Reputable source in EU/germany for multimeter fuses? - Page 1
Forum section: electronics / repair

author: nightfire
author_rank: Frequent Contributor
timestamp: April 02, 2023, 03:19:50 am
content: In my main handheld multimeter (U1272A) the 440mA fuse has decided to release the magic smoke some time ago- as I do not use it often to measure current, I detected it as of today...Agilent provided a 10x35mm 1000V fuse, ceramic- part nr. 50 210 06.This seems not to be in stock with the sources I normally order, also possible replacement models are not on the menu, or somewhat more expensive.I mean, if it is only the Fluke-provide BUSS fuses I can get, I also will happily put them in, but would like to be able to order from some other source where I pay around 10 € for a fuse and not 20+Questions here:- Are there any secret tips for mailorder shops that sell them? Or some big "usual" suspect, that I missed? (I order usually not from distributors like digikey, but rather consumer-oriented shops like Reichelt etc.)- Would it make sense to compile some list of manufacturers of multimeter fuses that are reliable, also for reference to other people?- Should I maybe start some new side-business and sell that stuff out of my livingroom? *g*

author: floobydust
author_rank: Super Contributor
timestamp: April 02, 2023, 03:57:07 am
content: That is a Siba part number. In Germany I would try them first.Multimeter fuses are a specialty item, with associated price-gouging and profiteering and fakes. They are ridiculously expensive.p/n 50-210-06/0.44A (or maybe 50 210 06.0.44) for 440mA 1,000V 10x35mm (not 38mm!) DMI (for digital measuring instruments) URZ series 30kA interruptRS Stock No. 736-1428

author: jonpaul
author_rank: Super Contributor
timestamp: April 02, 2023, 01:42:25 pm
content: ebay, Chinese sellers have all the specific VOM fuses.Alternative is Amazonj

author: nightfire
author_rank: Frequent Contributor
timestamp: April 02, 2023, 01:44:45 pm
content: Yes, but chinese sellers, that have Bassmann fuses (compatible Fluke...) or SIBA fuses for a third of what I am paying in germany for a SIBA fuse, are sources I am afraid of ordering...Also via ebay I actually only get resellers in the UK, which means a hefty premium for shipping.

author: tooki
author_rank: Super Contributor
timestamp: April 02, 2023, 02:01:07 pm
content: Quote from: jonpaul on April 02, 2023, 01:42:25 pmYou know better than to recommend either of those sites. Who knows what kind of crap counterfeit fuse you might get. Even if it’s not relevant for the OP, if they ever sell or give away that meter, the new owner might not know it has a potentially unsafe fuse in it. The OP asked forreputablesources and you list the most disreputable ones possible…

author: Messtechniker
author_rank: Frequent Contributor
timestamp: April 02, 2023, 02:12:24 pm
content: I wonder: what's behind the design decision of specifying10x35 mm fuses instead of the more common 10x38 mm types?To save 3 mm of space? Really?Conrad has your fuse:https://www.conrad.de/de/p/eska-dmm-44-1000-feinsicherung-x-l-10-3-mm-x-35-mm-0-44-a-1000-v-superflink-ff-inhalt-1-st-396821.html

author: tooki
author_rank: Super Contributor
timestamp: April 02, 2023, 02:33:15 pm
content: Quote from: nightfire on April 02, 2023, 03:19:50 amBasically, excluding Chinese no-name stuff, I am only aware of three companies that make the 440mA, 10.3x35mm multimeter fuse:Bussmann (DMM-B-44/100 or DMM-44/100-R)Littelfuse (0FLU.440T, FLU 44/1000)SIBA (5021006.0.44)Any of these are interchangeable and I wouldn’t hesitate to use any of them. My Fluke came with Bussmann, my Keysight came with SIBA.However, in practice you’ll find that the cheapest way to buy these (and be sure they’re genuine) is usually to get them sold by Fluke, as Fluke part number 943121.How about Conrad? They’re consumer-friendly and sell the Fluke-packaged one for €12:https://www.conrad.de/de/p/fluke-943121-dmm-b-44-100-sicherung-ersatzsicherung-440-ma-1000-v-1-st-126373.htmlIf there’s a Conrad shop near you, I think you can have it sent there and not pay shipping.Farnell has the SIBA ones at a great price:https://de.farnell.com/en-DE/siba/5021006-0-44/fuse-for-dmi-1000vac-dc-10x35/dp/1827166P.S.This old post of minecovers much the same info, but includes the 11A fuses, too.

