I'm not surprised by the results that Louis Rossmann found in his experiment. And I have absolutely no intention of attempting to discredit such findings. nor the knowledge of Louis Rossmann.
Private tests were done on Bussmann ATC (made in the U.S.A)and bulk Dynaline fuses (imported from China) specifically sold in this region.
Test rig was a 0-40V 0-20A DC power supply, electronic load, and Bussmann ATC fuse panel. 2 DMMs and a precision DC current clamp to confirm readings. 5 test samples from each manufacturer confirm the findings of Louis Rossmann.
But there is some thing that gets neglected and misunderstood in many tests done to various products privately imported from other countries.
Products produced here(North America), must comply to the regulations specified by the particular legislative bodies that oversee the manufacturing, testing and sale of such products.
All fuses
manufactured in North America are subject to tests and standards set by UL, IEC, NEC, CSA, and other regulator bodies that may be applicable to the product. Automotive Fuses manufactured in North America are no different but are also subject to scrutiny from the Automotive Standards Council.
So these Automotive fuses manufactured here would have a fusing current of 125% of rated. As an example, a 5A standard blade fuse under the UL standard should break at around 6.25A.
Tests that I did on 5A standard ATC blade fuses confirm that standard.Eaton Bussmann fuses used in the test are subject to UL standards and the Automotive Standards Council and are listed as such.
Also keep in mind that even imported fuses used at the time of automotive manufacturing must also comply to these standards and imported vehicles must have Fuses that comply to the standards set by North American safety standards, Department of Transportation and other such regulatory institutions.
But these standards do not apply to fuses sold as general purpose. The fuses that are sold at various outlets such as Amazon, Ebay, Aliexpress, and other sources are in fact compliant to IEC standards and do not need comply to UL or ASC standards. Manufactures outside of North America, European Union, UK and Oceania (Australia New Zealand) only need to comply to the IEC standards.
Finding the IEC standards can be difficult, since the literature must be purchased from the IEC. What information that is available freely can be vague and scattered. This inability can often lead to radical conclusions about many products.
The IEC does not cover specific automotive standards other than the coupling of EV's to grid power. The standards used for low voltage, low amperage is covered under the IEC 60269-1 to 4 and IEC 60947-4-1, apply to fuses used and/or sold
Outside regions regulated by the UL and Automotive Standards Council, including similar regulations adopted/legislated in other regions around the world.
After some digging, these test standards can be viewed here
EEP under Conventional Non-Fusing and Fusing Currents. As the table states, the fusing current can be a much as 2.1 times the nominal current rating for fuses rate below 4Amps
I will neither condemn nor defend Amazon, Aliexpress and other such vendors for selling these fuses in North America since there are no applicable regulations that govern their use for general purpose. Even bulk fuses sold here may not follow UL compliance. UL compliant standard Blade fuses can be purchased at these vendors and may even be listed as such. But this compliance costs more. If you buy cheap, you get cheap.
The purchaser must be aware that the safety regulations here do not necessarily apply to other countries and that some products that are imported and sold here need not comply to the national safety standards if the product is for private use or general purpose.
People must do their own investigations concerning the safety of the products that they buy. Trust but VERIFY. Or purchase such products from reputable vendors and/or manufacturers that must comply to the regulations applicable to the product.
As a note. The fuses that I tested did indeed follow either UL or IEC compliance. The fuses that Louis Rossmann fell way outside any compliance and that people need to be aware that such products exist.