I wish there were legal protections around this. Using a standard plug means it should accept the standard for that plug.
USB-PD is in a twilight zone where it can deliver enough power to cause safety risks but, due to its low voltage, is not subject to the level of regulatory scrutiny that other electrical products receive.
To date, the USB-IF's approach to safety and interoperability does not adequately protect consumers. USB-PD devices should not be incompatible to the point of damage but USB-IF has been unable to ensure this by keeping non-compliant products off the market.
USB-PD needs to be pulled under the IEC, NRTL (US) and CE (EU) regulatory systems and compliance overseen by entities with the legal authority to deter legitimate manufacturers/importers from selling non-compliant products.
"You can plug it in, but it might catch fire" just isn't good enough for a power delivery system that can provide 100W.
It might help resolve certain really common cases like compatibility between the chargers and devices of the mainstream entities. I guess I'd argue that that should be happening on its own, but Nintendo definitely dropped the ball with releasing a USB-C product in 2017 that was interoperable with Apple and other name-brand chargers which had been in existence for two years previously at that point.
In this particular case I think even well-known name brand chargers which follow standards (Apple, Anker) are breaking the Nintendo, and that's unacceptable.
Nintendo should have taken more steps with their charger to restrict the Switch to authorized chargers only, rather than permitting unsupported chargers (such as standard USB-C ones) from being able to power it. Or even just outright used a proprietary connector!
None of this is any fault of the chargers. They’re the ones adhering to the standards correctly. The Switch is at fault.
If you shove 9V into a 5V device, bad things will happen, regardless of Nintendo is anti-standard or not
Their website says that it uses USB-C for charging and the charging port accepts stock USB-C cables, it's not even remotely reasonable to bury within the warranty a statement which says "oh, by the way the device cannot accept USB-C cables -- if you use a made-to-spec cable that fits in the port, no warranty for you!".
They put USB-C on the box. They screwed up the design. They should be forced to have a recall, or extend the warranty.
Imagine you go to a hotel and see an USB A port on the wall and you try to charge your phone, then your phone starts to smoke or simply ignites. You find later that port was not a standard USB A port, but a 220 volt plug for something custom. Should the hotel be responsible for that? I think it should. If it looks like a duck ...
It would have been better if they'd launched another dozen different plug standards. In situations when there's only one thing you should be connecting to your device, that's the way to go. Universal sockets only make sense if they're actually universal.
Nothing above seems related to the standard. At the end of the day, its still comes down to the manufacturers to follow the standard in order for everything to to work. But the standard itself can't stop any particular manufacturer from making a non-compliant product.
Edit: A poster below this question said they fried their Switch by using their Macbook charger so I may have been naively optimistic in my original statement.
Sadly, the legal burden is placed exclusively on the buyer (via electrical code).
Generally, where there's a 30A circuit, a 15A circuit is also available, but there are exceptions. You may have wired a RV hookup with only a 30A receptacle, but you want to run some lights, or tools or ? with a 15A plug from that on a temporary basis. The circuit is (presumably) good for 30A, so adapting to a lower amp receptacle is reasonable --- it won't hurt anything to draw fewer amps through the circuit.
Adapting from a 15A socket to a 30A socket can be dangerous; the 15A or 20A[1] breaker or fuse on the circuit won't immediately open with a 30A draw, and the wiring will heat up during the time it takes for the circuit protection to open; possibly long enough to cause a fire. Of course, just because a load has a 30A plug doesn't mean it draws 30A all the time, there are conditions where using such an adapter is safe, but it requires knowledge of the load.
[1] US NEC code allows for a 20A breaker on circuits served by 15A receptacle, as long as there is more than one receptacle
The outlet plugs specify the circuit breaker limit. Most consumer electronics in the US use a 15amp plug, which can be plugged into a 15amp outlet or a 20amp outlet — but no higher, due to physical incompatibilities in the outlet design.
The electronics that use the 15amp or 20amp plugs are therefore built not only to draw no more than the amps rated by their plugs, but also to self-destruct relatively safely if they draw the maximum amps available from the circuit breaker backing that plug.
So if a cheap device correctly assumes as part of its "don't explode" protections that it will never receive more than 20amps due to using a 15-or-20 amp plug, and then it short circuits while plugged into a 25 amp circuit using an adapter, it could very well explode, because the basic guarantees of electrical safety were violated. The plug used guaranteed it would never receive more than 20amp, and now it's receiving 25!
This is especially relevant when you're considering how to make use of an idle 30A dryer outlet in a garage. If you just plug an adapter into it, and your device short circuits, it will explode even more violently. Risk of harm increases with outlet power.
There exist fancy "breaker box" adapters that have a 30A plug on one side, a fuse box with a 15A or 20A fuse in the middle, and a 15A outlet on the other side for you to use. It's not really an adapter at that point, but the presence of that 15A/20A fuse provides the missing piece of protection for your 15A/20A device that a plain adapter wouldn't have.
So in summary, the only way to safely use a 15amp device on an outlet that delivers power higher than 15-20A is to somehow inline a 15-20A breaker between the device and the outlet (or, to rewire the outlet and its power feed to 15-20A).
TL;DR: Hire a licensed electrician to tell you what your options are and decide how much you care to spend and whether you want to make permanent modifications to get the job done.
No safety margin can account for purposeful circumvention, which is what connecting a 15/20A outlet to a 30A circuit is.
I didn't say any difference was unacceptable, but a significant difference for 20/25 should not be accepted.
If the danger gets gradually worse for every 5 amps on the fuse, that's fine. Then the excess danger at 25 or 30 amps is only a tiny fraction of the excess danger at 100 amps. Good work.
If the danger has a sudden sharp increase at a certain amperage, then that amperage threshold needs to be further away than a mere 20/25 difference. Or even 20/30.
Most lamp cords are only sized 100ish Watts or ~ 1A with the bulb being the only fuse. If these somehow pulled 15A for any amount of time the wire would quickly get smoking hot but you still plug them into a 15A plug.
Devices are supposed to protect themselves. Most 15A devices will cause fires if they actually pull 15A for any amount of time. If you try to use a a small extension cord on your space heater, you will soon be smelling burnt plastic while never getting over 15A draw. That is part of why these are such a fire hazard.
Alos in the US a 20A socket is designed to allow a 15A plug to work in it, But not the opposite way as that would cause issues in the wall.
The actual range was a bit different by Ampage which I never quite understood.
The reverse of this is plugging big loads like power tools or vacuum cleaners into extension cords intended for use with desk lamps, but I think most people understand that that's a bad idea.