author: wraper
author_rank: Unknown
timestamp: April 02, 2023, 02:38:19 pm
content: Either get them from Brymen or use SIBA. Fluke branded fuses usually have reasonable cost in pack of 5.https://brymen.eu/shop/fuse-0-44a-1000v-10x38-mm/https://eleshop.eu/multimeter-fuse-brymen.html

author: nightfire
author_rank: Frequent Contributor
timestamp: April 02, 2023, 02:42:21 pm
content: Thanks for the information so far!Conrad is one of the usual suspects I would consider to order- here is a hint that maybe applies to other german customers: Voelkner online shop also resells large quantities of goods with Conrad stickers on them, so I suspect they have some cooperation going on. But with Voelkner the exact same article is mostly significantly cheaper...After doing some homework, I think the Fluke branded Bussmann fuses will be the ones that I order- there is a reseller that has it for approx 10 € AND I have gotten some rebate coupon as "valued customer, please buy again" last week ;-)

author: wraper
author_rank: Unknown
timestamp: April 02, 2023, 02:42:50 pm
content: Quote from: jonpaul on April 02, 2023, 01:42:25 pmAnd you get fake junk.

author: tooki
author_rank: Super Contributor
timestamp: April 02, 2023, 02:44:34 pm
content: Quote from: Messtechniker on April 02, 2023, 02:12:24 pmOf course not. It’s a safety feature. It’s to prevent the user from inserting the two fuses into the wrong holders. With many meters that use these fuses (maybe all?) you’ll find that the housing of the multimeter won’t even close if the 38mm fuse is inserted into the 35mm fuse holder. That way, you can’t fry the low-current shunt by pushing 10A through it with the wrong fuse in. If you do the opposite, putting the 440mA fuse into the 11A holder, you’ll blow that fuse, but not the meter.

author: nightfire
author_rank: Frequent Contributor
timestamp: April 02, 2023, 02:47:17 pm
content: Quote from: Messtechniker on April 02, 2023, 02:12:24 pmUsually not only to save space, this is a rather nice side-effect. It prevents people from shoving the cheaper 10x38 fuses in it, and helps prevent a mixup of the bigger 10A fuses accidentally inserted in the wrong slot.A 10x35 inserted in the 10A slot will "only" act earlier, so no damage done, a 10A fuse in the <1A socket could cause significant damage.In 10x38 you get also some household characteristics with rated voltage up to 500V, or special stuff for motor starters etc.10x35 is more exclusive and mostly used for semiconductor protection.

author: Alti
author_rank: Frequent Contributor
timestamp: April 02, 2023, 03:57:51 pm
content: Quote from: nightfire on April 02, 2023, 03:19:50 amSo you want to buy the exact fuse cheaper, or you want to use different more popular fuse for this job?Do you need 1000V multimeter or you just did not think over this purchase? Maintenance of a CAT IV 1000V gear is naturally more expensive than CAT III 300V, do not be surprised.There are off-the shelf available fuses that can deal with 500V, prospective fault currents in 100kA range and those that have quite low i2t but I doubt you'll find the ones that suit Agilent.ETI 002620017is 1€, mind I have no idea what your job is, maybe you dive into 1kV 100F capacitor banks daily.

author: nightfire
author_rank: Frequent Contributor
timestamp: April 02, 2023, 04:29:59 pm
content: In the actual application I use my U1272A at home at my private "workbench". Mostly repair work of some appliances up tp 230V AC, and rarely measuring currents at this limit.Other than that, it is usually some electronics where the Voltage is below 25V.I got this DMM as a good shot on ebay, otherwise probably some lesser specc'ed DMM would live with me now...What I want is basicallly quality stuff, and as the shops that sell to private customers have whether no stock or a broad variation of prices, I am on the lookout for a reputable source that charges reasonable prices.Might sound nitpicking, but the lowest price (plus shipping) is aroung 10 €, and same stuff sells elsewhere for nearly 20 €- for the difference I can order a second fuse or some other stuff.What I definitely not want is fake stuff for a fraction of the price that is unreliable.Due to the issues to get SIBA fuses as a direct replacement, I would also be happy to put in a similar specified alternative, like the Fluke version with its OEMs- those have better availability right now and some of my frequented suppliers carry them.In case no supplier would have fitting replacements, I would have looked to replace it temporarily with another fuse with lesser rated voltage, as I actually do not need 1000V in my line of work.As I am familiar with reading the curves of fuses, I would have looked at similar breaking capacity and I²t values.

