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.
maintenanceguy...i have a question.is this a 3phase panel.the reason i am asking is that maybe it's a motor that shorted and someone installed 3 single pole circuit breakers instead of a 3 pole cb.you can check exhaust fans ,pumps,etc..not the first time i seen this happen.if this is a new building check the oringinal prints on the panal circuit layout.you may get lucky.
what equipment is not working?????
the greenlee circuit tracer is a real good idea. ampprobe puts out one too.
#20336 - 01/13/0310:16 PMRe: Finding the other end of EMT
It is a 3Ø panel but these are 120V 1Ø loads, two are for recepticals and one circuit feeds three single phase exhaust fans on the roof. And these aren't adjacent breakers.
The building's aobut 20 years old and the prints show circuit numbers but not conduit runs. And there aren't any as-builts anyway so they aren't real accurate.
We do a little telco work and I've got a couple of toners/amp probes but can't use them here because the wires are shorted to the conduit. So everything in the buildng has tone when I hook it up. Is the greenlee circuit tracer likely to work where these won't?
#20337 - 01/13/0310:57 PMRe: Finding the other end of EMT
I have a crazy idea, (as long as there isn't a lot of smoke detectors that is.) how about blowing an orange smoke through the pipes. You should be able to detect that pipe somewhere. (You also might scare a few people if they don't know about the test.)
#20338 - 01/13/0311:31 PMRe: Finding the other end of EMT
What probably happened is your foundation settled and pinched off your conduit. It wont be any good to you, even if you did find it. In the time you have spent pursuing an un-tamed ornathon, you could have run a new conduit. Put down the tick tracer, go get your bender and get to work!
#20340 - 01/14/0305:22 PMRe: Finding the other end of EMT