New Brymen BM2257 Multimeter

[Furna]

SIBA 7017240 comes in a 630mA SKU that should be an equivalent to the ASTM part:

  - SIBA 7017240.0,63 630mA 1000V  IR 30kA  (6 x 32mm)

  - https://www.tme.eu/en/details/zgssh-0.63a/fuses-6-3x32mm-super-fast/siba/7012540-0-63/  $3 each

For the 11A I am thinking this one DMM-B-11A https://www.welectron.com/mediafiles/datasheets/cooper-bussmann/Cooper-Bussmann_DMM-B_Datasheet.pdf

[mwb1100]

Yes, the 11A fuse in Brymen meters is the same as the Fluke 11A fuse - any Bussman DMM-11, DMM-B-11 or DMM-B-11-r will work.  Also the Littlefuse FLU011 or FLU 11A (I think any 11A Littlefuse with an ID that begins "FLU" will be interchangeable).  These fuses are generally easy to find, but seller's asking price varies widely.  You should be able to find one for around $10 or less without trouble, which looks like Welectron's price.

[Furna]

As soon as my BM2257 arrives, I will take it apart to honour the EEVBlog motto ... and if it really contains an Bussmann KLM-12 I will remove and sell it on EBay
It is 76€ on DigiKey.
That is ridiculos
 

[mwb1100]

[Bussman KLM-12] is 76€ on DigiKey.

Mouser is similar pricing...  everyone else is a more sane $10 each give or take (and I'm not convinced that they are fakes).  I'd bet that the Digikey/Mouser pricing is a mistake where they are quoting the boxed units of 10 as "Quantity 1".  Of course anyone ordering should confirm that with them and have the pricing fixed before ordering.

By the way, what makes you think the BM2257 might come with a KLM-12?  Dave's photos showed the ASTM HV110.

[Furna]

[Bussman KLM-12] is 76€ on DigiKey.

Mouser is similar pricing...  everyone else is a more sane $10 each give or take (and I'm not convinced that they are fakes).  I'd bet that the Digikey/Mouser pricing is a mistake where they are quoting the boxed units of 10 as "Quantity 1".  Of course anyone ordering should confirm that with them and have the pricing fixed before ordering.

By the way, what makes you think the BM2257 might come with a KLM-12?  Dave's photos showed the ASTM HV110.

I checked only DigiKey and Mouser ...
Pag 16 of the manual mentions Bussmann or ASTM (in this order).
I guess ASTM is cheaper than Bussmann so Braimen will use Bussmann only in case of shortages.

[mwb1100]

Pag 16 of the [BM2257] manual mentions Bussmann [KLM-12] or ASTM [HV110.11A] (in this order).

Interesting...  I didn't notice that when browsing the manual. Seems a little strange to specify the unusual Bussman KLM-12 (which is 12A/600V) instead of the DMM-11 which pretty much every handheld multimeter in this class uses.  The Bussman DMM-11 has the same specs as the ASTM H110.11A except that the IR rating of ASTM's is 30kA versus the DMM-11's 20kA (the KLM-12 has IR 50kA).

[EEVblog]

By the way, what makes you think the BM2257 might come with a KLM-12?  Dave's photos showed the ASTM HV110.

I checked only DigiKey and Mouser ...
Pag 16 of the manual mentions Bussmann or ASTM (in this order).
I guess ASTM is cheaper than Bussmann so Braimen will use Bussmann only in case of shortages.

My BM2257 stock has ASTM for both.
I'm the one that found and introduced Brymen to ASTM, they used to use SIBA. It seems that they may have now standardised on them, and yes, that would be because of cost. The ASTM's are very cost effective when you buy in bulk. I buy thousands at a time.