author: Detlev
author_rank: Regular Contributor
timestamp: April 02, 2023, 04:44:17 pm
content: unfortunately I also can't find any good shops where you can buy high-quality components. I wanted to buy two Radiall cables from RS (500€), after ordering I got an email that I was not being supplied.Ordering in the US is actually out of the question for me.Buying expensive measuring devices is not a problem, but it fails with an HF cable....

author: tooki
author_rank: Super Contributor
timestamp: April 02, 2023, 04:47:18 pm
content: Quote from: Alti on April 02, 2023, 03:57:51 pmHow is any bit of this response helpful?!?The one you link to is the wrong size, with me already having explained in detail above why that size won’t fit.If you knew anything about themultimeterfuse market, you’d know that there aren’t any cheaper alternative fuses. Very few fuses exist in the necessary size (10.3x35mm), and the alternatives are not cheaper!

author: tooki
author_rank: Super Contributor
timestamp: April 02, 2023, 04:51:46 pm
content: Quote from: nightfire on April 02, 2023, 04:29:59 pmWhat “issues”? I already showed you where to get the SIBA fuse for €8. Just order enough stuff to meet the 55 euro threshold for free shipping. If not, it’s 8 euros shipping: “*7,95 € Versandkosten bei Bestellungen unter 55 € mit einer Lieferung in der Regel am nächsten Werktag.”

author: Alti
author_rank: Frequent Contributor
timestamp: April 02, 2023, 05:31:23 pm
content: Quote from: nightfire on April 02, 2023, 04:29:59 pmUse clamp meter for mains AC current jobs. You cannot blow a fuse in clamp ammeter.As for Agilent - you could convert a fuse holder for something of different size and most likely lower ratings, and downgrade measurement rating. Other option is to use lead with external fuse holder and i2t smaller than i2t of internal fuse. A fuse protecting the fuse. Not very practical dangling fuse but if one musts.. IEC60127-2/1 fuses cost 1€ for 10-pack.Quote from: tooki on April 02, 2023, 04:47:18 pmNot only size is different but also voltage, current rating and a bunch of other points of specification. My post was to show OP that one can buy a 500mA range fuse that can deal with 400VAC and 100kA environment (and most likely higher i2t), for €1. It was hard to guess from our 1kV capacitor bank expert posts what he really needs. It seems even that fuse is overkill for his "repair work of some appliances up tp 230V AC" needs. "Repair work of appliances" is CAT II and he won't find voltages exceeding 250V in there.

author: floobydust
author_rank: Super Contributor
timestamp: April 02, 2023, 05:42:02 pm
content: Bussmann fuse prices are off the charts in North America, USD$75for the DMM-B-44/100 !I wonder if they are better priced in Europe?2012 Eaton buys Cooper $12B (Bussmann) and jacks up the price - I even emailed Eaton and flamed them to no effect regarding their highway robbery.

author: nightfire
author_rank: Frequent Contributor
timestamp: April 02, 2023, 05:54:32 pm
content: @tooki: I wanted to tell Alti that this was the originating issue, that on first glance lots of overpriced offers were about to be seen- but luckily, some decent offerings appeared with suppliers that seem to have the stuff in stock@Alti: The things I measure with mains reference are usually too small to give correct readings on a clampmeter. I measure leakage currents and such, or the power consumption of E27 lightbulbs with LEDs- here we are talking about mA. And a proper leakage current clamp is actually not in the upper third of my wishlist...@floobydust: By chance, I went to Welectron and could see Bussmann fuses there, 9,50 € each plus shipping ;-)But this is dangerous- they also could supply me with lots of things that could trigger some GAS :-)

author: Alti
author_rank: Frequent Contributor
timestamp: April 02, 2023, 06:10:38 pm
content: Quote from: nightfire on April 02, 2023, 05:54:32 pmI am not sure what this Agilent can but something tells me you cannot measure power with it. As for measuring small currents of mains powered LEDs then you must know these usually start from rectifier and huge capacitor so if you want to use €10 super fast 400mA fuses for that - be prepared for expenses.

