Fluke fake multimeter fuse WARNING!

[cowboy]

I wanted to call attention to something that many of you already realize, but many other folks are unaware of.

This concerns the Bussmann, Littelfuse and other OEM fuses for Fluke meters.

I will use an an example of the two most common fuses for Fluke meters, the ones used on the Fluke 83, 85, 87 series and many other models.

These fast-acting Bussmann fuses (11A and 0.44A) are about US$34 each at retail, however Fluke has a special pricing on these fuses for Fluke owners of $9.30 and $7.00 respectively through Fluke distributors such as Digikey, Mouser, etc. - This is what the Fluke corporation pays for these fuses direct from Cooper Industries- Bussman, in lots of many 1000's of fuses, they don't mark them up over their wholesale cost in order to encourage people to use the correct fuses for their precious Fluke meter.

When you see these fuses on ebay or other websites for $3.50 or $5 or something like that, these are Chinese COUNTERFEIT Bussmann fuses and could easily endanger your expensive meter at best, or even start a fire and endanger your life at worse.  The real genuine ones are not even made in China, they are made in Mexico (and the fakes are also marked Mexico) You think you are going to buy them in lots of one or two cheaper than Fluke buys a tractor trailer truck load for? wake up!  It doesn't matter what country the seller is in, or what the fuse looks like, it's fake!


Example auctions:

http://www.ebay.com/itm/Bussmann-DMM-B-11A-1000V-DMM-11A-Multimeter-Fuse-for-Fluke-87-V-88-V-287-289-179-/261536107575
http://www.ebay.com/itm/Fluke-11A-1000V-DMM-11-A-Digital-Multimeter-Fuse-87-V-88-V-287-289-179-US-SELLER-/161104330017

regardless of what the price is, or what the photo looks like, buying fuses on ebay is a bad plan, just like with capacitors, 99%+ of the auctions are of very crafty done fakes.  Ebay is better suited to finding that great piece of vintage HP or Keithley or Fluke or Tektronix test equipment, NOT fake fuses and caps!


I am all about living frugal, but this is one place where you want to stick with authorized sources, and a great discount from Fluke, or you could pay dearly!

[P90]

I've always thought Fluke fuses are way overpriced, a rippoff actually. I'm almost afraid to measure current on my meters for fear of blowing a $10 fuse... lol

[RoGeorge]

Is there any proof they are fake, other then the price difference?

$34 for a fuse! 

[Vgkid]

I know fluke did offer a 5 pack of fuses for about $25.

[Whales]

For end users: having fake fuses is not the direct issue, it's whether or not they provide the same level of protection.

I don't have any Fluke's or Flukey fuses, but I did notice that cheap and brand name fuses seem to have different innards.  I think the sand is there to help quench the fuse faster, but I'm not sure.

Cowboy: could you crack open a fake and a real fuse and show us the differences?

[Jeroen3]

Maybe photonicinduction should test some.

[RoGeorge]

If one gets electrocuted for using fake fuse

AFAIK this kind of fuses are to protect the equipment and/or to protect against fire hazard at most. They can not save people from electrocution. It is hard to imagine how someone might die because of a Fluke with a cheaper 10A fuse, but there is no thing such 'idiot-proof' so it might be possible somehow.

Still, I totally agree with you to order the expensive ones for somebody else, and I will probably do the same. The psychological comfort may worth more then $30, especially if the $30 are not from my pocket. Marketing people certainly noticed that too, so I bet this is the main reason for a piece of wire in ceramic tube to be sold at the price of an average DMM. For personal use I will order the cheaper ones, because I see no real benefit from the expensive fuses.

[CJay]

That's not that simple. A proper HRC (high rupture capacity) fuse is designed so that in case of a high voltage high energy dead short, the fusing element will break at several points, rather than a single point, so internal arcing possibility is minimized. Quartz sand inside cools down the hot plasma so it also helps extinguishing the arc.
Finally, the casing of a high quality DMM fuse is epoxy soaked fiber glass on top of ceramic tube, not just a single layer of ceramic tube. In case of a short circuit, high pressure generated from quick evaporation of internal fusing element and heated air may explode the ceramic tube, but the pressure and shrapnel will be contained by the outer epoxy fiber glass layer. This prevents your DMM from exploding in your hand.

Bulletproof fuses essentially.

I've seen the shrapnel of ceramic fuses embedded in the inner case of an ancient television, it's amusing until you realise that could have happened with your eye, I would definitely prefer my multimeter to have the correct fuse even though I am highly unlikely to approach the energy ratings (there was an unfortunate incident with a 'scope tube EHT supply but that's rather embarassing and for another time)

[cowboy]

The point is - if Fluke will give you the very high quality $35 fuse for $7 or $9 depending on which one, why would you risk a $500 meter or a fire or whatever in order to save $4 on a fuse that rarely, if ever, will need to be replaced? - It's crazy.

[wraper]

The price is definitely feasible in China. I just did a search on a number of Chinese sellers, and it seems like $2.5 is a reasonable price. Some sellers even showed their formal invoice for these goods and some showed original package and import documents.

A lot of counterfeit things are sold in "original" packaging. Some eevblog members bought multimeter fuses from China and they were fake.

