“Blown” Fuses in Several New Multimeters - Page 1
Forum section: electronics / testgear

author: Locator
author_rank: Contributor
timestamp: September 05, 2024, 06:41:35 am
content: I’ve run across something that is very perplexing to me. The other day, I accidentally checked 110v AC house voltage with my Fluke 117 on the AC current setting. Of course, the outlet sparked and it slightly damaged the tip of the probe. The multimeter did not turn off, but I thought I probably blew the fuse… Only time I’ve ever done this, but it was a moment of getting distracted and I kicked myself for getting distracted….I opened it and tested continuity on both fuses. One of them did not work with continuity and also showed “OL” when checking resistance. Both tests were done with a brand new Fluke 179. Okay, I suppose I need to order a fuse from Fluke (I’m assuming 110v AC will blow the 10a fuse?)Then, just out of interest, I then opened up the brand new Fluke 179 and tested both fuses in the 179 (out of the meter). One of them was open - no continuity. (Checked with a new Fluke 87V.) What?? This was a brand new meter and the only thing I tested with it, for function was continuity, the resistance of the leads, a couple of AA alkaline batteries and the AC house current. IN the AC voltage setting - NOT in the current setting. I wondered if maybe it was a return to Amazon and someone else blew the fuse and sent it back, I don’t know.Then, for fun, I checked the 87V. both fuses showed continuity.Then, I checked two Brymen 257’s (actually, Greenlee DM-510a’s). Both fuses were okay in these.Then, I opened a Brymen 827 (it was a Greenlee DM-830a) and the larger fuse was open - no continuity. I purchased this new from Amazon a few years ago and it has led a pampered life - barely used. And, never any current. It was only tested with continuity with the leads a few years ago and kept in the case.Now, I had a couple of fuses on the workbench that I took out of a dead Klein MM6000 I had for years. It also had a pampered life and had only checked continuity a handful of times and the resistance of the leads. I took it out of the case a few months ago and the display was dead. I figured it was because it was a Klein, as I have had two other Kleins die a long time ago. I removed the two fuses - 1000v and 600v and kept them for spares. I checked them for continuity after doing all the other checking and BOTH of them were open. No continuity. Checked with a perfect Fluke 87V.And last one - I have an Amprobe AM-570, that I also bought new (all of these meters were bought new). It has only checked DC voltage and continuity. Also used it to check 110v house AC to check its’ accuracy compared to the Flukes. BOTH of its’ fuses were open - no continuity.Any thoughts on how I ended up with all of these dead fuses? They are all the factory fuses that came in the new multimeters and the only one that I evidently damaged was the Fluke 117. These things are the poster children for perfect condition multimeters.I know it sounds like these meters have been in the hands of a careless user, but they’re hardly used and I am the only one that has touched them.Shouldn’t ALL fuses in multimeters show continuity when tested?

author: Jeroen3
author_rank: Super Contributor
timestamp: September 05, 2024, 07:59:02 am
content: Did you do this with the wires you used to measure 120V of AC current? Because I've seen flimsy wires get damaged by it.Genuine fluke wiresprobablynot, but you should check anyways.(I've also evaporated the probes once with exactly the same mistake as you, only on a bigger socket, not fun)

author: wraper
author_rank: Unknown
timestamp: September 05, 2024, 08:11:39 am
content: Quote from: Locator on September 05, 2024, 06:41:35 amDo you mean you tested AC voltage? Selected switch position does not matter for this. If the probe was plugged into 10A or 400mA socket, it will blow the fuse.

author: Fungus
author_rank: Super Contributor
timestamp: September 05, 2024, 08:21:19 am
content: Meters don't have to be in "amps" setting to blow a fuse.It's enough just to have the cable in the "A" connector when you try to measure voltage.You don't need voltage to blow a fuse, just amps. You can blow a fuse with 1V if there's enough amps.

author: Locator
author_rank: Contributor
timestamp: September 05, 2024, 08:23:08 am
content: Quote from: Jeroen3 on September 05, 2024, 07:59:02 amIf you mean, did I test each of the fuses with the damaged leads, no - they were set aside so I could clean them up, later. The tests were done by two different sets of Fluke silicone-insulated leads that I had ordered to replace the factory leads that come with the multimeters.

