Bad Fuses 

Thanks for sharing this. This is taking slow-blow fuses to a new level... never-blow. I have a box of no-name fuses too and will be getting rid of them.

Glad you did this test. I had always assumed off brand fuses woukd be at least close to thier rating. Thank you.

This is not the first time I have seen this style of demonstration. I was amazed at the data that the demonstration produced. Essentially the same outcome as your test, but lacking your sophistication. I was staying at a friends house several years ago, & I was given a spare room in their home to spend a night with them. This room was awaiting a contractor to tear out the ceiling & walls & install first grade insulation & such other work as he deemed necessary to make the room cozy in the coming winter. My friend had purchased an electric heater (1500 watts) & it was plugged into a wall socket that was a dedicated 20 amp circuit. About an hour after retiring I awoke because of an odd smell. I sat up in bed & the electrical heater was engulfed in flames, & the power cord was burning along its length. One door in the room opened into the house proper, & the other opened into the back yard. I had left my jacket , trousers & outside boots beside the bed . I turned on the night table lamp, pulled my boots on & grabbed my coat & removed my leather gloves(work style, not "dressy" style), grabbed the handle of the heater (which was already starting to melt) , opened the outside door & heaved the heater into the yard, & then turned & pulled the power cord from the wall socket, & threw it into the yard. The rug was on fire, but it was a material that was very slow burning ( treated as "fire retardant"" & it joined the rest of the immolation in the yard. The next door neighbor saw the flames & ran into the back yard with a CO2 extinguisher & snuffed the burning bits out. My friend ran 9into the rook & did the same to the rug & we opened the two windows in the room to lose the smoke. Another neighbor had summoned the fire dept. & they & the police arrived together. The Captain declared the fire officially out (a second co2 bottle was used & they made certain the flooring beneath the rug & the wire & wood behind the melted outlet was flame free. The fire Captain said that the Provincial Fire Marshall's office was attempting to have that particular heater banned from sale. The next day we bought a new 20 amp duplex receptacle, & I installed it . The lady of the house plugged a floor lamp into it, & turned the light on & all appeared well. I went to close the door on the entrance panel , & noticed that the dedicated breaker was open, but the light was still on ! I reset the breaker, & it was not latching. I removed the floor plate on the breaker board & removed the 20 amp breaker & took it apart, to find the contacts were welded shut !! My friend asked me what I thought. I told him that I thought that he should call a Provincially licensed contractor & have him examine the panel installation, & anything else he deemed necessary, & to give you a report. The panel was made in China, & all its internals were as well. Most of the wiring had to be changed as well. My friend engaged his insurance company at this point, because his sister from whom he had purchased the house & who had paid a local electrical contractor to upgrade the house from a 60 amp circuit to a two hundred amp service, & it ALL had to be removed & approved equipment installed at great expense. You never know these days.

I go to a generally recognized national auto parts store for my fuses (I generally use Bussman). The price difference between the better fuses and the generic ones is pretty minimal compared to the value the better ones provide, in the larger picture. Nice video.

Very interesting I'm a mechanic and I didn't know that all fuses were not created equal I will no longer be buying cheap fuses Thank you

I'm building a van and you just scared the crap out of me!!! I just order 2 big boxes of Littlefuse blades. Thank you so much.

Those fuses are nothing more than pretty plastic covered nails.

Thanks for the heads up on these fuses. I have a bunch of these fuses in a box and a few in service. I will now toss all of them.

Those no-name fuses can come in handy since it would be difficult to get a penny in that blade fuse holder.

Thank you very, very much for this video. As a motorhome owner this is very worrying as I have been using those cheap fuses for years. I have been very lucky. I am buying a set of decent ones straight away and replacing them all. Thanks again.

Discovered the same thing about 10-12 years ago when a cheap fuse from one of those kits failed to blow when a wire shorted to ground on a motorcycle. The end result was a small fire and many hours of labor replacing the bike's wiring harness. I contacted the seller and let them know what happened; they didn't believe me. Testing the fuses found the same thing as in this video, they just didn't open under 2x-3x their rated load.

