Fluke T6-600 Part 3, VFD Drives and Other Waveform Testing

Ғылым және технология

Just a quick update on the T6. I received this comment a while back:
"The other problem with the non-contact voltage measurement of the T6, is that it is referencing to earth. When ever I am fault finding in a panel, I am testing phase to phase or phase to neutral as that is the working circuit. Testing phase to earth is poor measuring technique, and is predominantly done when testing of absence of voltage, which the T6 is unsuitable for. "
It made no sense to me that the meter would not work using the non-contact mode when reference to something other than the earth ground. So I tried it on a few 3P circuits using a one phase for a reference and the non-contact on the others and as expected, saw no problem at all using it this way. Obviously you would have to have failed your studies if you were to touch the button and grab a live phase with your other hand. I am using the black reference probe when doing these tests.
I also had access to another Mitsubishi VFD that I tried it on. The VFD was running a motor. No matter what I tried, I could not get the T6 to read the voltage. This controller was running with a carrier at 5KHz. The VFD was reprogrammed to 15KHz and the T6 worked fine. We tried a few other lower frequencies and was unable to get the T6 to read.
All of the testing I had done up till now with VFDs was at higher frequencies. Leakage current may be a problem and I would assume many controllers will run low carriers. My guess is the T6's non-contact feature will have problems with this.
The data for the meters I have tested may be found here: docs.google.com/spreadsheets/...
Answers to Frequently Asked Questions may be found here: docs.google.com/document/d/1g...

Пікірлер: 34

  • @1pcfred
    @1pcfred6 жыл бұрын

    Official Fluke cork accessory is a must have.

  • @Universal_Craftsman

    @Universal_Craftsman

    Жыл бұрын

    He had an aftermarket one, original Fluke cork with Cat IV rating is probably 200$. 😄

  • @joshpeck2697
    @joshpeck26974 жыл бұрын

    Thanks a lot for your time and effort. Bought that tester last month ,one thing for sure that field senser is not safe at all was testing hot wires in fast sequence around 9th was getting indication not energised . Bye the way perfect presentation. We all should buy you new tester .thanks a lot Merry Christmas and Happy new year

  • @joesmith-je3tq

    @joesmith-je3tq

    4 жыл бұрын

    I spent the time looking over the patents I could find on the technology. It is pretty interesting but as we have seen, it needs work. I doubt electricians would use it to prove if a circuit is live or not, but again I am not big on safety and assume people working in hazardous environments have proper education, training, license .... If you watched the ave videos, obviously it is not fool proof.

  • @scabthecat

    @scabthecat

    3 жыл бұрын

    @@joesmith-je3tq Certainly don't use it to prove dead

  • @joesmith-je3tq

    @joesmith-je3tq

    3 жыл бұрын

    @@scabthecat I doubt any electrician would.

  • @hi-friaudioman
    @hi-friaudioman6 жыл бұрын

    Man, those were some funky waveforms!

  • @jamessouth4776
    @jamessouth47766 жыл бұрын

    Nice video Joe,very interesting, seems like one of those is kinda an initial test to get some rough measurements on some equipment before you would grab a normal industrial multimeter, I think still would double check its readings!

  • @joesmith-je3tq

    @joesmith-je3tq

    6 жыл бұрын

    I guess if you knew ahead that the T6 was compatible with the waveform you wanted to measure you would be fine. In general, from the limited tests I have ran, it would be fine in many cases but it's not good enough.

  • @NiHaoMike64
    @NiHaoMike646 жыл бұрын

    Could it be that it reacts adversely to frequencies higher than what the VFD puts out? Perhaps it's worth trying to use the noncontact feature within a foot or so of an operating ignition system? Could be a real problem for HVAC techs who regularly deal with modern gas furnaces.

  • @felixcat4346
    @felixcat43466 жыл бұрын

    Thanks for doing all these tests. It would be very educational if you could try doing robustness tests on a few automotive battery operated oscilloscopes.

  • @joesmith-je3tq

    @joesmith-je3tq

    6 жыл бұрын

    I can't imagine taking a $4000 Fluke scope to task. Like any scope, I doubt their front ends are designed to survive transients like these. This is why I use various high voltage probes with the the scopes. I did test a low end 100X probe once which is why I started to make my own. The scopes cost too much to put them at risk with a poor quality probe.

  • @wktodd
    @wktodd6 жыл бұрын

    Nice one Joe:-) Looks like the meter is safe enough except for the false negative on spiked waveforms. I didn't catch, on the first viewing, whether the meter differentiated between no volts and no read, is it obvious that it is not reading rather than no signal?

  • @joesmith-je3tq

    @joesmith-je3tq

    6 жыл бұрын

    The way it works, you can wrap the black lead through the clamp and the lack of ground indicator will turn off. So they will show you when the circuit is complete. When the meter is not connected, you will see lack of ground active and three dashes. If you watch the video, often you will see the three dashes with the ground indicator off. Again, the same case as just testing with the black lead in the clamp.

