In a 100K sq ft facility, I've got three breakers that all tripped at once. The only thing common to these breakers is that the circuits they serve all leave the panel through the same conduit and these are the only circuits in this conduit. These serve an area of the building several hundred feet from the panel.
I've been able to isolate the three circuits by disconnecting devices to know that all the wires are probably shorted to ground and each other within this conduit run. I need to pull new wires but I can't find the other end. The conduit disapears into the concrete slap and the circuits show up inside a wall in another area as romex. I spent probably 4 hours today in drop ceilings, and attic spaces trying to follow this circuit and It's just not accessable enough to be sure I'm following the same wires.
I need to find where the conduit leaving the panel ends up. With probably a hundred pieces of emt leaving this distribution room, this is a challenge. Any tips?
Tone generator won't work with the wires shorted to ground. The best idea I've come up with is to blow air through the pipe with an air compressor and walk around listening for the hiss. Pretty poor idea.
Any suggestions appreciated.
