Many moons ago, I worked at an old Strowger telephone exchange in the UK which had a BIG room full of single-cell lead-acid batteries, each about 3 x 3 x 4 feet wired to give 50V with big copper bus bars about 2 x 1 inches feeding through a hole in the wall. One day someone dropped a large wrench which landed across the bus bars and created a large flash and bang; we ran across the room to see what had happened and there were 2 ends of the wrench welded to the bus bars with the center part drooped on either side and blown out like a fuse. The exchange kept running although I expect there was a click on people's phone conversations.
I would not use my AN8008 for 400 volt work, the CAT info printed on the case is pure fiction IMHO.