author: nightfire
author_rank: Frequent Contributor
timestamp: April 02, 2023, 06:19:52 pm
content: For reference, maybe it helps others, I compiled some data from several datasheets and information of suppliers.Stuff is still incomplete, as it was not easy to get detailed datasheets of some fuses from the manufacturers website in a hurry.Basically it boils down to the following facts:If you want or need a 1000V fuse for your DMM in 10x35 or 10x38, there are basically SIBA, Bussmann and Littelfuse that manufacture the fuses that you can get in the USA or EU. Popular rebrand is Fluke with its own part numbers. Depending on the supplier and package size, those might in some countries easier to get.Manufacturer Number Extension Size (mm) Rated Current Rated Voltage breaking capacityAmpere Volts kASIBA 5021006 440 10x35 0,44 1000 30SIBA 5021006 400 10x35 0,4 1000 30SIBA 5019906 10 10x38 10 1000 30SIBA 5019906 „05“ 10x38 0,5 1000 30SIBA 5019906 1 10x38 1 1000 30Bussmann/Eaton DMM-B-44/100 10x35 0,44 1000 10Bussmann/Eaton DMM-B-11A 10x38 11 1000 20Fluke 943121 10x35 0,44 1000 10Fluke 203403 10x38 11 1000 20Fluke 203411Fluke 2279229 6,3x32 0,315 1000Fluke 803293Littelfuse FLU.440 10x35 0,44 1000 10Littelfuse FLU011 10x38 11 1000 20Ferraz Shawmut FSM44/100Ferraz Shawmut FSM11

author: shapirus
author_rank: Super Contributor
timestamp: April 02, 2023, 06:22:45 pm
content: Quote from: floobydust on April 02, 2023, 05:42:02 pm$12-$25 in Ukraine, and consider yourself lucky if they're in stock. Last time when I fried the DMM-B-44/100 in my BM869s, they weren't in stock locally, so I had to order some from Aliexpress. Got two lots: one was $5.23 for 2 * DMM-B-44/100-R, another was $10.80 for DMM-44/100-R + DMM-11AR. No idea whether they are genuine, but they look the same as the genuine ones. When I shake them, I can hear the sand filling inside. I'll try my best to avoid verifying that they blow at the rated current though.I measured their resistance with a TR-1035+:DMM-11AR: 9.0 mOhmDMM-44/100-R: 758 mOhmDMM-B-44/100-R: 760 mOhmIt would be interesting to compare them to some definitely genuine fuses of the same type. If someone has them and can measure resistance, please do and post results.

author: nightfire
author_rank: Frequent Contributor
timestamp: April 02, 2023, 06:26:04 pm
content: Quote from: Alti on April 02, 2023, 06:10:38 pmYes, there is no real energy measurement mode like in the Gossen Metrahit Energy or Voltcraft VC870, but can get some rough idea what I have in front of me. In the near future this setup will be refined to get along with probably the 3-multimeter method for measuring energy consumption.

author: tooki
author_rank: Super Contributor
timestamp: April 02, 2023, 10:18:30 pm
content: Quote from: floobydust on April 02, 2023, 05:42:02 pmNope, the prices are no better here, which is why the advice is the same: buy them repackaged from Fluke.I don’t think the Eaton purchase has anything to do with it, they’ve always been expensive.

author: mwb1100
author_rank: Frequent Contributor
timestamp: April 02, 2023, 10:32:50 pm
content: welectron.com has the Bussman 440mA 1000V HRC fuse (10 x 35mm), IR 10kA for 9.50 EUR. I believe they ship within Germany for free.I'd be very surprised that that fuse's specs didn't match the Agilent specs exactly.-https://www.welectron.com/Cooper-Bussmann-DMM-B-44-100-R-HRC-Fuse-044A-1000V

author: tooki
author_rank: Super Contributor
timestamp: April 02, 2023, 10:50:03 pm
content: Quote from: Alti on April 02, 2023, 05:31:23 pmAnd what does that information accomplish, since such a fuse cannot be used since it physically will not fit?!?