author: Locator
author_rank: Contributor
timestamp: September 05, 2024, 08:27:25 am
content: Quote from: wraper on September 05, 2024, 08:11:39 amI had the red lead plugged into the 10A port and the black lead plugged into COM on the 117, when it happened. The setting on the dial was set to “A” for AC Amps. What happened was, I had just checked current before this and then went to check voltage on this outlet. I accidentally left the leads in the current ports and the dial on “A” (AC Amps). I inserted the probes into the 120v socket without thinking about the mixup. I shouldn’t have been juggling two things at once - I knew better than that, but just got distracted and in a hurry.

author: Locator
author_rank: Contributor
timestamp: September 05, 2024, 08:30:21 am
content: Quote from: Fungus on September 05, 2024, 08:21:19 amYep, this was exactly my mistake. I may have mixed up some of the details in my long OP diatribe, but the dial was on “A” and the red probe was plugged into the 10A current jack and I “tested” voltage on the outlet. (Good grief, every time I think about it, I could kick myself. And on a new meter, too.)

author: Phil1977
author_rank: Frequent Contributor
timestamp: September 05, 2024, 09:08:33 am
content: There are two types of DMM users - these who have connected voltage to the current input and those who will.

author: modoran
author_rank: Regular Contributor
timestamp: September 05, 2024, 09:35:11 am
content: .. and those who just doesn't have any current jacks on their DMM at all or never changes the leads position.

author: Gyro
author_rank: Super Contributor
timestamp: September 05, 2024, 09:39:31 am
content: With due regard for your history in hazardous CRT TV repair...Never poke standard DMMs into mains outlets, fuseboards etc. Firstly there's nothing to see there that is interesting enough to justify their resolution, and secondly, they are not intrinsically safe (read idiot proof - we are all idiots waiting to happen). UseElectrician'stools.In this case, you want a 2 pole voltage tester (not one of those crappy single pole or non-contact ones). I don't have visibility of what is commonly available in the US, but in the UK you would use something like the Martindale VT25, Kewtech KT1710 (or KT1780 if youmusthave a digital display). Fluke T5 etc.They are 'idiot proof' - no switches, no sockets, no fuses, they still give a voltage indication if the battery is flat or missing, and have safe continuity test. Above all, they have high CAT ratings for far less cost than the equivalent DMM. Ideally get a proving unit too, or at least, test on known live, before and after checking the circuit.

author: indman
author_rank: Super Contributor
timestamp: September 05, 2024, 09:45:01 am
content: Quote from: Phil1977 on September 05, 2024, 09:08:33 amI can add one more mandatory step, which is usually done after purchasing a DMM - measure the strength and power of the current in a ~220V/110V outlet!

author: Fungus
author_rank: Super Contributor
timestamp: September 05, 2024, 09:47:09 am
content: Quote from: Locator on September 05, 2024, 08:30:21 amYes, we understand this incident. I'm referring to all thoseotherfuses...

author: Fungus
author_rank: Super Contributor
timestamp: September 05, 2024, 09:49:10 am
content: Quote from: Gyro on September 05, 2024, 09:39:31 amAgree.Quote from: Gyro on September 05, 2024, 09:39:31 amPlug in a lamp, it tells you just as much info.

author: wraper
author_rank: Unknown
timestamp: September 05, 2024, 09:51:28 am
content: Quote from: Gyro on September 05, 2024, 09:39:31 amI'd never waste money on that overpriced garbage that cannot display the voltage with remotely reasonable accuracy. There is nothing wrong with using multimeter as long as you know what you're doing. IMHO those testers are for people who don't know one's head from a hole in the ground. Not to say for that money you can buy a quite decent multimeter with similar CAT rating. Heck, if you cannot plug the leads into proper terminals to save your life, cover amps sockets by sticky tape.

