz circuits (two phase 180 degree system). Most of the world gets 3 phases with 380V/50Hz phase to phase and a neutral at the star point providing 3 x 220V/50 Hz circuits. Britain and its colonies used to get 415V/50Hz and 3x240V/50Hz. So before brexit, the EU compromise was to label it all as 400V/50Hz and 3x230V/50Hz. Not sure if that will be rolled back after Brexit.

[@olahansen]

How to you test the provning unit?

[@declanmahon1969]

what happens if you put the probes the wrong way around? so in the video you were putting the black com cable probe onto the neutral & the red on live to get 261, but what if you did not know which cable was which or a cowboy job meant that you actually put the black com onto live & the red onto neutral... what would happen then?

[@fredbloggs8034]

It's AC. You would still get the same voltage reading.

[@mongolorigin201]

Which one of these 2 Fluke tester T5-1000 vs T6-1000 would pick John and why?

[@jwflame]

Depends on what functions you need, the two are not directly comparable.

[@mongolorigin201]

@@jwflame I m one of those new wanna be Spark( only 3 years in the trade even though spend 5k at college , but they thought us how to pass the exam) So I dont have much knowledge of any tester as I have'nt done any live testing to this date. Shall we say for profisional in domestic use to make it easier and have more function if needed in case they might come handy !. Thanks for your help.

[@dondenter]

John I noticed that your Fluke was reading 263 volts. I have been left the UK now for 12 years but before I left the voltage was 240 volts. Then the decision was made to make the UK the same as the EU continent at 230 volts. There was a tolerance though of I believe 6% so it allowed the UK to still operate at 240 because it was covered in range by that 6%. But 263 is out of that range isn't it?

[@jwflame]

263 is far too high, the limit is 253 (+10%). The test setup in the video was supplied from an isolating transformer, which has a higher than normal output voltage with no load connected.

[@dondenter]

OK on that John. That explains the 263 volts shown on the Fluke.

[@richmondoppong5585]

John Ward I don't understand at times when you test neutral you can see that there is a current flowing through.

[@MT-rc7mv]

JW....I have a question about the Drummonds,

[@ijazhussain7127]

Thanks for your great efforts.Very nice and useful videos .IJAZ HUSSAIN

[@jamescody1985]

Do you want to sell your vase? if so, how much thanks

[@zaprodk]

What kind of microphone-system do you use? I find it peculiar that it's so sensitive to anything electrical you do.

[@jwflame]

***** Microphone is a Speedlink SPES. Seems to pick up all kinds of interference which is amplified by the camera. It also means I can't use the camera with the mains charger connected, as the interference obliterates all sound (yet it's totally fine with the built in microphone).

[@zaprodk]

***** Try putting a bunch of clip-on-ferrites on the wires of your equipment. I'm sure it can be fixed.

[@kitcat6053]

Good technique to help the camera to focus at the end.🙂