In your typical household panel there is no isolation. If you’re lucky there’s a GFCI for the bathroom and kitchen.
Edit: not to imply GFCI provides isolation either
Which is insane to me. RCDs have been required on all household circuits for decades in Australia. Literally saved my life when I was doing dumb shit as a kid.
Edit: Also, by typical, you mean a typical American household :P
I was thinking British, but my understanding of the technology you mentioned I don’t see any clear reasons why it would prevent back feeding?
It didn’t. The mains was on, and the plug was in my hand. My dad, in a typical show of his wonderful parenting, told 9-year old me to plug it in while he went outside to the fusebox to turn the main circuit off. The power came back on while I was walking out to the back shed. I still got a pretty big zap, in the eyes of a kid anyway.
In Murica, the kettle tripping a circuit breaker would knock out the fridge if the fridge was on that breaker circuit. Anything not on that circuit breaker is fine.
No isolation here just means that if the breaker doesn’t trip, the kettle’s circuit and fridge’s circuit are connected together in the circuit breaker box by copper bars.
