We have under ground conduit that has been been hit with a drill bit. Not enough to trip cb. What is the best way to find the affected conduit when you have multible conduits UG. Can not shut down to megg cables. Cable was hit and caused ittle interruption did not trip cb.
short underground _?
- Thread starter jimbo123
- Start date
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ptonsparky
Tom
- Occupation
- EC - retired
Just leave it alone. You will find it, just at the most inopportune time. Take your choice. Planned or unplanned shutdown.
You could luck out and be retired, or it never causes a noticable problem.
You could luck out and be retired, or it never causes a noticable problem.
xformer
Senior Member
- Location
- Dallas, Tx
- Occupation
- Master Electrician
I would call the AHJ and notify him of the damaged wire. Then locate necessary companies involved in correcting the problem.
Cow
Senior Member
- Location
- Eastern Oregon
- Occupation
- Electrician
Is this a trick question?
How do you find an underground conduit? Usually by digging and/or sawing concrete!?!?
How do you find an underground conduit? Usually by digging and/or sawing concrete!?!?
ohmhead
Senior Member
- Location
- ORLANDO FLA
Well PD testing with power on no shut down needed .
You will find it!
You will find it!
ptonsparky
Tom
- Occupation
- EC - retired
What is PD Testing?
The Sun up there already?
The Sun up there already?
ohmhead
Senior Member
- Location
- ORLANDO FLA
Partial discharge testing its a safer way to test with power on you dont shut down lots of folks do it .
They send a signal at a freq down that cable not at 60 hertz but at higher level and check capacitance of cable your high voltage cable is a capacitor this is done while hot no shut down
This morning they had the corporate engneering at the site to go over what would have to be done to locate damaged wiring. Engineering has taken over for fear of losing production with loss of power. Sooner or later i believe they will shut it down to make repairs . Right now some of us have a long weekend to do.
Thank you for your responses on this issue.
Thank you for your responses on this issue.
ptonsparky
Tom
- Occupation
- EC - retired
What is the voltage you are working with on these lines?
kwired
Electron manager
- Location
- NE Nebraska
Are you trying to find physical location of the damage, or are you maybe trying to determine which set of paralleled conductors is the effected one, that could be a little more tricky to do without disconnection. Either way you will likely need to shut down to replace/repair.
jeremysterling
Senior Member
- Location
- Austin, TX
This maybe way out there, but here goes: Pump nitrogen into the drilled conduit and listen or feel for the escaping gas at the conduit stub-ups.
John120/240
Senior Member
- Location
- Olathe, Kansas
Maybe I'm having a brain fart, but I can not understand how that you know the
conduit was hit by a drill bit & not know where to dig ? Was it a directional boring
job ? How many sticks of drill pipe, measure then dig.
ohmhead
Senior Member
- Location
- ORLANDO FLA
Think safty
Think safty
Well word of caution if you put nitrogen into that conduit be safe your going to need some high pressure .
pressure & water its going to go in the direction of least resistance if its blocked that pressure will back flow to you what ive seen is the back flow of water coming into that hot gear . Use a little caution be safe and shut it down you have to anyway .
Ive blown conduits on lots of runs ive had the conduit back flow from the hose end many times and wet me down with lots of water under pressure it comes back and fast just be careful . And it might find a cut in the insulation and blow it with water in conduit!
Also nitrogen removes the air we breath so use a ventilator .
But i would not use Nitrogen or air in any conduit broken and hot not good .
If you had no other way put a amp probe on each feed find the one with out a load thats it !
Think safty
Well word of caution if you put nitrogen into that conduit be safe your going to need some high pressure .
pressure & water its going to go in the direction of least resistance if its blocked that pressure will back flow to you what ive seen is the back flow of water coming into that hot gear . Use a little caution be safe and shut it down you have to anyway .
Ive blown conduits on lots of runs ive had the conduit back flow from the hose end many times and wet me down with lots of water under pressure it comes back and fast just be careful . And it might find a cut in the insulation and blow it with water in conduit!
Also nitrogen removes the air we breath so use a ventilator .
But i would not use Nitrogen or air in any conduit broken and hot not good .
If you had no other way put a amp probe on each feed find the one with out a load thats it !
Last edited:
zog
Senior Member
- Location
- Charlotte, NC
PD won't work on LV cables. Not much you can do without a shut down. as others mentioned it is either a planned shut down to megger or unplanned later.
Sorry for misleading some and not explaining the situation clearly. What we were trying to find was the CB on the feeder, it did not trip for what ever reason which will determined when found. There was not a loss of power. It was a tricky job that could not be shut down at that time ,once they shut down it will be much easier to locate.
We are not apart of job anymore company called in their engineering depart saturday to handle things , which is a good thing.
Thanks for all the help.
We are not apart of job anymore company called in their engineering depart saturday to handle things , which is a good thing.
Thanks for all the help.
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