[EEVblog]

Limiting factor is the shunt resistor clamp-diodes, they must clear the fuse and never go open circuit.
Did you notice BM2257 they went overboard - five of 15A (350A 1/2 cycle surge) SMC parts - biggest diodes ever used there 
Not sure why Brymen upsized when everyone else has been using 1A (4007, M7) parts (Fluke, Agilent, BM235, 786, 857 and others) for many years.
It's great they are huge and safer, not likely to not care at all about clearing bigger fuses.

I suspect it's because they knew they were going for a bigger fuse rating for UL testing so they went full belt'n'braces to make sure. They are monsters.

[EEVblog]

Now it's got me wondering if I have to now stock two different fuses (400mA + 630mA) or standardise on either 400mA or 630mA for all meters (BM2257, BM235, BM786, 121GW) 

Obviously the 400mA will work in all, but the 630mA is technically not UL rated for the other meters apart from the BM2257, but of course in practice it will work just fine and be safe for all the 600mA range meters.

[mwb1100]

I buy thousands at a time.

Wow!

Now it's got me wondering if I have to now stock two different fuses (400mA + 630mA) or standardise on either 400mA or 630mA for all meters (BM2257, BM235, BM786, 121GW) 

Maybe change the package to:


    2 x HV110 11A 30kA 1000V HRC (10x38mm)
    2 x HV620 400mA 10kA* 1000V HRC (6x32mm)
    3 x HV620 630mA 10kA* 1000V HRC (6x32mm)

* the ASTM data sheet says H620 fuses are "Self-certified for Breaking Capacity 30kA @ 1000VAC/DC for 800mA and below"

The datasheet also doesn't mention a 630mA H620 fuse, but since Brymen is installing them I'm guessing it is available to the likes of someone who buys thousands.

I'd guess a package like that would make as many people happy as unhappy, making it a wash happinesswise.  People who want to go by-by-the book would be able to and would have a couple "not by-the-book" spares to get them by in a pinch if need be (or forever if they eased up).  No idea how much more trouble it'd be for you.

[EEVblog]

I'd guess a package like that would make as many people happy as unhappy, making it a wash happinesswise.  People who want to go by-by-the book would be able to and would have a couple "not by-the-book" spares to get them by in a pinch if need be (or forever if they eased up).  No idea how much more trouble it'd be for you.

It's trouble either way, guaranteed!
I think the mixed bag is probably a good idea.

[Kleinstein]

The 11 A fuse rarely blows. On the other side the 400/600 mA fuses may blow from time to time. They are really fast and I manged to blow one from inrush current to some electrolytic capacitors.

I would not mind the 600/630 mA difference very much, but the 400 mA fuse is still sufficiently different. It's the users to decide if they want a slightly more robust fuse or the original rating. Chances are it would be better to offer both sizes. There may also be owners of other meters that are looking for a spare fuse. I don't think a mixed bag would make much sense - one either wants the safe / certified way or the slightly more robust version. For those meters that specify 600 mA, very few would settle for a 400 mA fuse.

[EEVblog]

The 11 A fuse rarely blows. On the other side the 400/600 mA fuses may blow from time to time. They are really fast and I manged to blow one from inrush current to some electrolytic capacitors.

That's why my mixed bag has 2 x 11A and 5 x 400mA

I would not mind the 600/630 mA difference very much, but the 400 mA fuse is still sufficiently different. It's the users to decide if they want a slightly more robust fuse or the original rating. Chances are it would be better to offer both sizes. There may also be owners of other meters that are looking for a spare fuse. I don't think a mixed bag would make much sense - one either wants the safe / certified way or the slightly more robust version. For those meters that specify 600 mA, very few would settle for a 400 mA fuse.

Either way I've just ordered 1000 of both.
I might just offer two different mixed bags. Although I can see the emails now "you sent me the 400mA and I wanted the 600mA"

[mihaip]

Dave, when will you get new stock of BM2257 ?

[Fungus]

Pop quiz: How many mA does it take to blow a 400mA fuse?

[geralds]

Hi, I am new to electronics, and new to this forum - thus apologies if I am missing any convention (or if I am posting in the wrong thread).

