After a minute, I think. Depends on your breaker rating.
20 amps on a 15 amp breaker will take a while to trip. You will have wiring damage.
20 amps on a 15 amp breaker will take a while to trip. You will have wiring damage.
The main issue is actually with the slightly-less trigger-happy breakers (class D) needing a sufficiently low resistance on the output to ensure that the magnetic trigger is both reliably triggered if you short the outlet, yet reliably not triggered by the current spike allowed from it's class. They trigger between 10 and 20 times the nominal rating, and 16 A is the typical circuit choice here. Ensuring that you reliably hit 320 A through a long circuit isn't the easiest/cheapest thing.
C/D are more appropriate for industrial use, where wiring and devices are designed beforehand, and people (ideally) won't just join together extension cords, and put multiple electric motors on it.
But yeah, D is indeed rare, and not typically found in domestic installations.
[0] https://schneider-electric.app.box.com/s/cgxddrh26v9tpd48d2k...
People don't usually count consumption of their devices, so plugging in pretty much anything that the circuit breaker will take is a fairly common occurrence.
The fact that they do not leads (non-electrician) me to believe that outlet types differ to prevent unintentionally plugging devices into inappropriate circuits, not to prevent intentional abuse.
The present example is just a band-aid fix for cases where lower-current devices are connected in through some intermediate wiring (UPS, extension cord, RV power system, etc.) with a plug consistent with its own, higher ampacity, and in this application, seems no more prone to abuse than a garden-variety 15 A duplex receptacle on a 15 A circuit.