Multimeters for electrical installations

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  • Опубликовано: 31 окт 2024

Комментарии • 109

  • @parvezakhtar5512
    @parvezakhtar5512 2 года назад +4

    I am electrical and mechanical engineer, I find your videos covering such a wide ranging topics especially your delivery of information is jargon free, easily digestible and one can understand everything in its simple form, I would like to know how ,when and where did you learn to communicate so effectively with your audience, every video is informative, precisely executed, well done John and thank you for your service and the contribution you are making in sharing and passing on your knowledge to current and future generation of engineers to come, it is rare to. find engineers of your caliber. You are keeping the legacy of engineering excellence alive, I salute you for that. Shame one cannot purchase a DVD set on all the subjects that you have covered, I would be pleased to have the opportunity to watch them fo reference purpose as an engineer. All I can say is that the videos I have seen have been so captivating, informative, educational and above all a pleasure, please don’t stop posting these great videos, you may not realise that what a great service you are doing for our great nation.
    Thank you John , kind regards, parvez

  • @TheSteveGullick
    @TheSteveGullick 5 лет назад +11

    Possibly the most informative thing I have ever seen on the use of multimeters. Brilliant.

  • @Graza25
    @Graza25 3 года назад +1

    I love how you actually communicate with your audiance. Your addressing an audiance that has at least a basic knowledge which cuts out of time.
    Great vids.
    I'm a sparky myself, but i was sitting watching some of your vids out of curiosity and im certainly giving you a 10/10

  • @ollieb9875
    @ollieb9875 6 лет назад +4

    "A fairly unfortunate occurance" certainly is one way to describe the explosive detonation of a subpar multimeter. I love your humour. Thanks for making these videos. ❤☺️

  • @charlielittlefield717
    @charlielittlefield717 2 года назад +2

    I genuinely enjoy watching your videos JW. You always present them well, provide useful and informative information, and I enjoy your humour. I've learned so much from these, so Thank you.

  • @jasonbennett3718
    @jasonbennett3718 4 года назад

    The most detailed information I have ever seen or heard explained about a multimeter. Thank you for this explanation John, I applaud you sir 👏👏

  • @Equiluxe1
    @Equiluxe1 7 лет назад +10

    I often use the HZ facility on my Fluke meter when working on generators,previously I had to use a tachometer which can be awkward as guards need removing etc. with the HZ range I just plug the meter into the socket and test the voltage and frequency just by pressing a button. If your meter has a HZ symbol seperate from the voltage one dont use that on power as that is intended for things like speakers always use the one against the voltage range as that goes to higher voltages, found that out years ago when I blew a meter up on a large genset. Equally i find the capacitance range very useful when fault finding as alternators often have more than one on them and start doing strange things when the capacitor is out by a bit.

  • @Reuben1024
    @Reuben1024 7 лет назад +4

    A good overview John, agree regarding "transistor test" function, seems to impress so many novices. You did briefly mention probe Cat. compliance and guarding but surprised you did not spend a little longer on this (and GS 38 compliance) since you were dealing with multimeters for electrical installation. Many a time I have seen students damage the supplied probes with their good multimeter and then obtain some "bargain" ones from various online budget suppliers with the corresponding implications.

    • @shana_dmr
      @shana_dmr 7 лет назад

      Where do your students buy probes that badly insulated? Once I wanted to find a dodgy set of probes for demonstration purposes but even ones shipped with 5$ Chinesium brand multimeters survived 1 kV megger insulation testing easily, so it had to be some next level kind of shady budget supplier...

    • @seprishere
      @seprishere 7 лет назад

      I have a multimeter from B&Q which claims to be CAT III rated and which has a transistor test through an adapter that you plug into the mA and common sockets. I guess this isn't quite so bad.

  • @shemp308
    @shemp308 7 лет назад +3

    good video! wish I had seen this 30 years ago. I did just what you talked about! had my old meter smoked in my hand! NOT FUN. Lost a good meter had the **** scared out of me! learned my lesson and always put the leads back.

  • @milesbancroft
    @milesbancroft 7 лет назад +12

    Thanks John. It was an interesting and informative video. Especially with regard to the dangers associated with shorting out in the amps setting and the low impedance setting. However, am I alone in thinking of Ned Flanders when you kept repeating "nothing at all" ?

