Circuit breakers are not guaranteed to trip quickly for currents just slightly above their rating. Take the look at the trip curve for a QOB120, an unremarkabl

Circuit breakers are not guaranteed to trip quickly for currents just slightly above their rating. Take the look at the trip curve for a QOB120, an unremarkable residential circuit breaker: https://download.schneider-electric.com/files?p_enDocType=Tripping+curves&p_File_Name=730-3.pdf&p_Doc_Ref=730-3 https://download.schneider-electric.com/files?p_enDocType=Tr... The top end of the graph is labeled 10,000 seconds. If there's a marginal wirenut connection between the breaker and the powered equipment, you may not want to give it 2.7 hours to heat up, possibly catching fire. After a century of experience, we now design electrical systems with multiple overlapping safety systems. That photo of the plug shows an earthing pin, after all. That pin does nothing, and is not required for the device to function. It is only there in the event a connection fails and a live wire touches the metal case of the equipment. This is rare, but if you tour the parts of the internet featuring accidental deaths, bad grounding is an entire category of video. Think of it as a code smell. It not an error, and won't prevent the equipment from working. But it's not good.