author: tooki
author_rank: Super Contributor
timestamp: April 02, 2023, 10:53:01 pm
content: Quote from: mwb1100 on April 02, 2023, 10:32:50 pmDespite showing the Bussmann and saying that in the heading, the specs and datasheet indicate it’s the SIBA fuse, which is what Agilent/Keysight ship with from the factory.The specs aren’t 100% identical between brands (the SIBA fuses have a significantly higher interrupting rating than the Bussmann and Littelfuse) but all the same I’d consider them to be completely interchangeable.It’s free shipping on orders above €80, so buying that fuse from Farnell is significantly cheaper in the end.

author: mwb1100
author_rank: Frequent Contributor
timestamp: April 02, 2023, 11:17:59 pm
content: Quote from: tooki on April 02, 2023, 10:53:01 pmThe datasheet link in the welectron page is for SIBA, but it not for the SIBA 50-210-06. It's for the SIBA 7017240 series (the SIBA fuse the welectron catalogs). I figure it's just an error by welectron.Quote from: tooki on April 02, 2023, 10:53:01 pmYou right about the interrupt rating. The Bussman fuse IR is 10kA, the SIBA IR is 30kA (frompage 24 of this datasheet). I am surprised by that difference, but not as surprised as I thought I'd be.

author: tooki
author_rank: Super Contributor
timestamp: April 03, 2023, 11:10:22 am
content: Quote from: mwb1100 on April 02, 2023, 11:17:59 pmOh, you’re right. I looked at it on my phone before and I guess I didn’t scroll around enough. On a larger display it’s clear that the page is shared by three different fuse types.

author: nightfire
author_rank: Frequent Contributor
timestamp: April 03, 2023, 04:36:34 pm
content: Quote from: mwb1100 on April 02, 2023, 11:17:59 pmTo put that in perspective: Environments that can and will all of a sudden spit >1000 Amps at you are usually environments where one does not simple puts a multimeter in series with some circuit to measure Amps- mainly because the wires have the diameter of the whole multimeter ;-)Rule of thumb, that I have memorized whilst learning about short circuits calculations: It does not matter how beefy your transformer is, after 3 meter of 1.5mm² cable (standard installation size in germany, rated 16A permanent load), you can have a maximum of roughly 2000 A short circuit power.So, an interrupt rating of 10 kA is fine for me.Question here would be, if Bussmann deliberately rates the fuse lower than it could perform, so that even old and aged equipment will still perform to spec?(Remembering possible military contracts etc. in the US)

author: py-bb
author_rank: Regular Contributor
timestamp: April 03, 2023, 04:52:52 pm
content: Quote from: tooki on April 02, 2023, 02:01:07 pmIME the fuses usually come in packs of 10 - why not test one of them? I do this because someone once freaked me out with rumours to this effect but fuses (at least easy values < 750v and < 20A) are not exactly difficult devices - it's right up there with a knock-off pencil - it's still a pencil!

author: Alti
author_rank: Frequent Contributor
timestamp: April 03, 2023, 06:43:50 pm
content: Quote from: nightfire on April 03, 2023, 04:36:34 pmThe fuse is there not when you measure current in series with some circuit but rather what happens afterwards, when you stick leads into a low impedance mains socket, when still in ammeter setup.

author: py-bb
author_rank: Regular Contributor
timestamp: April 03, 2023, 07:30:46 pm
content: Also with the 1000 amps thing that will blow the hell out of the fuse, as long as the voltage is <= fuse rating, you're good.For example a 250v fuse means "if it blows it will block <= 250v (absolute)" - if you put say 2.5kv there that'd just arc the gap and it's possible the fuse is no longer a fuse and conducting quite happily.So with the 1000 amp thing - this example presents no problem AS LONG AS the voltage rating is within that of the fuse.

author: floobydust
author_rank: Super Contributor
timestamp: April 03, 2023, 10:21:20 pm
content: Quote from: py-bb on April 03, 2023, 07:30:46 pmYou are wrong, where are you getting this from?Look at the fuse safety standards, UL 248 the test jig is set up "short circuit current in rms symmetrical amperes equal to the interrupting rating of the fuse to be tested."Typical lowest rating is 10kA and they do test to that high current (bigger fuses to 200kA), with series inductors, inducing an arc inside the fuse to 3kV. It's all about taking the arc.The source test voltage I think is the fuse's RMS rating, so 1,000VAC."The fuse shall operate and permanently clear the circuit without damage to the components of the complete fuse within the following parameters:a) there shall be no re-establishment of current. If evidence of a tendency to restrike is noted, application of the recovery voltage shall be continued for 60 s past the time of restrike;b) the fuse shall not emit molten metal;c) no external soldered connections shall melt;d) the fuse shall not exhibit movement nor deformation of either or both end caps that would result in more than 3.2 mm (0.125 in) increase in overall length;e) there shall be no holes in the fuse as a result of this test;f) the fuse body may discolor but shall be readily identifiable for replacement purposes;g) for fuses with glass or ceramic bodies, cracking of the body is permissible provided that the fuse remains in one piece, without loss of filler, prior to removal from the holder or test rig; andh) for the threshold test, fuses shall clear in the first half cycle after closing."

