Quote from Tim in Brother, Can You Spare a Hot Rod?
Al: Now, the cables are controlled by a thermostat. They turn on when the weather gets cold and they turn off as the temperature rises. Tim: We've already set the thermostat. Let's show the audience how it works. [sizzles] Al: How much voltage did you put in this? Tim: 240. Al: I believe it's only regulated to 120. Tim: Right, but it would take 24 hours to melt the ice so I juiced it up a little bit, 'cause we got a show to do here, Al. Look at that. No more blocked gutters. [After sparks fly and run along the coil, the portion of the roof below the zig-zagging cables is cut clean off]