Fluke vs. Chinese Megohmmeter
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- Опубліковано 11 лип 2018
- In this video, we test a high-quality Fluke megohmmeter vs. two types of cheap Chinese megohmmeter from Amazon and see how they perform. We are NOT assessing durability or safety; we are merely testing the functionality.
Megohmmeters test winding breakdown over time. You generally take megohm measurements periodically and compare them over time to see how the windings fare with aging and long-term use. You can also use them to test insulation on wires. These meters use high voltage to get their readings (from 250v to 1000v; the Tianyu has fixed voltage at 500v). When testing motors with a megohmmeter, make sure they are de-energized and that you measure from winding to ground, NOT winding to winding.
Pay attention to manufacturers' specifications to see which megohm ranges represent potential issues and which ranges represent failure. Also, DON'T use megohmmeters on electronics, energized circuits, or anything that you don't know the maximum voltage rating of.
The Fluke megohmmeter can be used for category 3 or 4 applications; the Victor one can be used for category 3 applications, and the Tianyu megohmmeter doesn't have a rating that's easy to see.
We try out each megohmmeter on a couple of different resistors (200 megohms and 20 megohms). On the 200-megohm resistor, the Fluke measures 214, the Victor measures 216, and the Tianyu measures 200. On the 20-megohm resistor, the Fluke measures 19.7, the Victor measures 28, and the Tianyu measures 20. All of them are serviceable and function similarly, but that doesn't account for longevity or safety.
Read all the tech tips, take the quizzes, and find our handy calculators at www.hvacrschool.com/
Great video Br”y”an. Thank you, and keep em coming.
megohmmeters are a great preventive maintenance tool to have on the truck. Primary purpose is not just testing for high resistance grounds, it is for evaluating the refrigerant and oil atmosphere that a hermetic compressor is exposed to. As moisture and contamination in a system increases, the megohmmeter reading will decrease. On large equipment, the major motors and compressors are megged as a part of annual maintenance. Base-lining the reading on start up, and tracking the reading over time, is a great way to evaluate the atmosphere that a hermetic motor is living in. Potential compressor failures can be detected, and the equipment taken off line before a major burn out, which would create a huge cleanup job.
One rarely discussed benefit of Chinese-to-Amazon products like these is that western brands are often slow to adjust what they charge to the consumer as their manufacturing costs inevitably and continuously go down. I’m happy to pay extra for electronics when they are (very rarely) produced at living wages, especially by US workers, but you have to wonder how much the profit margins for Fluke, etc. have widened at our expense over the past 10-15 years when they are currently charging 1200%+ over their cheapest competitors. I don’t know anybody in the trades who takes home profits like that. Seems unreasonable to me.
if you open up the fluke, most of components are from china. for profit margins, fluke has to respond to its shareholders.
Its a 20% resistor, so a 200 meg resistor could be exactly that or 20% in either direction of that. You can't say which meter was correct unless you know you had a very specific value to begin with. Suggest you buy a 1% resistor or even .1% and keep it only for calibration checks if calibration is really that important to you.
.1% resistors in that resistance range are pretty much nonexistent.
The vici is a good quality continuity/ insulation resistance tester . And is used to test electrical installations mainly domestic . The fluke is a fantastic meter the other meter is a kewtech made for the Australian and American market and again is a fantastic meter that and the vici are very capable meters. Oh and you should always carry out the insulation resistance test at five hundred volts on circuits of 50v to 500 v and any thing less than 50v you test at 250v and if there is any sensitive equipment in circuit you test at 250v or test line and neutral combine to earth
Great video thank you
I think that this B&K Precision 307A Analog Megohmmeter @ $167 stands in the middle ground of Fluke expense for a unitasker and rather inexpensive imports. Thanks for the video. Very informative.
great video btw.... TQ . im currently using megger/ megaohmmeter mostly to test ultrasonic piezoelectric . trying to review the item 1st before buying the cheap 1
thank you very much for the demo . very helpful .
Correct title would be “Expensive Chinese Meter vs Cheap Chinese Meter”
good video,how well goes those tools work on automotive circuits ,12-14 volts, and other things on cars, i am a GM mechanic but am interestested in new technology
6:06 yup...it is a 20% rated resistor...so bang on!
What’s your opinion on the supco m500 as far as hvac use? Thanks
I just received as a gift a Fluke 1587. Its a fantastic tool that is quality made.
