Prime shipping hasn't been worth it for years, and Amazon often has higher prices than at other retailers or direct from the manufacturer. Their business model is just extracting dollars from people who have been conditioned to default to Amazon as their first choice for shopping.
Quality issues apparently have become so bad for them that they no longer want the defective item to be returned. It is yours to dispose of in any way you see acceptable. They will refund your money or ship a new product but they don't want the failed item. This has been true for me with garden planters, electrical components like pliers, crimpers, and lugs, automobile parts, and solar installation components. Every item that has failed or been found to be unfit for the purpose yielded a refund and a note that it is not necessary to return the failed item.
I review many of the products that I buy and give honest reviews. I also answer customer questions about items I have bought even if the answer they need is in the product description. I think so many people have lost trust in Amazon that they need to know whether descriptions are accurate or hype. It is impossible to tell just from reading reviews and when Amazon shows multiple <3-star reviews for a product I read all of them so I can decide whether user error caused the bad review or whether the product is probably not worth buying.
Amazon is broken and I am trying to get my wife to quit buying so much shit from them. I buy most auto parts, hand tools, etc from their manufacturer sites. I can trust things to be fit for purpose and durable.
For the love of god, do not buy any line-voltage electrical equipment/devices from Amazon. I wouldn’t even buy 12v/24v/48v electrical parts from Amazon. It is not worth the risk of a house fire, no matter how much money you save. I don’t care if it claims to be ETL and UL listed, buy it elsewhere.
Amazon’s supply chain cannot be trusted when life safety is a factor.
Please buy electrical material/electrical devices from a retailer or supply house with a trusted supply chain, it isn’t worth killing your family to save a few bucks on an extension cord.
As you say, anything that plugs into AC mains >= 120V.
Anything that, were it to malfunction could cause a home fire or plumbing flood.
Anything that could lead to injury or death were it to fail (like car or boat parts, safety equipment).
Anything that your family or pets eat.
Anything mission critical that you depend on to run your business/income.
(any other ideas?)
Anything medical. There was some talk of Amazon getting into (legal) drug supply, which could go very poorly.
After that I stopped buying safety critical things from Amazon.
Why would you buy anything from Amazon after that experience? I personally stopped buying things on Amazon when they gave up on having a trustworthy supply chain.
If you're reading this Louis, thanks for all your work and for fighting the good fight.
I'm always amused at how petty trillion dollar companies can be. Amazon killed his 7yr old affiliate account days after his first video critical of them. [0]
For reference twice rated current is usually supposed to make the automotive fuses blow in some seconds or less.
The worst thing is that Amazon is threatening to pull Home Depot et al. down with them in the race to the bottom, unless they are shut down hard. Quality control costs money and Amazon got zero.
I understand that people are under cost and time pressure.
But if you buy a fuse set on Amazon to save $10 off what a fuse assortment kit costs on Digikey, you are getting exactly what you paid for.
The signs are obvious: a nonsensical name like HOODOOVOOKOO, sold by BLXXYUSA a seller specializing in children's socks and fuses, quantity listed in "pieces", an obviously cheap plastic box, a ludicrous quantity at a per-unit price that is absurd.
Amazon is giving you what you want: the absolute cheapest possible item in the fastest possible time.
You cannot be angry at them for giving you exactly what you want.
If you cannot be bothered to spend more than 4¢ per fuse or spend more than 15 minutes researching the product, is the device you're protecting even worth replacing the fuse on?
What they want and were sold is a working fuse... which this is not. If I starting calling myself a medical doctor and advertising cheap surgery I would hope someone would try to stop me.
You can't claim to be empathetic and expect everyone to be a domain expert in absolutely everything to avoid getting poisoned, burned or killed by sellers lying to people.
Paper clips sold on Amazon cost 1.3¢ each. https://a.co/d/28pCOQ2
Edit: and I am unassailably certain that those paper clips are really bad paper clips.
It's so painful at this point I've just started building in a 30% markup in the price mentally to account for things I'm going to have to buy an extra copy of. Returning things isn't worth the hassle it except for with very expensive boxed sets.
As a "bonus" amazon has also removed my reviews on things that I've had a particularly high error rate with, since the poor quality is apparently not relevant to the thing they are selling.
- A 2A fuse needs to conduct 2A, no matter ambient temperature, manufacturing variation, age, etc.
- 95+% of the time, what you're protecting from isn't a minor overload condition but a short.
This means a reliable fuse purchased from the best manufacturer in the world won't blow at 2A. Something like 3-4A is perfectly reasonable. 5x rated current is not okay, but 2x is well within norm.
Even at 5x, though, the risk here is not huge:
- You've caught shorts which is the most common failure mode.
- Everything carrying current typically has a ton of safety margin built in, so even 2x isn't really a big deal.
- There's a fairly narrow set of failure modes which (1) won't blow the fuse AND (2) will still be small enough to be less than 5x.
- Those failure modes still need to occur near something flammable.
The key reason why there is a risk at all is that power is a square law of current. If this was 5x heat / power, I wouldn't be worried /at all/. 5x current is 25x power and 25x the heat, which is more of a problem.
https://www.nilight.com/products/nilight-272pcs-standard-min...
These are not slow burning fuses or whatever. In their product video 6A blows a 5A fuse in like subseconds. However 6/5 rated current should probably blow slower, like days, or not at all? The 2A fuse is probably just made faulty.
