Is it normal for DMM replacement fuses to be this expensve?

[DimitriP]

So...what's the story with these guys ?
https://thefuseshop.com/products/bussmann-dmm-b-11

pack of 10 for $40 American

[floobydust]

Those are the old pre-greed priced parts. Watch out they could be "Bassmann" lol.
You do see "normal" pricing along with the asshat gouging on these fuses.
The crazy high pricing has led to fakes, counterfeit parts galore. Many youtube tests don't go well.
When I bitched to Eaton, they just told me to move up the sales chain - not pay retail but go for dealer or distributor cost.

I disagree with insulting people. They have no obligation to supply you at any price. They offer as they please and you are free to walk away and buy somewhere else. And if nobody else offers at a price you believe is fair then you are free to get rich by making them and selling them yourself.

Nobody owes you anything.

It's a safety item and other manufacturers have also decided to jack up their price. How is this good for the people?


Eaton Corp. bought Cooper Industries Bussmann 2012 for $11.8B and jacked up the (brand's) fuse price 10x of course. Gotta big loan to pay, new Lambo for the CEO, shareholders.  $138 for a cartridge fuse - assholes.

[ArdWar]

I usually just pre-blow all of my handheld DMM fuses and never replace them. Who uses them to measure current anyway

Benchtop DMM on the other hand are usually CATII and fuses are cheap as dirt.

[soldar]

It's a safety item and other manufacturers have also decided to jack up their price. How is this good for the people?

This is demagoguery plain and simple.

What's good for the people is to live in a society where there is freedom to buy and sell. If I am the owner of something I should be free to not sell or to ask whatever price I want even if others think the price is abusive. A free market has proved to be the best system to provide us, the people, with goods and services at a price that satisfies sellers and buyers.

If you find the price for those fuses too high you can buy at cheaper prices from their competitors or you can make your own or you can do without.

Again: nobody owes you anything. Nobody owes you fuses at any price.

[newbrain]

PS: I love how in multimeters that do 600mA full scale in the mA range (such as the BM867) they put a 440mA fuse. The first time i wanted to measure 500mA i got a nasty surprise 

Not to doubt your words, but this seems exceedingly strange, was it a very long measurement (hours or days)? Or maybe the average current was 500 mA, but with some initial heavy transient?

A fast 440 mA fuse will - according to the declared characteristic - withstand a 500 mA current practically forever, see the attached graph (from Littlefuse/Fluke, but I checked Bussman and some other brands, all the same, this is just the most readable).

[EPAIII]

This seems to be the same fuse, even with the Buss name on it:

https://www.digikey.com/en/products/detail/fluke-electronics/803293/1802030

It is listed as a Flute with a price of $12.62 each. And DK has over 3K of them in stock.

[EPAIII]

They may be a better investment than gold, silver, or any stock on the market.

So...what's the story with these guys ?
https://thefuseshop.com/products/bussmann-dmm-b-11

pack of 10 for $40 American

[tom66]

I liked those old Uni-T meters that used standard BS1362 plug top fuses in them.  Those fuses can interrupt 6kA (if genuine) and are suitable for most electronic and electrical applications short of three-phase industrial kit.  And if you are regularly probing around that kind of equipment, you can probably afford a more expensive fuse, or at least invest in a life insurance policy instead.

[indeterminate]

Its interesting that RS have them at $23.37

https://au.rs-online.com/web/p/multimeter-fuses/3012416

It defenetly pays to shop around.

[Red Squirrel]

The variation on the pricing of these really does seem weird.   I'm glad to report that I did replace it a while back and did not blow it again.   

[mag_therm]

Confusing fusing?
Defined levels
CAT 3:
   Three-Phase Distribution
   Some large building lighting systems and polyphase motors

Then, limits on multimeter use:
 
Cat 3 , 600 V : Source_Z= 2 Ohm, Is_c =300 Amp  : 1_ph. transformer (approx) : 12 kVA
Cat 3 , 300 V : Source_Z= 2 Ohm, Is_c =150 Amp  : 1_ph. transformer (approx) : 3 kVA

Maybe IEC needs to update ?.

[tooki]

Confusing fusing?
Defined levels
CAT 3:
   Three-Phase Distribution
   Some large building lighting systems and polyphase motors

Then, limits on multimeter use:
 
Cat 3 , 600 V : Source_Z= 2 Ohm, Is_c =300 Amp  : 1_ph. transformer (approx) : 12 kVA
Cat 3 , 300 V : Source_Z= 2 Ohm, Is_c =150 Amp  : 1_ph. transformer (approx) : 3 kVA

Maybe IEC needs to update ?.