I need a DMM for electronics repairs, primarily home electronics (laptops, hifi equipment, possibly some dehumidifiers, etc.). I have been looking at the BM2257, mainly because of the reviews and comments by Dave and others on this blog. Alternatives in my selection are AN870, ZT219, and H118E (though not my preference as they seem to be less solid and less accurate?). Or the Fluke 115 as a set with TLK-225-1 as this seems to be on promotion at the moment (but I understand functionality may be less than the BM2257?).

Against this backdrop / intended use, would the BM2257 be fit for purpose? Would you recommend another DMM? BM2257 is more or less top end of my intended budget. Fluke 115 cost more, but it already has the test lead set included (which I would need to add to the price of the BM2257 for a fair comparision). I would rather spend this money on the BM or the Fluke if the higher quality justifies when compared with the cheapos.

Many thanks for your help and input,
Gerald

[EEVblog]

Hi, I am new to electronics, and new to this forum - thus apologies if I am missing any convention (or if I am posting in the wrong thread).
I need a DMM for electronics repairs, primarily home electronics (laptops, hifi equipment, possibly some dehumidifiers, etc.). I have been looking at the BM2257, mainly because of the reviews and comments by Dave and others on this blog. Alternatives in my selection are AN870, ZT219, and H118E (though not my preference as they seem to be less solid and less accurate?). Or the Fluke 115 as a set with TLK-225-1 as this seems to be on promotion at the moment (but I understand functionality may be less than the BM2257?).
Against this backdrop / intended use, would the BM2257 be fit for purpose? Would you recommend another DMM? BM2257 is more or less top end of my intended budget. Fluke 115 cost more, but it already has the test lead set included (which I would need to add to the price of the BM2257 for a fair comparision). I would rather spend this money on the BM or the Fluke if the higher quality justifies when compared with the cheapos.

Welcome to the forum.
I might be biased, but the BM2257 is probably the most feature packed you will get the for the price in a top brand. Plenty for electronics and home repair. The Fluke 115 is an excellent meter, but doesn't have the handy EF function or TouchHold.
Both are plenty for home electronics and repair use.
THat being said, there might technically be better bang-per-buck to be had in the lower priced tools like the AN870, which would also suit your purpose.
https://www.eevblog.com/forum/testgear/looking-at-three-very-different-multimeters-(aneng-an870-and-eevblogs-meters)/
You can get cheap probe adapters of various sorts from Aliexpress if you need those. e.g.
https://youtu.be/tz4cYPj3Kls?si=LWfqDO8283CIK-V7&t=864

[mwb1100]

I have been looking at the BM2257, mainly because of the reviews and comments by Dave and others on this blog.

The BM2257 is very newly released.  As far as I know it hasn't been reviewed by anyone, more or less just comparisons of the specs and build when compared to the BM235 (and to a lesser extent the BM257s).  It's expected that the BM2257 will  perform and have a robustness similar to the BM235/BM257s.  I believe it has all of the features of the BM235 and the BM257s plus more.  The specs are very similar, but there are some differences - minor ones in my opinion.

Probably the biggest features over the BM235 are PC connectivity, which requires an additional purchase of a interface cable, (the BM257s also had PC connectivity) and autohold.

The BM2257 look like it will cost about $25 - $40 more than BM235. I think the consensus is that the BM235 is considered a pretty good value considering design and build quality and feature set.  I'd expect the BM2257 to be similarly regarded, but that's just my expectation, but it is at a higher price point.

The Fluke 115 looks to have a similar feature set to the BM235 (i haven't done a point-by-point analysis of the datasheets though), but costs more than twice as much.

The other meters you mention are significantly less expensive, and are probably a better way to go when starting out.  After using them for a while you'll have a much better idea of what you might be willing to pay  more for. They should be pretty darn accurate, where they might be lacking is in robustness and safety.  For electronic work those aren't too much an issue, for mains work opinions differ.