  • @neil2742
    @neil2742 6 лет назад +1

    Interesting article. One thing I will say, multimeters fall under the remit of IEC61010. One of the sub sections for that is for requirements for multimeters and it explicitly stated that meters must be rated CATIII as a minimum

  • @1000Zebedee
    @1000Zebedee 3 года назад +1

    I think you should work for the BBC John. I would love to hear your rendition of the shipping forecasts...'a fairly unfortunate occurrence might occur should you be foolish enough to sail through the storm conditions in your old bath tub'

  • @harukinzaphod
    @harukinzaphod 6 лет назад +1

    An excellent explanation on using multimeters. Great work John.

  • @felenov
    @felenov 4 года назад

    I have quite a few Fluke and Gossen Metrawatt multimeters. My personal favourite is the Fluke 87V.

  • @TheEulerID
    @TheEulerID 4 года назад +2

    My advice is always buy a multimeter with auto power-down. I've lost count of the number of times I've gone for the multi-meter and found the battery has died because I'd forgotten to turn it off. The meter I have now gives a warning beep after a period of time and then shuts down a minute or so after that.

  • @Nathan-ng1kp
    @Nathan-ng1kp 2 года назад

    damn, this dude is going hard on multimeters. Very helpful

  • @warrengray610
    @warrengray610 7 лет назад

    You have hit the nail on the head saying only basic functions are required, Electrics is largely focused on the presence or absence of power, on or off, electronics is more about manipulation of currents to perform for a range of functions,
    But weirdly digital electronics comes to resemble the on off nature of Electrics, is the light on is the light off, what are all the possible states?
    Fascinating

  • @guido7412
    @guido7412 4 года назад

    Really informative - like many of your other vids John - (your sarcasm is fantastic !)
    I start my Part P / 18th ed course early next year.. your videos are providing a sound basis for my studies

  • @tabletsam9505
    @tabletsam9505 4 года назад +1

    About "blowing in flames". It would go with a loud bang. Cheap Chinese stuff as well. My grandfather showed it to me on the multimeter from 50s. There was a button to reset the fuse. Later electronic multimeters will need a fuse changed manually

  • @peterjones3245
    @peterjones3245 6 лет назад +1

    Although like the rest of everyone on the planet I have a decent digital meter I still find a use for an analogue meter (yes - the ones with a scale and pointer!) I find these are actually more useful for "tracking" a changing voltage and/or current especially when the change is quite rapid. Admittedly more for my electronics work rather than electrical work

  • @eminem2
    @eminem2 4 года назад +1

    When I was fitting my Nest thermostat, the old thermostat wiring was using a Black, Brown, naked wiring (pre 2006), so the idiot in me, led by the instructions was wondering if I got a 2 or 3 wire switch, so I decided to test if the boiler would switch on by me connecting the brown and black with a multimeter set to 10A. Well, it worked, by now that I've seen this video, I'm glad I did it on a thermostat wire and not the mains, if I hadn't seen this video, I'd probably try it like the electrical ignoramus I am.

  • @tommyhanlon8012
    @tommyhanlon8012 7 лет назад +1

    Yet another good one J.W. Thanks. Clear & informative.

  • @CrazySparkie63
    @CrazySparkie63 7 лет назад +2

    Still have the same Beckman Industrial meter that I kept as a souvenir when I left British Telecom. (and still accurate ).

    • @CrazySparkie63
      @CrazySparkie63 7 лет назад

      The majority of my test equipment has to be sent away to be calibrated annually for the work that I do, so I test it alongside the calibrated test equipment on low energy circuits where there is no risk of power surges.

    • @acezone123
      @acezone123 7 лет назад

      CrazySparkie63 i got one too still in its leather box

  • @kevvywevvywoo
    @kevvywevvywoo 5 лет назад

    I discovered the difference between an electricians meter and my electronic one, a Fluke, when I dropped it from the top of a ladder onto a concrete garage floor while fault finding a garage door closer. I think the largest remnant was the size of a 10p coin.

  • @TurboTel68
    @TurboTel68 7 лет назад +3

    Hi John, perhaps you could do a destruction video of a cheap Chinese multimeter, maybe by giving a blast from a microwave oven transformer or similar? Cheers!

  • @davejones4740
    @davejones4740 7 лет назад +1

    Would moving the probes around mean that the the wires inside the insulator are rubbing together causing a resistance as there are so many strands moving. Plus the unit itself is giving electrical power down theses cables.

