Locating a Short in direct burial line

[bbartmasse r]

I went on a service call today. Breaker tripping. Panel from a barn feeds a small(surely non-permitted) old building with 100 amps. 2 hots and a neutral, no ground. Direct burial wire.

I pulled the wire off everything on each side and was getting consistent continuity between neutral and one of the Hots.

My question is what is the next step? Can a short like that be located or do you just throw in the towel and figure you have to dig a new trench and lay down new wire?

Is it even worth further investigation? I am mainly a solar guy so do not have a ton of experience with this kind of thing.

thanks

 

[ActionDave]

We patch them all the time. Wire tracer and a fault finder, some crimp on connectors and heat shrinks, oh and a good shovel.

 

[jumper]

... oh and a good shovel.

An apprentice is nice if also available....but yep.

 

[ptonsparky]

We spend a good part of the summer patching faults. Megger, Cable finder, Fault Locator, and depending on the estimated depth a small excavator. None of us are under 40 now.

Remove wires from terminals, meg all the conductors. Locate & dig up the first bad spot(s). Cut back to good conductor, Meg again. Repeat process. Don't splice until you are sure there are no more faults. We suggest new, in a raceway, after two holes and there are still more problems.

 

[bbartmasse r]

Than you!

can someone expand on the process of actually locating the position of the fault.

 

[ptonsparky]

Than you!

can someone expand on the process of actually locating the position of the fault.

You buy the equipment. $1000 or so.

Mine injects a 500 volt pulse into the faulted wire. The receiver is mounted on an inverted U shaped handle with two probes you stick into the ground. Sponges soaked in saltwater solution and tied to the probes help when locating faults under concrete. A needle on the analog receiver swings to the direction of the fault. Passing the fault will cause the needle to swing back in the other direction. Basically saying "Go this way stupid, NO, to far!" Mine is 20+ years old and the newer ones may be even easier to use as well as more expensive.

There are limitations. The POCO in this area used to bury a bare cu grounding conductor in the PVC conduit with the conductors. I cannot do a locate on those. With that situation in mind, continuous metal piping in close proximity may give you problems.