Thanks for the eye opening information. I've always used Littlefuse and Bussman fuses whenever possible, but now I'll stay with them all the time.

Thank you for doing this and sharing it. I have for years used any old fuse I could find (correct stated rating though). I will avoid noname fuses from here on out! Shocking results.

You've created some work for me with this video... Thank you.

Fuse wire is made from a special metal alloy wire that will fuse(When any wire melts open, it is said to fuse) that is suspended between the mounting connections hence the added value.The giant bag of fuses for a dollar that I have inspected seem like the fuse wire in them is just part of the stamped out aluminium mounting blades hence no value. Great video N0̷PXJ

Great video! Excellent warning about cheap fuses that often get taken for granted. Please note though, that those types of heat guns observe a rather large conical region in front of them to determine the temp. They do NOT measure the point at the red laser dot. Unless one is measuring a larger area (like a frying pan for example), they are inaccurate for small spot measurements like the fuse - the fuse is likely to be much hotter than one it displays since it is averaging same of the desktop temp with the fuse. Nonetheless, awesome video. Will be sharing this with others!

I'm most impressed! Very important info. Now I got to go check my fuses. Don't forget to check what goes in your car, lots of sensitive stuff in there.

Tanks Tom another really informative video. Look forward to more in the future.

I was randomly recommended this video and straight up bought spare bussman fuses (the littelfuse kits were about the same price) just now. Glad I never had to use the spares I bought a couple years ago, those will go straight to the trash. It seems like the knockoff kits spent all of their money on a case so maybe I'll put the good bussman fuses in that. Thanks!

Hi, Tom. Thanks for the very informative and interesting video. Blade fuses are a type of commodity item I've never really thought twice about. I guess not all of them "just work". I'd hate to have one of those 5A no-name fuses "protecting" a sensitive circuit in my vehicle. Well done. Marc (N1QGM)

These fuses are the best kind! All the other ones blow out so fast! This is the last fuse you will ever need to buy.

Great job! Sometimes a return to basic component information is invaluable. I think another component that needs examination is clone Anderson Power Points. Many of them look right, but do not use the proper materials and arc at very low currents! Hope you'll do more things like this....

I bought a similar pack of bargain fuses, and had some suspicion, based on the thickness of the internal conductor, that their rating was off. You just verified what I suspected, in a rather dramatic and more accurate fashion. Thanks!

Extremely helpful video! I've got a package of Bussman fuses on order and am going to swap out all my current no-name blades as soon as it arrives. Never thought about fuses before and just assumed a fuse is a fuse is a fuse. Thank you so much for this informative video! 73!

I ditched the cheap fuses not over the (unknown to me) failure to blow, but rather over their inconsistent thickness and inability to reliably make contact with sockets. Many off brand fuses are some random pot metal that doesn't seem to fit correctly, and have all sorts of strange geometry on the legs that you push into the sockets, compared to the Bussman, LittleFuse, and other OEM fuses that all fit snugly and have well formed connection legs.

Thanks Tom,really good info. Never gave it a thought till now will check my that hang on wall. Thanks again.

This is a great bit of advice, and a nice catch. I can only imagine how many of these no-name kits have been sold, and how many devices out there are virtually unprotected due to the use of imposter fuses! As another viewer commented, some of the dirt-cheap fuses are made with some rather dubious metals that rust/corrode, and that's a deal-breaker in and of itself! I'm not in the radio field, my interests lean more towards automotive and computers, but I've always used Littelfuse or Bussmann - leaning more towards Bussmann as the fuse bodies are more translucent and easier to see gaps. I feel more comfortable with a brand I've used for years, over some brand I've never heard of that has so many vowels that I'm not exactly sure how to pronounce it. The price differential isn't significant enough for me to "go cheap." Sometimes you really do get what you pay for! When I first saw the 5-Amp in your test rig on the bench, my initial thought was "that link is WAAYYY too thick to be a fiver..." At a glance, it looks like a 20-Amp or 25-Amp. I know what some of you are probably shouting at your screen right now: "you can't properly rate a fuse based on looks alone," and generally speaking, yes, you're absolutely right and I wholeheartedly agree. BUT this fuse was CLEARLY not a 5-Amp, heck, it's more like a fuse-shaped link! As you so handily demonstrated, it could easily withstand multiple long-run tests at 400% rated current. I've seen heat-warped fuse blocks once in a while, in cars that I've repaired over the years. I think you might have solved the mystery for how that happens - OEM fuses pop and some "El Cheapo" fuses the owner bought shoved in to replace them. I watch a few HVACR channels, and most RTU (rooftop units) use a 5-Amp blade fuse to protect the control boards. I might drop a note with those Creators and suggest they buy Bussmann or Littelfuse exclusively. I assume they do, since they go through commercial warehouses, but they've got businesses to run and might consider trimming overhead by buying bulk no-names.