  • @RGSABloke
    @RGSABloke5 жыл бұрын

    Awesome video sir, I hope AvE had a look at this too! He also had concerns about it. I am not sure this meter is directed at, seems to me the marketing wanks have been given free hand here. I would jut get the 381 it works just fine. kindest regards JOE

  • @MK-sy5lp
    @MK-sy5lp10 ай бұрын

    Hi joe Sorry very late to the party with a comment 😂. Thank you for yr awesome videos highly appreciated Would love to see how all yr meters read that output voltage from the drive Tested my 867s brymen it reads about 6v higher than my fluke 87v on a small drive with frequency of about 1.5khz Regards

  • @joesmith-je3tq

    @joesmith-je3tq

    10 ай бұрын

    What's the 3dB rolloff for your Fluke vs Brymen?

  • @MK-sy5lp

    @MK-sy5lp

    10 ай бұрын

    @joesmith-je3tq to be very honest I have no clue Not very technical when it comes to that

  • @MalagasOnFire
    @MalagasOnFire6 жыл бұрын

    We have in PT a lot of cork. Well the clamp doesn't like much noise / glitches on the sinewave and i think in the part 2 there was a refered 2.4KHz frequency carrier on the clamp and in part 3 the final pure sinewave was tested at 2.399ish KHz, which is very near and would trip the meter and does not read even at 10% of the value. On the other hand if the device is not reading properly we could also suspect the line by its behavior... Very nice test JIG and wave form generation. What about doing a reading between two Power Line Ethernet points , will it trip either?

  • @joesmith-je3tq

    @joesmith-je3tq

    6 жыл бұрын

    Are you asking about those adapters that allow Ethernet over AC lines?

  • @MalagasOnFire

    @MalagasOnFire

    6 жыл бұрын

    Yes, that kind of adapters

  • @joesmith-je3tq

    @joesmith-je3tq

    6 жыл бұрын

    I assume you are required to have a licensed electrician install these which is why you are asking. I am not understanding your question "will it trip either?" Ethernet should be isolated and I doubt they have two of these sitting next to one another. So I am not sure how you are proposing you would connect the T6. Could you just post a quick sketch and post it on the EEVBLOG site? This may help.

  • @MalagasOnFire

    @MalagasOnFire

    6 жыл бұрын

    My question is if the T6 clamp meter will stop reading voltage of one of the AC terminals in between these power line ethernet that you plug on the wall socket one end and then another, assuming that it introduces some sort of high frequency signal on the AC line between the two power ethernet's . Here is the sketch : photos.app.goo.gl/B0qr0wkNsptsawkN2

  • @joesmith-je3tq

    @joesmith-je3tq

    6 жыл бұрын

    We already know there are cases where the meter will not detect voltage. I don't own any of these adapters but you may want to try some of the other reviewers. Perhaps they are using these.

  • @mattperttula5210
    @mattperttula52103 жыл бұрын

    I've been playing around with my fluke T6 and an oscilloscope. If you connect the ground of the scope to the negative test lead and hold tip of the scope probe in the fork with Field Sense active, the device emits a 2.4kHz sine wave that the scope can pick up. You actually don't need to ground the scope to the meter to see this, that is just when I got the best signal. As soon as you turn off the field sense function the 2.4kHz waveform disappears. If you look at the waveform that the meter couldn't read around 8:26 and count the peaks there are 26 peaks in 1/4 cycle so the frequency of the waveform superimposed on the 60Hz sine wave is 60*26*2 = 3.120kHz which is pretty close to 2.4kHz. Without fully understanding what they are doing on the inside, it appears that they are modulating the Field Sense measurement on a 2.4kHz carrier frequency. My guess is that if the signal you are measuring has too much frequency content in the vicinity of 2.4kHz the meter can't deal with it properly. it would be interesting to see the frequency spectrum for the wave forms that fail to produce a reading. Thanks for the informative video!

  • @joesmith-je3tq

    @joesmith-je3tq

    3 жыл бұрын

    You may be interested in the following: www.eevblog.com/forum/testgear/fluke-fieldsense-contactless-voltmeter/

  • @mattperttula5210

    @mattperttula5210

    3 жыл бұрын

    @@joesmith-je3tq Thanks, I'll check that out. Really enjoy the videos, super useful information.

  • @MarcusMussawar
    @MarcusMussawar4 жыл бұрын

    when would you see waveforms with the small spike in the field? what is something that could cause those ?

  • @joesmith-je3tq

    @joesmith-je3tq

    4 жыл бұрын

    I am not sure what you consider a small spike. The act of sitting in a chair can create small spikes which I am sure is not what you are asking. I suggest doing some searching using Google for "AC mains transients cause" or what ever it is that you are looking for information on. It works wonders.

  • @joesmith-je3tq

    @joesmith-je3tq

    4 жыл бұрын

    Wiki even has a page for you: en.wikipedia.org/wiki/Voltage_spike

  • @MarcusMussawar

    @MarcusMussawar

    4 жыл бұрын

    @@joesmith-je3tq thank you and thank you for the video amazing work a bit concerning seeing how easy it is to cause the meter not to read

  • @joesmith-je3tq

    @joesmith-je3tq

    4 жыл бұрын

    @@MarcusMussawar That's the problem I see with it. I like the concept and did some patent searches on people have done it. Maybe someone will get the technology to be a little more forgiving than this one is.

  • @mikeadler434
    @mikeadler4346 ай бұрын

    👍👍

  • @dosgos
    @dosgos6 жыл бұрын

    Self-testing!

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