[wraper]

The price is definitely feasible in China. I just did a search on a number of Chinese sellers, and it seems like $2.5 is a reasonable price. Some sellers even showed their formal invoice for these goods and some showed original package and import documents.

A lot of counterfeit things are sold in "original" packaging. Some eevblog members bought multimeter fuses from China and they were fake.

It could be many sellers selling fake, but it is impossible to see all sellers sell fake.
All search results show ~$2.5 price range.

Why not, if all of you are looking is in the same price range.

[Zbig]

The point is - if Fluke will give you the very high quality $35 fuse for $7 or $9 depending on which one, why would you risk a $500 meter or a fire or whatever in order to save $4 on a fuse that rarely, if ever, will need to be replaced? - It's crazy.

Get real, it's not a "$35 fuse" and never was. That someone tries to charge you that much for it - well, that's a whole different story.

[oldway]

I think it's more an academic debate than anything. 

The danger with these fake fuses only exists when measuring on high energy circuits.

First, this is not the majority of users.

Next, industrial electricity and power electronics are disciplines where technicians/engineers must have the proper training.

This is my area, I know of what I am speaking about.

1) NEVER measure a current on high-energy circuit with a multimeter, always with a current clamp. 

2) we always check and recheck before making a measure ... the possibility of error or distraction is excluded.

3) an industrial electrician / power electronics engineer use his multimeter WITHOUT FUSE for safety 

To measure the voltage of a busbar 5000A 550Vcc is not done without extreme précautions because even the original fuse will probably not interrupt such a high DC voltage with high energy.

[Jeroen3]

1) Sometimes you're an idiot and measure Volts while the meter is connected in Amps. Flukes will beep at you. But you won't hear that in all use cases. ^{This will cause a plant-wide blackout when you're fixing the 10kV load sharing.}
2) When you're doing repeated work. This will be a point of mistakes.
3) He doesn't have a multimeter. He has an Voltage Tester. Such as an Fluke T90.

Sometimes you have to measure busbars, but you don't do this on the live busbars unless you can't possibly do it elsewhere. Often, busbars are near some kind of cabinet with control and/or measure electronics, and you can measure after the fuses or mcb.

[Neilm]

I've seen the shrapnel of ceramic fuses embedded in the inner case of an ancient television,

I did a test where we put very cheap multi-meter which had a glass fuse across a 440V supply (the meter was rated for 600V). I found part of the meter case on the other side of the room. We drew enough current to trip the 75A breaker.

[saturation]

You should buy your fuses from an authorized distributor because counterfeit is so abundant.  Not just Fluke DMM, but also automotive, and anything where safety is paramount; for cheaper fuses you can destructively sample test fuses to insure its to spec.

http://www.cooperindustries.com/content/dam/public/bussmann/Electrical/Resources/product-datasheets-a/Bus_Ele_DS_1047_DMM-B.pdf

For DMM fuses, you have quite a margin for error before they blow.  To save money get the Bussman brand, not Fluke [ they are made by Bussman anyway], they are about $7-10 each or less.

[joeqsmith]

This subject came up not too long ago.  I would not mind getting some known counterfeit HRC fuses from a few different sources.  The 440mA were about $5.00/ea from Digikey last time I bought them.  $10 for the higher current.   

I wonder what is worse, replacing a blown fuse with a counterfeit or jumping it out with some magnet wire.  At least with the wire, you're just being stupid.  With the counterfeit you may have just been scammed is all.   The end result may be the same.     

[BravoV]

For personal use I will order the cheaper ones, because I see no real benefit from the expensive fuses.

Yeah, right, better alternatives too for your reference ... 

[P90]

I recently purchased a Fluke 88 used for $25, and when I opened it up to fix the LCD ghosting issue, I found both fuses blown. Some genius had wrapped aluminum foil from a gum wrapper around the blown 15Amp fuse. I wish I took a picture to post...

[BMack]

Buy the fuses from Authorized dealers. $10 for a fuse isn't that bad unless you're blowing them all the time...and if you're blowing your DMM's fuse a lot your problem isn't with the fuse price, it's the thing holding onto the leads that's the problem.

[P90]

Buy the fuses from Authorized dealers. $10 for a fuse isn't that bad unless you're blowing them all the time...and if you're blowing your DMM's fuse a lot your problem isn't with the fuse price,     


it's the thing holding onto the leads that's the problem.

[george graves]

I wanted to thank the OP for the link.  I never measure high voltage/energy with my precious fluke. But I do have a brain fart once in a while and forget to switch the leads.

I'll have to order some of these! 

 

[joeqsmith]

I think I may have acquired some fake SIBA branded fuses.  I was thinking to make some sort of video comparing what I believe is a real one showing the following:

Non-destructive:
markings
length
weight
DC resistance
voltage drop at max current
case temperature at max current

Destructive
trip current
check filler

[Fungus]

I think I may have acquired some fake SIBA branded fuses.  I was thinking to make some sort of video comparing what I believe is a real one showing the following:

I bought some SIBA fuses on eBay recently for an old Fluke I picked up for $20.

I'm not intending to use the meter on AC mains but it would be interesting to know if the fuses are fake. 

[EEVblog]

I'm now selling genuine ASTM fuses in a mixed pack.