Sorry, what does that have to do with DMM fuse pricing? And what exactly are you trying to illustrate with that anyway?

[rsjsouza]

Mouser has the "Fluke branded" 44/100 fuses for more reasonable prices than what is being mentioned in this thread. I might need to stock up on the 44/100...

Box with five for $34
https://mou.sr/3CIVdLE


Single for $13
https://mou.sr/3NeIZkj

[EPAIII]

Just an observation: the later models of the Simpson 260 have two fuses in series. There is a 500V, 2A and a 250V, 1A IN SERIES. I have had to replace the 250V, 1A fuse in more than one of these meters. I have NEVER, in my long career, had to replace the 500V, 2A fuse.

It seems to me that the 1A fuse is the one that blows first but it can only prevent arcing up to that 250V level. Only in the rare instances where higher Voltages are present does the 2A fuse blow and protect the user for the higher, 500V level. In fact most of these meters had an internal storage slot for a replacement 1A fuse but not for the 2A one because it was expected to last a lot longer.

The name brand fuses for the 1A position that Simpson specifies are quite reasonable in price while the 2A ones are considerably more expensive (but not as high as the $100+ fuses discussed above). This seems like a very sensible design. The less expensive part does most of the work and thereby protects the more expensive one most of the time.

Why couldn't the makers of the DMMs use a similar strategy with an inexpensive, lower amperage fuse in series with the more expensive, higher amperage and Voltage fuse in series?

Am I missing anything here? Other than a desire to sell expensive parts, that is.

[floobydust]

It was a short-term thing in the 1980's - multimeters using two fuses in series, the cheap one and the expensive one. Back then IEC 1010 was still in its infancy.

The fuse (blow) test that UL will do, it's very high energy to flush out a fuse that will explode due to the arc/heat (glass housing), or a fuse that catches fire or arcs to nearby stuff, or a fuse that never actually clears 100%, among many other things they test for.
So a cheap fuse will not clear properly with high voltage/energy, prone to explode and spray glass everywhere, arc that can move to nearby components inside the DMM or just across the fuse holder clips even, in the case of small fuses like 5x20mm.

These (big 38mm) DMM fuses have sand inside to quench the arc, Melamine high-temp housing- that is part of their extra cost.

[victorb]

I get the hesitation with the knockoffs on Amazon, you never really know what you're getting. Personally, I'd lean towards biting the bullet and going with the legit source just to be safe, especially since your DMM was a decent investment.

[Gyro]

It was a short-term thing in the 1980's - multimeters using two fuses in series, the cheap one and the expensive one. Back then IEC 1010 was still in its infancy.

The fuse (blow) test that UL will do, it's very high energy to flush out a fuse that will explode due to the arc/heat (glass housing), or a fuse that catches fire or arcs to nearby stuff, or a fuse that never actually clears 100%, among many other things they test for.
So a cheap fuse will not clear properly with high voltage/energy, prone to explode and spray glass everywhere, arc that can move to nearby components inside the DMM or just across the fuse holder clips even, in the case of small fuses like 5x20mm.

These (big 38mm) DMM fuses have sand inside to quench the arc, Melamine high-temp housing- that is part of their extra cost.

Yes, this arrangement was used for a while on Fluke DMMs, on the mA ranges. On my (physically bulletproof) Fluke 25, I was able to put an adhesive heatshrink sleeve over the body of the 250V ceramic (I'm not sure Fluke ever specified a glass) 630mA 20mm fuse to help retain any shrapnel. I bought a pack of fuses from a distributor and sacrificed one to ensure that they were sand filled.

I also found sufficient space to safely fit a 230V GDT (also heatshrinked) across the back of the 20mm fuse clip connections, the logic being that if the 20mm fuse opens at mains voltage, it will automatically be shunted, bringing the expensive 3A high energy fuse into action. This would also happen in the case of an unquenchable arc in the 20mm fuse (as fluke intended).

The later Fluke 27FM simply replaced the 20mm fuse position with a PCB track.

Whether these modifications make the meter safer is debatable, but as the Fluke 25 was pre-CAT ratings it is probably academic. Fluke proudly advertised that the case moldings were twice as thick as their other meters and it was also submersible to 1m, so I have a fair amount of confidence in using it in situations where I wouldn't risk something like a Uni-T. [EDIT: Not that I would be daft enough to knowingly measure current in a high energy circuit anyway!]

[wraper]

The fuses must be sold at wholesale prices instead, and some be included with the meters as standard accessories, to encourage people to use proper genuine fuses and not look elsewhere.