Tom, this is great data. Will spread the word to the club.

Thank you for sharing your testing, something I had not been considering a potential issue. I will examine and replace all my fuses now as well.

just this week I had smoke come out from under the dashboard of my car , 2 wires dead shorted and went red hot , burnt all the outer covering to a crisp , they where supposed to be protected by a 10 amp fuse , all that the fuse did was melt a little bit , but did not blow. I think the cars battery is a 60 amp. I will be replacing all the cheap fuses with brand names asap. thanks for your video.

I bought some Blue Sea circuit breakers and tested them. There were many amps over the rating and several minutes to pop. They are very slow to go and their tolerance is very high. Good info.

Thank you for testing these fuses, and for making this video!

Nice video. And also a very important topic. These cheap "dummy-fuses" won#t save you a penny, if your car or even your house catches fire and burns to ashes. But, just for showing the seriousness of the danger (and for fun), you should have used thinner wire, that actually melts or lights up. Anyway, amazing video, thank you. 73s

Thanks for taking the time to share this information! Before throwing them out, maybe test them on a car battery in various parallel configurations. Then maybe you can repurpose the 5A fuses to protect 00 wire...😛

Just shocking. Never thought the China fuses were that far off , it’s simply so dangerous that the companies that put them up for sale should be sued. Thanks for an interesting test.

Wow! You're right, thanks for testing these. I have a box of no name fuses also, I just tested several 5 amp fuses on a quality 20 amp power supply - they didn't blow, I even tested the ten amp fuses.

Ok, you've spooked me! I like littelfuse but have some cheapo genetics. Ordering replacements now. Thank you!

I discovered this a while ago, After having to re wire the loom on a friends Quadbike, I tested the 45A at 60A and it melted the plastic but didn't blow. Lawson Fuses are the best.

I'd of never thought that no name fuses would be THAT bad! I think I have some and will check them and probably through them out. Thanks for making this video. I too am a Ham Radio guy.

In the UK, I have found those "cheap and nasty" fuses have blades made of aluminum 0.5mm thick. The decent fuses have blades made of nickel plated brass, 0.7mm thick. So there is potential for the cheap fuses to give a bad contact. I once made sure I gave eveyone in my car club a "free fuse" and told them that if you can easily bend the blades like you can on your free gift, don't buy it...

The fuses that are hard to read, don't have the rating colored white, are the ones that are not "certified " as I understand. I found a video similar to yours stating this. I trashed my assortment from Harbor Freight, and purchased a Littelfuse assortment. Great video

Thanks for a superb video and useful warning. I'm a glider pilot and use this type of fuse to protect the wiring that runs under my seat; I can't remember where I bought them. I must figure out how to control the current from a lead-acid battery so I can check one or two of mine!

This information is soo needed. This was 101 in my day. Trust but verify… especially when expensive equipment is involved.

For 44 years, I taught aircraft electrical/avionics/weapons control systems maintenance. I do not remember one new student knowing the true purpose of fuses/circuit breakers. When we got done, they knew.

Thank you so much !!! You are seriously saving things and people with this.

One thing you'll also find with the cheap generic no noame fuses is the blade material is thinner, therefore it doesn't have the same contact pressure and that allows resistance and heat build up. I've seen a few of thses melt in the past. I'd also check the temperature of the powerpole connectors as they are rubbish, I refuse to use them. Very disconcerting that the 5A fuse just doesn't blow at 20A though, so generally zero protection and 100% dangerous.