author: py-bb
author_rank: Regular Contributor
timestamp: April 04, 2023, 03:55:27 am
content: Quote from: floobydust on April 03, 2023, 10:21:20 pmThe first sentence seems to be wrong:Fuses have both a current and voltage rating. They only guarantee they will cut the circuit when the (absolute) voltage is less than their rating. Incase you have not encountered this wording a 250v fuse will be OK with -250v or +250 across it, but not -300v or +300v.You must obey BOTH if you want protection.I will restate it again (even though I think it was perfectly clear) - enough volts will arc at some point. If you put say 100kv across it (so a really big static shock) - it's just going to arc the gap in the fuse. If there's enough current this can ionise the gas in there and you get a consistent arc.Fuse voltage ratings are meaningful and importantas I said.

author: nightfire
author_rank: Frequent Contributor
timestamp: April 04, 2023, 06:38:43 pm
content: Correct. Fuse voltage ratings are important, and having a very high-voltage spike can certainly do havoc.In real applications, a slightly higher voltage than rated voltage usually causes no direct immediate harm, but causes higher heat dissipation than the fuse originally was designed for.And this can lead to some other significant issues in the surrounding.

author: floobydust
author_rank: Super Contributor
timestamp: April 05, 2023, 01:14:50 am
content: What is "with the 1000 amps thing" ? Fault currents on mains can be very high. I notice UL is 10kA basic yet IEC is 1kA, so fuse standards are different and this might be an issue.

author: py-bb
author_rank: Regular Contributor
timestamp: April 06, 2023, 02:26:57 am
content: Quote from: floobydust on April 05, 2023, 01:14:50 amPeople often think of something that could provide say 1000A (at a low voltage) as inherently dangerous because of 1000 amps "being available" - I used it as an example to show that "even if your supply could provide 1000 amps as long as the fuse's voltage rating is >= supply voltage" the fuse will (safely) blow and break the circuit.Contrast with many thousands of volts available on say a 250v fuse - it blows and then it'll just arc across the gap, the fuseis not guaranteedto be able to break this circuit (increase voltage as necessary to prove point)

author: tooki
author_rank: Super Contributor
timestamp: April 06, 2023, 07:00:53 am
content: Quote from: py-bb on April 06, 2023, 02:26:57 amDid you mean to writethousands of amps?

author: Alti
author_rank: Frequent Contributor
timestamp: April 06, 2023, 02:35:53 pm
content: Right, fuses have their envelope of operating parameters and work in limited range. The standard or datasheet does not give the shape of the envelope but just points inside of safe zone.BTW, any interesting YT with some spectacular kills?I remember I have seen a training video of a 50kA fuse (IEC60269?) that was purposely blown in 100kA or 200kA circuit just to show how to ruin one's day by exceeding envelope. I just cannot find this YT..

author: nightfire
author_rank: Frequent Contributor
timestamp: April 06, 2023, 04:40:32 pm
content: Quote from: tooki on April 06, 2023, 07:00:53 amI would think py-bb meant Volts, as the Volts ultimately are driving the Amps... Also you need higher distance/clearing between the electrodes/poles of a fuse to really be able to break down the arc that is created for a moment.There is a good reason why the 1000V fuses in a multimeter are longer than the small glass 5x20mm fuse foir household applications...

author: floobydust
author_rank: Super Contributor
timestamp: April 07, 2023, 02:17:26 am
content: It would be nice to up the technology so that a 5x20mm fuse could be used in multimeters (above 250VAC) instead of the huge 10x38mm parts. I thought of the exploding fuses used in electric utility distribution transformer primary protection, like 25kV lol. Those are really loud like a gunshot.I think not much in fuse technology has improved in many decades, and here is Eaton asking $75 for the same old fuse a step aboveHenry T Bussmann's 1919 patents.

