I have a project involving loads of current circulating in a tuned circuit at 2-3 khz, and yesterday I suceeded in fusing a length of 35 sq mm copper multistrand welding cable - Any ideas what sort of current would do that? Googling I did find one reference to current density to fuse, and had the 35 sq mm been a solid bar it would fuse at 5,800 amps.
This was part of the feeder circuit to an induction furnace coil. Originally piped in 12mm copper pipe with a cross sectional area of 51 sq mm I had replaced it with 15mm pipe with a cross section of only
31.5 sq mm, so had paralled up a piece of 35 mm welding cable to give a total of 31.5+35 = 66.5 sq mm and thought it'd be easily enough. But as the pipes are water cooled and the wire wasn't the result was a fused wire ! (I'm now re-doing it in 3/4" pipe with a 68mm cross section so >>should