About that fire extinguisher - you might want to get one with metal handles. I've heard stories about the plastic ones breaking during test. (Especially if you fail to properly remove the safety.) They're a little more expensive and a bit bigger, but still a good investment.

Wow! I'm not a radio guy but really appreciate YT for suggesting this video. I recently bought one of those cheap fuse kits on Amazon to keep in my RV. Not only will I toss that kit out but I'm going to have to go through all the fuses in my coach because I've a bad feeling that the manufacturer of my RV may have used these cheap fuses. I can only wonder how many camper fires might have been caused by one of these poorly made fuses. Thanks!!!

I was concerned about this exact issue, so I didn't get one from amazon. Thanks for confirming my concern.

You have illustrated overcurrent protection in the precise way it is intended to work. The startling issue I had not expected is the lack of specification on the chinesium fuses. Very nicely done and an important warning.TNX

I had some of these no name ones in our Peterbilt fuse panels until we found out some of them would actually catch the plastic on the fuse on fire and still not blow the fuse! Never again.

Did not realize this about fuses. Will be checking what kind of fuses I have. Thanks

Thanks I'm changing my fuses today!

Great knowledge. I` m going to check all my DC fuses in our RV.

Had always assumed a fuse was a fuse, and even though I have a couple kits of brand-name fuses, I also have probably that exact same kit of generic fuses. Throwing it out. Thanks!

I have several of these boxes and DID get an expected clear on fuses below 5amps. I need to test them and also would have liked to see you text the bigger no names. Guess I need to price out name brand on fuses boxes and test my cheapies

Well I’m about to order some new name brand fuses and throw out all the no brand stuff on my bench right now. Thanks Tom!

Thanks for sharing this. I always say that government has a function. One of those functions is to protect consumers. When safety devices fail to do their job, the government should prohibit their sale as a risk to safety. My only concern with your test is you showed only one test of a 5 amp fuse. I'd like to see the results of 5-5 amp, 5-10 amp, and 5 -15 amp fuses. Certifications are important. But even without them any safety device should perform as expected or be prohibited from sale.

Excellent and informative video! Time to double check my fuses!! Subscribed!!

That was a great test! Very useful.

Thank you for this video! I had cheap fuses laying around and tested them, this is what i found: 1. 3A fuses did not blow at 10 amps even after 3 minutes 2. My switching-mode power supply blew a couple of 2A fuses at

Wow, thanks for sharing this information and I am glad to have seen this video. I'll share this with my friends.

Just WOW. That’s great content. Good job.

Afterwards Happy 4th of July, Tom. Good to see you back again.. 73 de Uncle Günter 💯👌🙋‍♂

Excellent video, thanx for the warning. I did buy a non-branded kit "ABN". Tested the kit on my PSU and the fuses up to 20A cleared in a timely manner. Looks like the fuses you had were just bits of wire between the lugs... Thanks again.

... some months ago i had my fuse box melt down while i was driving, and i had no idea how the heck it happened. looks like i might have just found out.. ty so much, i am gonna go grab some bussmann resettables and pray they're authentic i think XD

Thanks Tom. Great info

There was a massive recall of these fuses a few years ago, because the only difference between the fuses was the colour of the body, as they all used the same stamped out fuse element, and simply put a different colour body on the top. Millions of boxes recalled, they had to go somewhere, so likely got sold off as lots cheap. Basically look at the elements, if they are all the same size they are all 30A fuses.

Very revealing! Thank you! And to think some amateur airplane builders might use these cheap bad fuses as their circuit breakers!!

Great subject, Thank you, I had suspected this, you proved it. Thanks from N8AGW

I have some no name fuses and no longer use them. One was melting, turning black, smoking, and almost caught fire after running at capacity for a long period of time.

Thanks for the chart, one more data point, typically those chinese fuses are aluminum, and aluminum on standard tinned brass terminals is a corrosion and fire hazard when exposed to wet environments. I had a piece of outdoor equipment, 30a fuse for the glow plugs ended up burning up the whole fuse block. clipping one fuse leg will show if its tinned brass or aluminum. Buss fuses are a guarantee to be tinned brass

Nicely done!

