It's a maximum rating, it's very unlikely that the equipment behind the cable is using anywhere near that. By the way 20A is the typical plug and cable in a hom

It's a maximum rating, it's very unlikely that the equipment behind the cable is using anywhere near that. By the way 20A is the typical plug and cable in a home, it's really not hinting at special equipment. If the equipment really used 20A continuously (100% sure it doesn't or it would be rated higher), it will take a long long time for the circuit breaker to heat up and trigger, like a whole hour. See charts https://en.wikipedia.org/wiki/Circuit_breaker#Standard_current_ratings https://en.wikipedia.org/wiki/Circuit_breaker#Standard_curre...