They're $11 and $6 each respectively if you buy 5-packs from a Fluke authorized distributor like Global Test Supply or TEquipment.  Anything much above that is silly, although there is plenty of silliness to be had.

Yes, there is some sort of insane grift going on with multimeter fuses if you try to buy them with fuse manufacturer part number (I suspect they prey on military or educational organizations). However exactly the same fuse sold under multimeter manufacturer part number makes them multiple times cheaper somehow, even though multimeter manufacturer certainly has their own markup in there. I've even seen that the same fuse series for non multimeter current ratings are way cheaper from the same distributor. Also SIBA fuses often go without insane markup https://www.tme.eu/en/details/5019906.11/fuses-10-3x38mm-super-fast/siba/ Otherwise buy Fluke, Brymen or whatever, in 99% of cases they'll be the same Bussmann, Littlefuse or SIBA.

[Stvor]

From EU, sites i trust:

https://www.welectron.com/Cooper-Bussmann-DMM-B-11A-HRC-Fuse-11A-1000V
https://eleshop.eu/multimeter-fuse-11a.html


https://www.welectron.com/Fuses
https://eleshop.eu/test-measure/meters/fuses.html

[EPAIII]

I don't know the date of it's manufacture, but I have closely examined one of my Simpson 260s (series 2). There is a separate compartment for the fuses and batteries. This compartment is molded of the same material as the main case of the meter, I would guess it is Bakelite. Both fuses are mounted in molded, vertical holes in the case. The 2A fuse is completely enclosed and the 1A is enclosed for about 75% of it's circumference but a slot in it would allow any fragments to enter the rest of the fuse and battery compartment.

And Simpson was very careful to state that a particular 1A fuse was to be used. They provided both manufacturer and part number. I have that, exact fuse in my 260s and can tell you that, while they are glass fuses, they are the 1.25"/31mm long AG3s which have at least 3/4" between the metal end caps. They also have a very small element that must limit the amount of gas or liquid metal that would fly about. I don't know what, if any amount of energy it would take to cause the glass outer envelope to be ruptured.

When you add the shielding from the case itself, it is hard to imagine that even with the largest possible "explosion" that the fragments of glass and metal would do any damage outside of the compartment. The inductance of the test leads themselves may be the limiting factor in any test or accident scenario.

To be honest, I can't recall any other meter that I have used or seen that had this much protection against an uncontrolled arc. My more modern (digital) meters and even other meters of the age of the 260s all have had far less insulation and just plain MASS between the input circuitry and the user. In many cases these meters that boast Cat III and Cat IV protection will have a thin plastic outer case and some internal precautions like slots in the PC board.

Again, just some observations I have made. It seems to me that, properly designed, the two fuse protection is fairly good. I do not know how these older meters would measure in an actual test. But then, I do not know just how well the testing procedure for these Cats have been designed.

I do know if I was taking measurements at a service entrance with heavy current capability I would feel safer with one of my Simpson 260s than with many of those Flutes with the Cat ratings. But that's just me. And I do know, from personal experience, that the 260 is not much protection from 40KV. But then, I seriously doubt that the Flutes would be either. Voltage and current protection are two different things.

It was a short-term thing in the 1980's - multimeters using two fuses in series, the cheap one and the expensive one. Back then IEC 1010 was still in its infancy.

The fuse (blow) test that UL will do, it's very high energy to flush out a fuse that will explode due to the arc/heat (glass housing), or a fuse that catches fire or arcs to nearby stuff, or a fuse that never actually clears 100%, among many other things they test for.
So a cheap fuse will not clear properly with high voltage/energy, prone to explode and spray glass everywhere, arc that can move to nearby components inside the DMM or just across the fuse holder clips even, in the case of small fuses like 5x20mm.

These (big 38mm) DMM fuses have sand inside to quench the arc, Melamine high-temp housing- that is part of their extra cost.

[floobydust]

Simpson 260-2 circa 1956 has no fuses.
Simpson 260-3 circa 1958, and the 4,5,6 and up have 1A 250V 3AG pigtail fuse.
260-7 circa 1981 and 8, 9 use two fuses in series, 1A 250V LF fast 312001 + 2A 600V LF BLS/Bussmann BBS 10*35mm big and ~$32 here.
The bakelite tunnel might be for the 5kV range? The 80MEG/4MEG 2W resistors?

I'll add those fuses are only for the meter, none for 10A current function. Like all my old manly multimeters, they have no fuse on the big shunt to prevent a lesson.

https://simpson260.com/downloads/downloads.htm