author: KaneTW
author_rank: Frequent Contributor
timestamp: April 07, 2023, 04:04:53 am
content: The short circuit current past NH 100A fuses is limited to less than 10kA and additionally limited by the meter and other fuses. Realistically it will be less than 6kA in the main panel and less than 2kA at any outlet.German residential panels rarely (never?) have fuses above 100A.

author: Alti
author_rank: Frequent Contributor
timestamp: April 07, 2023, 11:41:09 am
content: Quote from: floobydust on April 07, 2023, 02:17:26 amHow many people out there are willing to "I measure leakage currents and such, or the power consumption of E27 lightbulbs with LEDs- here we are talking about mA." on a circuit that goes beyond 250V? I am afraid you are the only one. There are no markets for 400V or 500V LEDs with mA leakage. BTW, clamp meters go well below mA range and there are those optimized for low ranges, those for RCCB leakage tests.

author: tooki
author_rank: Super Contributor
timestamp: April 07, 2023, 02:37:19 pm
content: Quote from: nightfire on April 06, 2023, 04:40:32 pmYyyyeah…. But I don’t see what your reply has to do with mine.My point was that the sentence “Contrast with many thousands of volts available on say a 250v fuse…” makes no senseat all. Volts are not “available” (amps are available). Volts are applied.

author: nightfire
author_rank: Frequent Contributor
timestamp: April 07, 2023, 03:55:26 pm
content: Ah yes- in this regard, correct.Volts are applied.The thing is, that depending on the amount of Volts there is a distance that has to be kept so that an arc can not happen. Filler materials as sand help extinguishing an arc, but nonetheless also the contacts of the fuse are to be placed at that same distance, otherwise an arc will form at this point if the voltage is high enough.So it makes sense that fuses grow longer, the higher their rated voltage is.Most multimeters that are rated for 600V use 6,3x32mm fuses, because they are long enough for this kind of voltage, and readily available.The lower the rated voltage, the shorter the fuses can be- for example, SIBA 70 007 40 is a 5x20mm fuse, FF characteristic, and 400V with 10kA rating.Above that, we are in the territory of the 6,3x32mm fuses.Also a point that bigger fuses allow for bigger contact area to the holders and bigger wire (or whatever shaped metal plates) in the inside, so potentially having a lower resistance and therefor dissipating less energy as heat.

author: tooki
author_rank: Super Contributor
timestamp: April 07, 2023, 04:20:47 pm
content: Who are you telling that to? I already know all of that. I made the apparently grave error of pointing out the presence of and asking for clarification of a nonsensical comment, it wasn’t a general request for clarification on the topic.

author: py-bb
author_rank: Regular Contributor
timestamp: April 07, 2023, 08:08:12 pm
content: Quote from: tooki on April 07, 2023, 02:37:19 pmSo you asked a question "what was that 1000s of volts bit about", I replied, as for the rest, let's read it again:Okay so when we speak of thousands of volts available imagine a special high voltage power supply - if you apply that a 250v fuse one of three things happens (unless by thousands of volts you mean so high it just arcs across everything - which would be many 10s or 100s of thousands)We may say a 9v battery has "9v available [across the terminals]" - it's maybe a British English thing but it's in common parlance.Anyway the three cases:1) Absolutely nothing - current is below the fuse's rating, there's a circuit, all is well2) Fuse pops creating a gap in the fuse wire - and the voltage isn't enough to arc across that gap -the "lucky" case, the fuse has done its job, even though you've abused it by going beyond the ratings3) Fuse pops but the voltage is high enough it just arcs across the gapso even though the fuse is blown it's still conductingApparently it (proper high voltages) can ionise the air (like a welding arc) and sustain this but I don't deal with the area.Make sense now? It's the same case wrapped up differently:You must pay attention to fuse voltage ratings!If the fuse were rated for the voltagethe manufacturer's are"guaranteeing that it should"be able to break the circuit at that voltage or less- so our 250v fuse would be fine in in a 100v system or whatever.It would be inadequate in a 600v system- it may still work and break the circuitbut you can't count on this and should get one rated for 600v