  • @PhilReynoldsLondonGeek
    @PhilReynoldsLondonGeek 7 лет назад

    Measuring frequency can be interesting when the power network operator have provided a generator to feed your supply during a failure on the HV side - it can be all over the place.

  • @davidhaines4173
    @davidhaines4173 7 лет назад

    You're a very bright chap J.W.
    No pun intended.

  • @areyouundoingthatorwhat9181
    @areyouundoingthatorwhat9181 3 года назад

    As an auto sparks you can become relatively familiar with the fuse in your meter/s,most automotive meters will take 10A,Although I do have a 20A meter I have connected my fluke(10A) to the occasional vehicle to look for a drain where the actual connection of the meter will 'wake' the vehicle and depending upon equipment fitted combined with the drain you see that 10A exceeded immediately and pop the QB fuse,either that or from forgetting while connected and inadvertantly turning the ignition on and/or triggering the starter circuit,they certainly don't like 700 amps! or most likely because of the reluctance to keep disconnecting and reconnecting due to the time you have to wait for the car to sleep after every connection before you get a true reading, you push your luck and at £16 a go for a fuse and now with leads either fried or you just can't trust at £30,it can be an expensive mistake,still cheaper than a cooking a £500 multimeter (with a million functions you never use👍😄) but it's getting close.

  • @J11DNO
    @J11DNO 7 лет назад

    one of the most useful videos I have come across, thanks!

  • @AlanLumsden
    @AlanLumsden 7 лет назад +1

    Can you do a review of Insulation testers John? It would be appreciated.

  • @Zooumberg
    @Zooumberg 7 лет назад +1

    Great video, it's taught me a lot.

  • @dudleyguy42
    @dudleyguy42 7 лет назад +6

    I remember working on a site back in the 1990's when a fellow electrician made the very mistake of leaving his multimeter set to current (amps) before placing the test probes across 400 amp busbars in an LV switch panel.....nasty business.....ambulance called for 2nd degree burns and skin grafts as I remember. Take care with electricity guys....it can bite you bad.

    • @shana_dmr
      @shana_dmr 7 лет назад

      That's why I'm fan of using mainly meters with no current ranges (or clamp meters, they usually measure current only via clamp) in such environments and having one meter with current buried deep in drawer/tool bag when you actually have to do current measurement by wire.

    • @Solocat1
      @Solocat1 5 лет назад

      That's why I always use Fluke for AC!

  • @davegibson2478
    @davegibson2478 5 лет назад

    Great video John, you can prevent the measuring of amps mistake by dropping a small amount of silicone on top of the A connector, call it a “Tip from the grave”.

  • @grotekleum
    @grotekleum 3 года назад

    Very informative, thanks for sharing.

  • @123tinhat123
    @123tinhat123 4 года назад

    Notice you used your fingers to hold the resistor and probes to measure resistance of the resistor. This is okay if the resistor is low but not okay if the resistor is high as it would just measure your bodies resistance. For example when measuring a ring circuit resistance you don't follow your example by grabbing hold of the test leads and then measuring the resistance.

  • @MrSJT
    @MrSJT 4 года назад

    Hi John, I noticed that measuring DC voltage on AC voltage settings and vice versa can give some funky readings, why is that?

  • @leonardbutcher8555
    @leonardbutcher8555 4 года назад

    Just wondered why you used the term $2 instead of £2 when talking meters with transistor testers on them when we are in the UK?

  • @alexdodd6768
    @alexdodd6768 3 года назад

    That bt multimeter is amazing

  • @david-ky7rt
    @david-ky7rt 7 лет назад +4

    Very interesting John. Thank you.

  • @warrengray610
    @warrengray610 7 лет назад

    Yep I agree your initial opening statement about some functions are never used, I know what the hfe measure is for example but I just use diode setting for finding base/emitter/collector on transistors as the method helps establish NPN or PNP types basic but works, watching the rest of your video on multimeters now.
    Cheers

  • @christopherjordan4812
    @christopherjordan4812 4 года назад

    John, did you work for EL and P at BT. Or even did you lecture at BT CTS

  • @56jmack
    @56jmack 7 лет назад

    another good video John.do you have any plans for doing videos on motors?

  • @andrewjb1981
    @andrewjb1981 7 лет назад

    keep up the good work jw .

  • @londontrada
    @londontrada 7 лет назад +1

    I have that exact same BT meter. Never seen the same one before

    • @ScottWayneJackson
      @ScottWayneJackson 5 лет назад +1

      Both stolen from BT?