author: wraper
author_rank: Unknown
timestamp: September 05, 2024, 10:03:02 am
content: Quote from: Gyro on September 05, 2024, 09:39:31 amFluke 117 is literally an "Electricians Multimeter"https://www.fluke.com/en/product/electrical-testing/digital-multimeters/fluke-117

author: Gyro
author_rank: Super Contributor
timestamp: September 05, 2024, 10:03:44 am
content: Quote from: wraper on September 05, 2024, 09:51:28 amQuoteSorry, we're going to have to disagree on this one. Yes a lamp is intrinsically safe... as long as you test it on a known good circuit beforeandafter plugging it into suspect circuit.As far as the testers, they are there to protect life against itself. DMMs (as the OP has demonstrated) have far too many opportunities of error. As I said, we are all idiots waiting to happen!

author: Fungus
author_rank: Super Contributor
timestamp: September 05, 2024, 10:06:36 am
content: Quote from: Gyro on September 05, 2024, 10:03:44 amThat's true of multimeters as well.It's why they sell these:https://www.fluke.com/en/product/electrical-testing/basic-testers/prv240-proving-unitWithout one of those your meter/lamp can only indicate the presence of voltage, not absence.

author: Gyro
author_rank: Super Contributor
timestamp: September 05, 2024, 10:13:57 am
content: Quote from: wraper on September 05, 2024, 10:03:02 amAs in marketing speak for a bunch of features useful for a commercial electrician and decent CAT rating. It won't tell you that you are testing whether a circuit is live with the probes in the A jack and the dial set to Volts. It won't blow up in your face but it is not intrinsically safe in proving a circuit dead, i.e. If somebody dies from touching a live circuit, it won't be deemed adequate in court, non-contact test is unreliable. I'm veering towards commercial installations at this point of course.Read any of the manufacturers sheets (including Fluke) on safe isolation.

author: Fungus
author_rank: Super Contributor
timestamp: September 05, 2024, 10:17:34 am
content: Quote from: Gyro on September 05, 2024, 10:13:57 amDoesn't the Fluke 117 have input jack alert? If it doesn't then it should be kept away from mains AC.Me? I think the only "electricians meter" made by Fluke is the 113.

author: Gyro
author_rank: Super Contributor
timestamp: September 05, 2024, 10:26:50 am
content: Quote from: Fungus on September 05, 2024, 10:06:36 amYes,. Those proving unit's (that I mentioned) are sold for pre-post checking two pole testers as part of the standard safe isolation procedure. Unfortunately they won't power your lamp, hence you have wander off with it to find a live outlet. The sequence is... prove that the tester detects live voltage before, test the circuit and ensure that it reads dead, test the tester again to check that it didn't go faulty in the meantime. You can only assume that the tester worked last time, hence you need to check it again afterwards.

author: Gyro
author_rank: Super Contributor
timestamp: September 05, 2024, 10:34:19 am
content: Quote from: Fungus on September 05, 2024, 10:17:34 amNo, I can't see input jack alert in the specs (Unless I missed it). It just has things like Lo-Z volts to avoid ghost voltages, non contact volts (insufficient for safe isolation), Auto AC/DC volts (useful, checking an AC circuit on DC range is another accident just waiting to happen!). But certainly too many gotchas to consider it anywhere near intrinsically safe (for anything other than not blowing up in your face). Basically, it still relies on you not being an idiot... every single day.Edit: Yes, the 113 (+ Proving unit!) is better.

author: BeBuLamar
author_rank: Super Contributor
timestamp: September 05, 2024, 10:43:15 am
content: Nobody has answer for why brand new meters have blown fuse. I don't either except perhaps those are not brand new.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 05, 2024, 10:45:10 am
content: Quote from: Phil1977 on September 05, 2024, 09:08:33 amThat's called learning the hard way ... and paying to put a new fuseAnd now: process your setup mentally before doing any measurements to avoid this mistake again ...

author: coromonadalix
author_rank: Super Contributor
timestamp: September 05, 2024, 10:48:37 am
content: Quote from: BeBuLamar on September 05, 2024, 10:43:15 amI never saw this in many brand new meters i have bought : Mastech, Fluke, Beckman, Amprobe, bench or portable ... and all the old stuff i've bought ...The @OP must be incredibly unlucky ... ?