I have the UNI-T UT505A Insulation tester. Good meter and only $200.
Crazy how accurate the cheapest was, and for some reason I love dials and needles vs just a digital readout. I gues the leads you did not use on the fluke is the remote test lead.That is a really handy thing to have that the fluke offers.
Analog meters do have advantages in some situations, specially when you have fluctuations, where a digital meter will just have digits flying all over the place, with a analog meter you can "see" how the meter moves, and it will tell you something about what you are measuring. back in the day, I used to use a VTVM. the advantage was its very high impedance giving more accurate readings in live circuits.
@@agriperma when it comes to phone lines you could see it rise and drop in the wind and you knew you had a rusty exposed overhead line as it slowly wavered back and forth in the breeze.
I love the comparison the victor looks alright but you can’t beat the Fluke takes the guess work out of finding the proper values to test the resistance, Thanks for sharing the experience
Great explanation, thank you
Have had the Victor unit for over a year, but only used it once.
So at about $40 it paid for itself already I would imagine.
Good video.
Awesome as always
Love my HIOKI and Flukes.....but also have a few 20/50 buck thingies....For work I mostly use the Megger MIT1525 but cannot compare with any of these,(only pricewise it is insane....> 6K $)
Thanks. very helpful👍
Power = Voltage squared / Resistance, I believe you had plenty of room with power on them resistors, looks like the 20 meg resistor will handle 4.472 Kv. , that’s if you can believe it’s a 1 watt resistor, it looks like an 1/8 watter to me which would mean about 559 V tops and that looks a little more reasonable to me, I don’t see that tiny little thing dissipating a full watt, i’ll bet the thing got warm ! Also I kinda liked that Chinese meter but it doesn’t look too durable. I’d go with the fluke, if I could afford the thing that is.
hello bro. can it measure earth resistance?
Thanks for this great video ! What is and how do you the "ground" port on the tester?
Sorry but your question makes no sense. Please re-do.
Fluke is money well spent.
That being said, interesting results.
Good video. Also, don't ever meg a compressor while it's in a vacuum.
That's a government test question
And why dhose meters give different reading
Can you review supco m500
Wanted to see your video but the ads before the video are just too long.
7:14 Design-wise thisone looks like my HIOKI....Not the colorscheme though...
Can you redo the Tianyu non digital one again? you never turned the light on during the reading, i couldnt see it. redo the video with the light on
Why should you never megger a motor winding when motor is under vacuume?
Vacuum is a perfect insulator. You will get a false reading.
I guess I'll start off with the cheap one and get a proper one once I get a raise lol.
um ... where's the nist cal results ? the chinese stuff often drifts over time, not always ( the low end fluke's are made in china) but so far for me fluke, gossen metrawatt agilent are my primary meters due to cal issues. Uei seems to hold its cal pretty well too- remember that CE means bupkiss , its totally self regulated and fluke is UL and tuv/etl listed... so seeing CE is just wasted ink , often the voltage movs, safety dividers arent there. so remember around high energy as in commercial work , when you get arc flash and loose your hand or arm blown off.... well you saved $700 bucks.
👍👍
Pull mine "off the truck" multiple times a day.....
Bom dia de portugal
?Who’s been zapped by one of these meters? What kind of shock are we talking about? A MSD ignition module firing into one hand and out the other kind of shock? Or a little teensie weensie 500v shock that might knock your purse right out of your hands? 😂
I think the question which of them to use is depend By a professional.
If you are professional electrician you cannot use the Chinese isolation tester
Yes you can in the Uk there is no regulations or legal requirement that determine what meters you can or can’t use, BS7671. IET wiring regulations on requirement is that the test meter has no external damage is in good condition and the test leads conform to GS38 and the meter ice calibrated at least every twelve months.
My friend, you try to use a very low end Chinese product to do the testing!!!!!!!!!!!!!!!!!!!
Fluke is like u driving a Ferrari to reach a destination......Chinese product is like u driving a normal car to reach a destination....it still serve the purpose...... expensive does not mean it get your job done...what if people dun have money to spend on such expensive fluke....
I'm surprised how good Chinese tools have gotten. They are not as durable but they still get the job done. Just take care of them and don't drop them.
Plss be direct.
Chinese makes super cheap quality device.
BE Fuddle