    • @Martin64uk
      @Martin64uk 3 года назад

      They started issuing Robin ones without BT branding after these, quality kit and not traceable! 🤣

  • @animarkzero
    @animarkzero 7 лет назад

    Excellent Video!

  • @anonymusptbo8704
    @anonymusptbo8704 7 лет назад

    What does the yellow coding on the battery mean?

  • @johnburns4017
    @johnburns4017 4 года назад

    On the British Telecom meter. On the DC Amps section, it has 20m/10A (20m over 10A). What is that?

    • @jwflame
      @jwflame  4 года назад +1

      20mA when using the 'A' socket, 10A when using the '10A' socket.

    • @johnburns4017
      @johnburns4017 4 года назад

      @@jwflame
      thx, I thought it may be but was not sure. Obvious when you know. When you do not know, not very clear.
      So, when the lead is in the 10A socket the other settings in the amp segment range (2m, 20m, 200m, 2) do not matter? It is only 10A irrespective of where the knob is?

  • @IrishHitman79
    @IrishHitman79 7 лет назад

    Is the LoZ feature safe to use on 400v AC as it has a lower resistance across, For example checking a motor?

    • @jwflame
      @jwflame  7 лет назад +4

      Yes, the Fluke meter LoZ input isn't fixed - it starts with a low impedance but if full voltage is detected, the input impedance is automatically increased to avoid excessive current flowing. It can therefore be used safely up to the 600 volts rating of the meter.

    • @IrishHitman79
      @IrishHitman79 7 лет назад

      Thanks for the reply.

  • @B1cam
    @B1cam 7 лет назад

    Hi JW. Strange question.Iif the company you work for supply you with a cheap multimeter rated cat I working on 240v house mains supply. Do you think That one could send back /refuse to work with that piece of equipment based on safety??

    • @jwflame
      @jwflame  7 лет назад +1

      Yes - if your employer is providing tools or equipment, they must be suitable for the task. A Cat I meter is only for testing inside mains connected appliances and equipment, certainly not for building wiring, fuseboxes etc.

    • @B1cam
      @B1cam 7 лет назад

      thanks John

  • @-PaulT-
    @-PaulT- 7 лет назад

    Great video as usual.

  • @SteS
    @SteS 5 лет назад

    Can anyone recommend a good one for electronics or will a fluke do?

  • @warrengray610
    @warrengray610 7 лет назад

    Not strictly true, you can have inductive measuring clamp opening mains not required clamp=safety

  • @davejones4740
    @davejones4740 7 лет назад

    Great,after watching all your videos I can put into becoming an Electrician. Do you have any videos for doing y-plans and s-plans.

    • @jwflame
      @jwflame  7 лет назад +1

      Yes, all here: ruclips.net/p/PLVsHvs2Suqmr5HtxgbInR4bXmH0kLseWc

  • @GQLewis
    @GQLewis 2 года назад

    It would be great if this had chapter markers.

  • @zviratko
    @zviratko 7 лет назад

    You should have started with explanation of the various Class certifications meters have. In case someone watches this they could be sticking their leads in the mains socket within the first 10 minutes with no idea whether the meter they have in hand is safe for that use (and it most likely is not!).

    • @jusb1066
      @jusb1066 7 лет назад

      well even the lowest class I is suitable for mains domestic socket testing, the class type is actually a pain to describe, and really anyone who will be doing that kind of work wont need the information from John

    • @zviratko
      @zviratko 7 лет назад

      1) CATs on multimeters blatantly lie unless you have some brand-name equipment. Anyone who doesn't know what CATs are has a mutlimeter that lies, most likely.
      2) CAT II is not necessarily sufficient for mains, especially if you have a newer wiring that has much lower resistance.
      I think the ideal introduction to this video would be "Unless you know what CATs are without me telling you, NEVER stick a multimeter into a mains socket". Who needs to do that anyway? It's useful to have an indicator whether the wires are live, but there are better tools for that than a multimeter...

    • @jusb1066
      @jusb1066 7 лет назад

      yep i agree with you Jan, fully, then i can see why he didnt mention cats though! yes the cheaper meters are blatant lies, which is why everyone uses fluke who pretty much lead for safety even though we complain about their lack of features for the money. due to the high impedence it isnt the best method for testing mains (avaailability at least) and prefer the old 2 wire bulb tester as i was taught back in the day .

    • @thefiestaguy8831
      @thefiestaguy8831 7 лет назад

      Covered in a previous video of his......