Edit: Of course, the Amazon seller could be a counterfeit of "Nilight", which might be a proper brand?
Those brands can be found on sites engineers shop on, like Digikey, Mouser, Newark, and similar (which also lets you price / order by the thousands, and feed into manufacturing channels, rather than by boxes of random parts). They will have datasheets, rather than Youtube videos. Better datasheets will often show:
* Typical and worst-case behavior
* I²t, which is used to compute how long it will conduct a given current
* Impact on ambient temperature on rated current
... and similar
Here's a few random fuse data sheets from Mouser:
https://www.mouser.com/datasheet/2/54/SF_1206HH_R-3304051.pd...
https://www.vishay.com/docs/28747/mfuserie.pdf
https://www.eaton.com/content/dam/eaton/products/electronic-...
Some of these are more complete, and some less. That's a fact of life. I can buy a fancy fuse which specs and tests everything for a bit more $$$ for a medical or military application, or one which doesn't for $ for e.g. a toy. If all I'm worried about is a short, that's good enough.
A Youtube video which shows a 5A fuse blowing at 6A means either:
1. The video was baked for Youtube.
2. The fuse will blow at 4A on a hot summer day, running in an even hotter enclosure, and you've bought a bad fuse.
My bet is on #1.
Those are the only three manufacturers I ever see specified by electrical engineers in construction specs.
Fuses aren't typically used to protect copper runs; breakers are. Fuses are used inside of electronics. Breakers are rated as you describe, to protect copper runs.
For fuses, this is a data sheet of a random fuse (first one on Digikey search; I didn't pick anything special):
If your 15A breaker tripped instantly when the current exceeded 15A, you’d be resetting a breaker every time you turned on a stand mixer or something.
Instead they have two mechanisms of action—thermal and electromagnetic.
The thermal trip time varies depending on how much you’ve exceeded the rated current, but for a typical household breaker could be a couple of minutes.
The electromagnetic trip is the “hard cutoff” where as soon as you exceed that limit the breaker trips near instantly. Depending on the type of breaker this is usually 5-10x its rated current. So your 15A breaker may allow you to briefly pull 75-150A through it.
So while these fuses are mislabeled and should not be sold, it’s not as much of a death trap as it might appear on first glance from what it sounds like.
The thing that worries me is what happens when everyone is cutting corners because they're relying on someone else building in safety margin. Where's the tipping point when everything becomes unsafe?
People get by. There isn't a sudden collapse or implosion.
It's also easy-to-manage. If there are suddenly a lot of electrical fires, regulators will step in before it goes out-of-control.
For my personal tastes, the US is too liability and safety-conscious on a day-to-day level, and not nearly safety-conscious enough on a system level. Risks like fires, where I live, are small enough that I'm not worried about them.
Antibiotic-resistant super-diseases? AI apocalypse? Thermonuclear war? Cyber-Armageddon (where every network-connected device is maximally bricked in the span of 30 seconds)? Climate change? Some weird super-pollutant? Systemic economic collapse? Civil war? Genetically-engineered super-bug? Running out of water in Arizona (or your other local issue)? ...
We have major disasters typically around once a century in any given location (WWI/WWII/30 years war/Bubonic Plaque/hurricane/etc.). It's hard to predict which one will happen; some are very unlikely, and some are pretty likely. If something hasn't happened in 50+ years, we stop worrying about it, and we completely ignore future previously-impossible risks.
I'm much more worried by those sorts of things than by fire safety.
Unless of course you _also_ bought it from Amazon, in which case, who knows?
Some are slow burn fuses and don’t pop until you exceed the rated amperage for a long time and by a lot of amperage. Not really what I expected. Some of the fuses do work like you’d expect and pop when they exceed the amperage by a minor amount.
One problem is that fuses are thermal devices. They break due to overheating. They take a while to warm up and blow. If a fuse overheats at 2A at 100ms, it will get that same amount of energy at at 20A over 1ms, which is an eternity by the standards of transistors.
Most silicon devices can destroy themselves in milliseconds or microseconds.
But these fuses aren’t labeled “fuses that will blow when there’s a sorry but not when there’s an overload condition”, they’re labeled simply as “fuses”, which should blow over their rated limit, full stop.
It violates separation of concerns if I have to think not only about the fuse itself but also the rest of the system that it’s plugged into.
It very much doesn't happen much when one is designing analog electronics, which is where fuses come up. If I'm designing a piece of medical equipment, it cannot kill a patient with any single point of failure. That's a systemic design issue, and any device, including a fuse, has to be seen in the context of the system it's plugging into.
It'd be possible to separate concerns, but it would result in grossly inefficient, over-engineered systems.
You do get a bit more of that in electrical (rather than electronics) work, since you need to count on idiot contractors who will screw everything up.
That's one failure mode. Damaged returns resold as "new" is another.
* A 25A fuse will conduct 52A-110A for 5-10 seconds, which is about the 2x in my original post.
* For shorter time periods, this goes up a lot (150-260A for 100 milliseconds).
I'm getting down-voted, but no one is posting contradictory information. This discussion feels more like reddit than HN.
As a footnote, at least in the US, in the 21st century, I've never seen a house with fuses rather than breakers. As you point out, copper is expensive, and a breaker is $10-$15. It's not only more convenient, but saves more money elsewhere.