author: tooki
author_rank: Super Contributor
timestamp: April 07, 2023, 08:31:56 pm
content: Quote from: py-bb on April 07, 2023, 08:08:12 pmI asked if you meant amps instead of volts, since your sentence didn’t make sense. OTHER people replied, but YOU didn’t reply until now.Quote from: py-bb on April 07, 2023, 08:08:12 pmI categorically reject your claim that volts are “available” is common usage, British or otherwise. We have enough British members (and many more native speakers of other dialects of English, like me) here that if it were common, we’d see it here all the time.A voltage sourceprovidesorsuppliesa voltage, and a voltage isappliedto something else.You can say “I have 5, 9, and 12V available” to mean that you have those voltagesourcesavailable. But the source itself can’t have a voltage “available”.But it makes even less sense in your usage that I commented on: a voltage “available” at a load!

author: alm
author_rank: Super Contributor
timestamp: April 07, 2023, 08:46:06 pm
content: Quote from: tooki on April 07, 2023, 08:31:56 pmEveryone who responded except you understood what it meant. You are just being needlessly pedantic. Are you really claiming you could not understand what they wrote? It was obvious to me that the poster was talking about what happens if you exceed the voltage rating of a fuse. I think you could cut a non-native speaker (I'm guessing from the country flag) some slack.

author: tooki
author_rank: Super Contributor
timestamp: April 07, 2023, 09:14:32 pm
content: Quote from: alm on April 07, 2023, 08:46:06 pmThe only thing I originally asked that person was “did you mean to write amps?” I suspected (correctly, as it is) what they meant, but I asked for clarification just in case it wasn’t what they meant, because at face value it made no sense. That was all. The fact that they are likely not a native speaker is precisely why I asked for clarification in the first place!As for “it was obvious to me”… there is actually the well-known phenomenon (among language teachers and linguists, at least) that nonnative speakers will tolerate certain errorsmorethan native speakers, because native speakers’ parsing is more nuanced and precise to begin with. Same thing happens with pronunciation, where a native speaker’s expectations for how a certain word or sound is pronounced are narrower than for a nonnative speaker.

author: py-bb
author_rank: Regular Contributor
timestamp: April 09, 2023, 01:46:26 am
content: Quote from: tooki on April 07, 2023, 08:31:56 pmOkay I've made sure you can use fuses safely, as for not understanding what "9v available" means I've explained that if that's not enough at some point someone just needs to tell you that fucking off is an available option. You're being absurdly pedantic now.If you want to take up a terminology crusade go fight the RJ45/whatever battle for ethernet cables (yep I call them that, deal with it!)

author: floobydust
author_rank: Super Contributor
timestamp: April 09, 2023, 01:50:18 am
content: Don't blow a fuse. Apparently I am the only person measuring mA behind mains. This thread is full of know-it-alls that are spewing bullshit, but I don't need to fight or be mean.

author: tooki
author_rank: Super Contributor
timestamp: April 09, 2023, 04:23:36 pm
content: Quote from: py-bb on April 09, 2023, 01:46:26 amI asked for clarification, which is not the same as being pedantic. Despite claiming you did, you never replied at all until the response that includes a condescending snip pretending it’s some common usage, suggesting it’s me who should know better, when it most certainly is not accepted usage.You could have just said “oh, sorry, I just meant applying thousands of volts to a 250V fuse.”Quote from: py-bb on April 09, 2023, 01:46:26 amI call them Ethernet cables because that’s what everybody calls them. Itis“common parlance”. Saying that a load has a voltage “available” at its input most decidedly is not.

author: nightfire
author_rank: Frequent Contributor
timestamp: April 13, 2023, 06:26:48 pm
content: Got my replacement fuse today. Ordered a "Fluke" 44/100 Fuse and got a Bussmann DMM fuse delivered, no signs of Fluke stickers or so.Interesting fact: Ordered via Voelkner, got a plastic bag with some sticker that said "Distributed by Conrad" - big name here in germany.Best thing: Paid 10,70 € incl. sales tax for that little sucker ;-) (plus shipping, but I ordered some other stuff so i could put some rebate coupon to good use)Maybe helps other people in need of affordable replacement...

author: Greybeard
author_rank: Frequent Contributor
timestamp: April 14, 2023, 07:31:22 am
content: Voelkner and Conrad are the same company.Compare Voelkner and Conrad webstite: Voelkner is greenish, Conrad is blueish, parts are the same. But Voelkner is up to 50% cheaper for some parts, I compared a few years ago.