We used a welder once to dry out a 250' long buss duct that was soaked when an old metal roof started leaking right into it at first it just blew the 3k amp fuses at night when the plant was shut down, so when we can in on Monday we had no power for the MDPs fed from it, and when we investigated as to why the fuses failed well it was self evident when we walked the duct down and found water all over the place about at the 235' mark of the run, the amount of ruse that ran into the buss is what got the fuses so we had to open that section and clean it out and we had 4 or 5 insulator knobs we had to replace, so our plant EE came up with this idea if a welder can be used to thaw out frozen water pipes in a house or underground, it should work for this, we removed the cables feeding it from the service and bonded A to B together at the east end with a jumper from C to the building steel and took one of our Hobart motor generator welders with a very high amperage capacity (1200 amps) over to the other end and lugged B to C, and bonded the work lead to the building steel and the stinger lead to A to put all three phase in one big series run, with the amperage all the way down we slowly brought it up till the IR thermometer read 150° we kept an eye on it and let it bake for about 4 hours, after that we megged it out, put a large drip pan over the buss at the leak point which had stopped because the storm moved on, and put it back in service, lasted about two years before it just let go and started a ball of arcing that literally burned all the way up to the point of the multiple parallel 1k MCM conductors that just fell apart, funny thing was only one of the three fuses opened in all the arcing, and there was no buss-way anymore all splashed on the floor as melted globs of copper and tin from the casing, all we could do was used welding glasses while manning CO2 extinguishers to put out the little fires that was breaking out from a few stock piles of cardboard stock for shipping box's
Originally Posted by brian john
Last edited by hurk27; 04-30-12 at 11:27 PM.
Wayne A. From: N.W.Indiana
Be Fair, Be Safe
Just don't be fairly safe