[EEVblog]

Pop quiz: How many mA does it take to blow a 400mA fuse?

In theory, 401mA after quite some time.
At 400mA the fuse should not break after an infinite time.
In practice, any random value if you bought a fake off ebay, or if genuine follow the parametric charts and add your own window, add salt to flavour.

[EEVblog]

Dave, when will you get new stock of BM2257 ?

Stock keeping error, I have them, check again.

[Furna]

Dave, when will you get new stock of BM2257 ?

Gemini:
A 400mA fuse is designed to blow when the current flowing through it exceeds 400 milliamperes (mA).

**Therefore, it takes slightly more than 400mA to blow a 400mA fuse.**

* **Note:** The exact current required to blow the fuse can vary slightly depending on factors like the fuse's specific design, age, and operating temperature.

[mwb1100]

Pop quiz: How many mA does it take to blow a 400mA fuse?

Depends on the fuse.

According to this datasheet for the SIBA 7017240, a fuse which has been used in Brymen meters and other fast blow ceramic fuses used in meters might be similar to:

  - at 400mA the fuse will last at least 1 hour, but could (and should) last much longer
  - at 1.6A the fuse will blow within  60 ms
  - at  4A the fuse will blow within 6 ms

(assuming I'm reading the table and chart correctly)

[bdunham7]

I need a DMM for electronics repairs, primarily home electronics (laptops, hifi equipment, possibly some dehumidifiers, etc.). I have been looking at the BM2257, mainly because of the reviews and comments by Dave and others on this blog. Alternatives in my selection are AN870, ZT219, and H118E (though not my preference as they seem to be less solid and less accurate?). Or the Fluke 115 as a set with TLK-225-1 as this seems to be on promotion at the moment (but I understand functionality may be less than the BM2257?).

If your budget allows it, avoid the low-end stuff.  Either the Fluke or Brymen will be good. 

What is the promotion Fluke is offering? Fluke stuff is expensive, especially in Europe so waiting for a sale is wise. I'd actually recommend you look at the 116 plus maybe a current clamp.  A while back I got such a set on promotion with a pretty good set of leads, case, etc.  It might seem strange not having a current range, but since the 115 only has a 10A range anyway I don't think you're losing much.  You don't want to be running mains current through the meter like that.  Since you say you're a novice, the 116 has the advantage that it is literally impossible to blow it up by connecting it wrong to any voltage you'll find in your household--except the microwave oven and please don't ever open that up if you don't know exactly what you are doing (and best not even then).  The 116 and BM2257 also have a Low-Z mode that you may not understand at the moment but is IMO a very valuable feature.

If you want good test leads, look at ProbeMaster.  Also, I believe if you buy the Brymen BM2257 from the EEVBlog store you get some pretty good test leads in the package.  The TLK-225 set is nice stuff, but geared more towards industrial electricians.  I have some of those probes and clamps and don't use them all that often.  It seems a bit odd to offer them with the 115 because they're more something you'd use with a 179, 87-V or 287 since those are CATIII/1000V meters. 

[tautech]

Pop quiz: How many mA does it take to blow a 400mA fuse?

In theory, 401mA after quite some time.
At 400mA the fuse should not break after an infinite time.
In practice, any random value if you bought a fake off ebay, or if genuine follow the parametric charts and add your own window, add salt to flavour.

Good topic for a video.

Quality vs no name vs Normal vs Slow blow vs Fast blow.
 

[EEVblog]

Pop quiz: How many mA does it take to blow a 400mA fuse?

In theory, 401mA after quite some time.
At 400mA the fuse should not break after an infinite time.
In practice, any random value if you bought a fake off ebay, or if genuine follow the parametric charts and add your own window, add salt to flavour.

Good topic for a video.
Quality vs no name vs Normal vs Slow blow vs Fast blow.

It would be, except it's basically a statistical thing, so you have to run a lot of them.