A very good demonstration and an eye-opener to modern day equipment. I have very little new equipment as I am a homebrewer and operate boat-anchor vacuum tube equipment. The fact that the voltage on the power supply drops to 0.6 volts and still maintains 20A is amazing to me. That is 12 watts of heat being dissipated in the fuse, as your temperature measurements indicated, which seems like it would melt the fuse link in a reasonably short time. Apparently not... My power supplies are all the linear brute-force type and shorting one of them will likely not drop the voltage any significant amount so we would end up with the full 15 volts (as in your example) at 20A for 300 watts being dissipated in the fuse and we all know where that is going to go and hopefully the fuse will protect the equipment from catastrophic damage and possible fire. With over-current sensing in SMPS in modern equipment, it almost seems redundant to put a fuse in the output side, although I think it is still a good idea. 73 WA4QGA

Great video.. I was just mentioning to my brother a few days ago not to buy no-name fuses and to stick bussmann, etc. For individual fuses, I usually purchase them from digikey or mouser to be safe.

Outstanding video and demonstration. Thanks for sharing this. 73’s N2STX

I was reminded long long long ago that my auto instructor said you're paying for the metal they use for these fuses, & they were coming from a place of experience.

I had some of these fuses around and used them once for some relays, a fan they were controlling got jammed and it should have blown the fuse but instead melted all the plastic off of the fuse and got everything pretty hot. I bought a box of legitimate brand fuses and made sure that I never used the cheap ones again.

Thanks for the information about fuses.

I had that cheap chinese fuse kit. After seeing your video 2 months ago i threw them all out and bought all Bussman. I did use the chinese plastic case.

Excellent advice based on your tests!

great video and a solid reminder to ALWAYS buy name brand fuses that specifically list the specs and have the UL seal of approval. Remember... you get what you pay for.

Thanks for the heads up!

Thanks for the tests. Just 2 comments, it could be sped up only, mentioned twice sloowly the ebay amazon (we got it the first time around! ;)). Second thing the mic scratching can be painful after a while. I hope it will help make your next viseo even better!

Thanks for the enlightment!

Thanks for a great video!

Thank you very much, I have same that unbranded fuse and I tested them my self... man they are unblown able ☠️☠️

Totally agree. Unfortunately it's really hard in the UK to find any parts like this that aren't cheap C...ese crap. Britain used to make all these kinds of things, but all those companies have long since closed down. I searched for ages and still couldn't find any quality fuses.

Well shit, I just got a whole bunch of cheap Amazon fuses. I've got a scope and PSU, I'm gonna set up the same test you did and see if they are junk. Thanks for posting!

Love your videos. Thx

Thanks for sharing. You helped me saving money.

This topic was covered a year or more ago, with comparison tests as well. ALL the colors of blade fuses from parts unknown would hold 40 AMPS ... be they molded as a 5, 10, 20, 30 OR 40. A USED CAR LIKELY HAS SOME OF THESE. The hazard is from putting in a no-blo fuse into a bad circuit that popped the GOOD ( blown ) fuse, without diagnosing and repairing the vehicle. Expect to ruin a wire harness or worse.

Great info. Thanks!

😮!!! Im sure I have a box or two of chinesium fuses that I need to check.

Thank you so much for this information.

If I remember correctly there was a huge bruhaha several years ago about these Chineseium fuses not working properly and were extremely dangerous.

Very good illustration. I look forward to seeing the crowbar device. I’ve always been mystified that little premade in-line crowbar devices aren’t on the market. I’d love to see some adjustable ones that could be used on 13.8 or even 5v applications. I tend to tinker with power supplies and have modified some to have remote sensing, but I’m always worried that something will go wrong and the devices being powered could see high voltages if the sensing wire ever became disconnected.

Super thanks man . I had no idea

Amazingly worrying - thanks for alerting everyone.

I remember a 528e back when German cars use ceramic/thermosetting strip fuses . Red 16 white 8blue25. It was burned out in the roof from a dome light short. The fuse was replaced from white to blue.