  • @mavezy
    @mavezy 7 лет назад

    Great video!

  • @fijtips112
    @fijtips112 4 года назад

    Never understood the reason for the 700 AND the 200 since choosing either of these gives you the same number of digits. Also annoying that the UK is just over the 200V limit :-/

  • @MegaMetinMetin
    @MegaMetinMetin 7 лет назад

    Are flukes the industrial standard?

  • @budi0251
    @budi0251 4 года назад

    Those telecom multimeter looks good, quality parts inside there (ie. Those expensive caddock network resistors, 2 of them i think).
    Not even fluke got that.
    They use very common 7106 chipset 1999 count dmm chip, however a far cry compared to $3 free 1999 count made in china nowadays.

  • @timbaker577
    @timbaker577 3 года назад

    Very good as normal, not sure who the videos are for as I am a DIYer always being told get the qualified guys in don't do it yourself. Guessing if they are qualified they know this. But as I say very good as normal much better than trying to dryly read the operating manual of my cheap screw fix one.

  • @SnickersTS
    @SnickersTS 7 лет назад +1

    I have one of those chinese ebay mutimeters. Cost £1.75 including the PP3 battery and postage. It does not have any fuse at all internally. I would never use it on mains circuits again, but I can't anyway because the LCD module gives out faulty characters as I broke it by reverse polarity mistake :P .

    • @jusb1066
      @jusb1066 7 лет назад

      reverse polarity wouldnt break it, it reads + or - to the same level, its just junk

    • @SnickersTS
      @SnickersTS 7 лет назад +2

      No, I put the pp3 in reverse by mistake.

  • @markhodgson2348
    @markhodgson2348 4 года назад

    I'm very fond of my avo model 8 mk7

  • @eliotmansfield
    @eliotmansfield 7 лет назад

    The insides of that bt meter look similar to an early fluke dvm

    • @jusb1066
      @jusb1066 7 лет назад

      i actually wondered if beckman made that in the UK at all, it looks very similar to my made in taiwan dmm i bought in about 1988, then again, why wouldnt they copy a solid design!

  • @davejones4740
    @davejones4740 7 лет назад

    John what power supply cable size would I require for my power amps.
    Shown below is the diagram from the power amps manual. I have two power amps. I would want to have a separate power supply from the consumer unit.
    ZDamping Factor (static) ......................................... 1600
    Gain ...................................................................... 31dB
    Signal-to-noise Ratio .............................................. > 106dB @ full power
    Maximum Output Voltage ....................................... 60 Volts
    Slew Rate .............................................................. 70V/µs
    Maximum Current - Peak ........................................ 68 amperes
    Maximum Current - Continuous .............................. 32 amperes
    Crosstalk @ 1kHz ................................................... Not applicable
    Intermodulation Distortion ...................................... Unmeasureable
    THD (20Hz - 20kHz @ 1 watt) ................................ < 0.015 %
    THD (20Hz - 20kHz @ 500 watts) .......................... < 0.04 %
    Power Consumption @ idle ..................................... 40 Watts
    AC Power Requirements ......................................... 120V / 60Hz or 240V / 50Hz

  • @mikeray3993
    @mikeray3993 3 года назад

    230 V in the UK for the last 22 years, not 240

  • @johndavies4421
    @johndavies4421 7 лет назад

    1st class stuff

  • @Tangobaldy
    @Tangobaldy 7 лет назад +1

    6

  • @karoly365
    @karoly365 4 года назад

    Don’t disable auto captions please

    • @jwflame
      @jwflame  4 года назад

      Auto captions are generated by RUclips. I have no control over them.

  • @wattsupmike7593
    @wattsupmike7593 7 лет назад

    When measuring resistance not a good idea to hold the resistor with your fingers touching the probes as your body resistance will act as a shunt and give a false reading.

  • @grahamturner6119
    @grahamturner6119 3 года назад

    Buy a fluke ///the best

  • @emmetg888
    @emmetg888 4 года назад

    Flaming fireball. 😆

  • @robbs96
    @robbs96 7 лет назад +1

    42nd

  • @hunter00047
    @hunter00047 7 лет назад +1

    Naughty Naughty are you ex BT it's amazing what goes home with you when you leave. EX BT.

  • @kqfaht
    @kqfaht 7 лет назад

    Third. :P

  • @jo-anneflavel9361
    @jo-anneflavel9361 7 лет назад

    Second