The inverter box contains circuitry that cuts power output within some specified number of milliseconds if unplugged rendering the prongs "cold".

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danans 2 hours ago | parent | next [-]

It's not so much being unplugged as it is sensing whether the mains power is down. If it is, they stop backfeeding immediately, just like hardwired solar inverters do.

If this weren't done, there would be risk of electricution to anyone working on wiring in the house or on the utility distribution network.

	▲	Kevin_Flynn 2 hours ago \| parent \| next [-]
		They have to sync up and feed power in phase with the grid when its up as well, in the case of net metering setups.
	▲	ortusdux 2 hours ago \| parent \| prev \| next [-]
		It's also important for the male plug prongs to not be live when unplugged.
	▲	bronco21016 2 hours ago \| parent \| prev [-]
		I commented a little too quickly and left the nuance out. Your answer is much better!

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zanderwohl 2 hours ago | parent | prev [-]

Thanks. I would have asked Claude or something but I know so little about this topic that I wouldn't have been skeptical enough of its answer.