# Fault locating in underground wire(secondary)



## Ty Wrapp (Aug 24, 2011)

Here is how I locate telephone cables....

1. Locate path of cable

2. measure to fault with meter
http://www.all-spec.com/products/26500-000.html?utm_source=bingads&utm_medium=pla

3. Start digging!


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## Big John (May 23, 2010)

A time domain reflectometer probably would've caught that. Check out the Fluke TS90 or TS100.


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## Cow (Jan 16, 2008)

I bought one of these and it just showed up on Monday. I grabbed a roll of 12-3 MC and 14-2 NM last night to do some testing on. I hope it works great, it's my most expensive meter yet!


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## Big John (May 23, 2010)

I've never played with a megger version. Looks fancy as a mofo. What all does it do?


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## macmikeman (Jan 23, 2007)

http://www.megger.com/us/Products/ProductDetails.php?ID=1715&Description=cfl


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## macmikeman (Jan 23, 2007)

Check the data sheet pdf. It looks pretty awesome.  Cost is comparable to what I spent for my first digital megger.


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## xpertpc (Oct 11, 2012)

put some DC through it and use a compass -


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## Spunk#7 (Nov 30, 2012)

Thanks for all the replies. How close will these (TDRs) get to the fault? I don't have any experience with one. I always thought TDRs gave you a number and you measured from that? Is that correct? Most of my locating is in wet,swampy,wooded,underground areas.


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## raldous (Aug 6, 2009)

A good TDR with an experienced operator can get within inches of a fault. 
Used in conjunction with a locator (if you don't know the actual path of the cable) you should be able to point right at the bad spot. 
When I was in charge of the communications system a local road-course racetrack, i had some old six and twelve pair telephone cables, some of which ran through a swampy area. With a TDR I was able to see where the cable entered the swap and where it exited, along with locating a fault in else where in the approximate 1500' run.
If you deal with underground cable with any frequency, it will pay for itself.


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## nrp3 (Jan 24, 2009)

I have played with a couple different TDRs and haven't had much luck using them on UF. May be technique or the particular models, not sure. Been using Aquatronics EG3000 for locating UF faults with good success. Tough if theres no contact to ground.


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## Spunk#7 (Nov 30, 2012)

The thing I was inquiring about is a device that will shoot a DC pulse or surge through the outside jacket of UF or a splice wrapped with rubber tape, providing a path to ground(dirt). I was wondering about the possibilities? Higher voltage meggers,some kind of hand cranked generator,etc.


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## nrp3 (Jan 24, 2009)

I can dial up to 3000v on mine and it will usually find its way through a dead splice. The damper the earth the better. It's not always perfect, but more often than not, I find it.

What model and brand of fault locator are you using?


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## 480sparky (Sep 20, 2007)

If it is faulting to earth, then a basic fault locator (with an experienced user) will nail it.


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## Spunk#7 (Nov 30, 2012)

I use a Timco Spitfire since 2003,works great. If the fault doesn't have a path to ground I don't know any that work. The UF has two layers of insulation,old splices were split bolt with a lot of rubber tape around them and no path to ground even though they are faulted.The technique I described is used for high voltage cables,burning through insulation at the fault location to provide a path to ground. My original post was wondering if anybody had ever tried that technique,with much lower voltage on secondary problems. The Timco Spitfire work on both powered and dead fault locating,to 600 VAC.


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## nrp3 (Jan 24, 2009)

Sometimes a different day might make a difference. Like I said, wetter the better. Patience helps, its not always slam bam here's the fault. Could also be right under the light itself. I've seen people add a segment of lights and just cut in using nothing more than wirenuts and tape. The Timco is a nice unit. Used that too.


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