Friend of my dads just called and asked me to come out and check out his hot water tank.

said it blew a fuse the 2wires coming out of the fused disconnect white wire was black and burnt looking and the black wire wasn't hooked up.

so the system had a black wire on the top and white going threw 30amp fuse and on the bottom only the white was hooked up and looked burnt up.

said it has been like this for 20yrs or so he put in a new tank 5yrs ago after the flood in our area.

i looked everything over and replaced the fuses hooked up the black wire and turned on checked out the voltage at all terminal and everything seems fine. and he now has hot water. the wiring in this house is very old and a mess i told him he should get someone in there to fix it.

why wouldn't someone hook up the black wire on this system, they way it was hooked up it had to be running on 120v not 220v?