author: Fungus
author_rank: Super Contributor
timestamp: September 05, 2024, 10:52:34 am
content: Quote from: coromonadalix on September 05, 2024, 10:45:10 amMoral: Never ever put your meter away with the leads in the amps connector. Always move the leads back to the volts socket when you've finished measuring amps.(and get a meter with jack alert... I thinkallBrymens have it)

author: Gyro
author_rank: Super Contributor
timestamp: September 05, 2024, 10:55:23 am
content: Quote from: BeBuLamar on September 05, 2024, 10:43:15 amNor me. I'm sure Fluke and Brymen don't ship new meters with dead fuses, so I can only put it down to 'finger trouble' sometime in their short lives.

author: wraper
author_rank: Unknown
timestamp: September 05, 2024, 10:58:00 am
content: Quote from: BeBuLamar on September 05, 2024, 10:43:15 amIMHO the answer is quite clear:Quote from: Locator on September 05, 2024, 06:41:35 am"brand new"

author: Fungus
author_rank: Super Contributor
timestamp: September 05, 2024, 11:07:03 am
content: An AA battery is perfectly capable of blowing one of those fuses if the leads are in the wrong holes.

author: wraper
author_rank: Unknown
timestamp: September 05, 2024, 11:13:48 am
content: Quote from: Fungus on September 05, 2024, 11:07:03 amAlkaline most likely won't be able to blow 11A fuse, but can easily blow 440mA. A few NiMH in series (much lower ESR) probably will blow 11A fuse too, a single battery likely won't be enough due to multimeter lead resistance.

author: Fungus
author_rank: Super Contributor
timestamp: September 05, 2024, 11:17:45 am
content: Quote from: wraper on September 05, 2024, 11:13:48 amI didn't say which one.

author: Locator
author_rank: Contributor
timestamp: September 05, 2024, 08:47:09 pm
content: I get it - don't do it. That wasn't my question. Lead "alarms" wouldn't have helped and I'm not defending the 117 that I blew the fuse on. The leads were in the correct jacks for the dial setting - they were in the 10A jack and the dial was on the "A"/amps setting. There should not be no alarm showing in that case. The mistake was -Iaccidentally touched the leads to the outlet and blew the fuse when distracted. Got it. You're not supposed to do that, I get it...My question - and surprise/alarm is - I don't know why all the other bad fuses. And no, they were never used to check current, nor voltages with the leads in the current jacks. My assumption is I've received some previously used meters from Amazon. If you've bought much from Amazon, you have often received things people have returned. It's usually easy to tell, when the display protector has been removed or there is hair on the meter or the meter is turned backward, with a magnet against the face, or there is a return shipping label from some other Amazon customer in the package, etc...And I have plenty of devices to check that an outlet is working - I was checking the consistency of the AC readings on each of the meters. How else would you do that? Not that I need to give this info, either, but I personally keep plugs in the current jacks on my multimeters. It's something I rarely have to use, the aforementioned time, notwithstanding. I have clamp meters for that.And - WHY would checking alkaline batteries with DC voltage on any multimeter blow a fuse? It wouldn't.

author: Fungus
author_rank: Super Contributor
timestamp: September 05, 2024, 09:07:32 pm
content: Quote from: Locator on September 05, 2024, 08:47:09 pmNo, but people get the leads in the wrong holes.Bopttom line: No "new" meter would have blown fuses. If you're buying off Amazon and it arrives with a blown fuse then return it ASAP.

author: J-R
author_rank: Super Contributor
timestamp: September 06, 2024, 12:00:07 am
content: I've purchased two Fluke DMMs from the Amazon Warehouse that were returns. 87V and 287. Both were in great condition and came with third-party calibration data (per the listing), although the Bluetooth to IR adapter was missing from the 287. I contacted customer service and got a some money back. Was a steal of a deal.Anyway, long story short: neither had any blown fuses.However, plenty of used handheld and bench DMMs that I've purchased on eBay have had blown fuses. Obviously user error. But that is the job of the fuses. Most recent was a mint condition Fluke 45. The 10A input uses a 15A fast-blow fuse.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 06, 2024, 05:56:14 pm
content: I don't know about the flukes, but the Brymen meters beep at you when you have the test leads in a current plug while the rotary switch is in another position. My first meter did not have this (That was 30 years ago), and the first serious DMM I bought (Dynatek 112) also already had this. It's very rare to blow a fuse with such a meter. I also have a Wavetek Meterman XP35. I bought it in a pawn shop for EUR35. It also had it's fuses blown, even though this meter also has this bleeping function. So I replaced them, and had a fully working meter again

