I have an old style fuse box with edison stule fuses. ive been having an A/C unit problem thats causing fuses to blow. the problem is the fuse block that the fuse screws into seems to be going bad when the fuse blows. ive replaced a block once already assuming it just went bad. after replacing it and trying to trouble shoot the ac unit issue a fuse blew again and the second fuse block went bad as well. when i say it went bad, it seems to be loosing its ground. checking the socket with a multi meter prior to the fuses blowing i would get 120v on each side and 240v when i went from pin to pin in the center of both sockets. after the fuses blow i only get 18v in each socket but still 240v feom pin to pin. i dont understand it because its just plastic and copper and the connection to the panel is good. if anyone could shine some light on this i would appreciate it.