A salutary lesson from a few years ago.
We were getting lots of power cuts in the village, so I bought the afore mentioned generator in the middle aisle of a famous German supermarket.
I then contacted our electrician who installed a mains switching circuit to it.
It was the summer, so I left it out and sure enough a few weeks later, we had a power cut. I smugly went out, fired it up, switched from mains to generator and went back in to continue watching a mindless TV program (I was still into TV back then).
A couple of days later, I met a neighbour and explained my success with great glee. After listening to me for a few minutes, I asked what he had done, to which he replied;
We joined everybody else in the village in the pub, where we ate and drunk the place dry and had a party.
I didn’t like my generator very much after that😂