author: floobydust
author_rank: Super Contributor
timestamp: September 06, 2024, 07:22:08 pm
content: Fluke is looking at adding LED-rings to the input jacks as yet another way to stop jack mistakes from happening.But I'm sure we've all measured something on the mA range when current goes up a bit unexpectedly and takes out the fuse.One way to eat up fuses is automotive 12VDC work. Opening a door interior lamp, tap the brake pedal etc. and fuse blows while measuring parasite draw.I have seen really cheap fuses from china that had salt-water inside them. CorrosionYou could take apart your blown fuses for an autopsy.OP, I think unless you've got aliens borrowing your test equipment, you're buying defective products. Might be why the price is lower than the rest?

author: tooki
author_rank: Super Contributor
timestamp: September 06, 2024, 07:33:08 pm
content: Quote from: Doctorandus_P on September 06, 2024, 05:56:14 pmQuote from: floobydust on September 06, 2024, 07:22:08 pmDid both of you miss the original postand subsequent replywhere OP (re)stated that the problem was user error where the meter was in amps mode when the leads (in amps jack) were connected to mains? No input jack alert can prevent this, because it wasn’t a mode–jack mismatch error.

author: floobydust
author_rank: Super Contributor
timestamp: September 06, 2024, 08:17:37 pm
content: Having a bad day? Seeing your posts today giving people shit. Try not to blow a fuse.Yes I read the 117 fuse getting blown due to user (jack) error. Thread is about several new multimeters though.In OP, the 179, 827/DM-830, MM6000, AM-570 also had bad fuses and why?Post #30 "...I don't know why all the other bad fuses. And no, they were never used to check current, nor voltages with the leads in the current jacks..."

author: tooki
author_rank: Super Contributor
timestamp: September 06, 2024, 08:29:16 pm
content: Quote from: floobydust on September 06, 2024, 08:17:37 pmNope, I’m actually in a great mood. It just baffles me why people provide responses that ignore clearly- and repeatedly-stated information.Quote from: floobydust on September 06, 2024, 08:17:37 pmOK, and how would an input jack alert have helped here?

author: J-R
author_rank: Super Contributor
timestamp: September 06, 2024, 08:31:49 pm
content: Definitely some forums users could use a "quality over quantity" adjustment...My overall opinion of this thread is that the OP probably blew the fuses in the other DMMs but just didn't realize it at the time.

author: IanB
author_rank: Super Contributor
timestamp: September 06, 2024, 08:44:18 pm
content: Quote from: BeBuLamar on September 05, 2024, 10:43:15 amI have certainly bought a brand new meter that came with a blown fuse out of the box. A previous purchaser had bought it, blown the fuse, and then returned it.For as long as retailers have a policy of accepting returns, you run the risk of getting returned goods "as new".

author: Fungus
author_rank: Super Contributor
timestamp: September 06, 2024, 08:49:05 pm
content: Quote from: IanB on September 06, 2024, 08:44:18 pmAnd you have the option of instantly returning it as "damaged".Me? If I'm paying top $$$ for a multimeter I want to know its history.

author: floobydust
author_rank: Super Contributor
timestamp: September 06, 2024, 09:10:00 pm
content: Quote from: tooki on September 06, 2024, 08:29:16 pmPrevious post #33 was about the jack alert so I mentioned the LED-ring addition. Nothing can save a fuse. They are made to die.Threads usually are full of misunderstanding, side-channel issues etc. so I will not stay laser-focused especially when we don't know what went wrong and have to guess or speculate.Why do the other four or five new multimeters have blown fuses? That is not clear but likely user error I guess, before or after the resell.

author: thm_w
author_rank: Super Contributor
timestamp: September 06, 2024, 09:19:40 pm
content: Unless you are buying from Amazon Warehouse Deals (returned or damaged items), the chance of you getting this many returned "new" meters is low. Its possible but quite low. It also assumes you don't check the box tape when opening it, and notice that its already been opened.Quote from: IanB on September 06, 2024, 08:44:18 pmDefinitely, but, did you notice the packaging was opened already? Or was there no tape sealing the box.