Page 1 of 2 12 LastLast
Results 1 to 10 of 11
  1. #1
    Silver Member
    Join Date
    Dec 2005
    Posts
    108
    Location
    Vermont
    Tractor
    MF 1428

    Default Finding a short in buried cable.

    My well is a shallow well 1000 feet from the house. The well guys tell me that there must be a splice in the underground cable that has corroded as they cannot get 220v to the well. The current cable is a high quality 4 wire underground cable that is deeply buried but not in conduit. They say it is unlikely that anything happened to the cable itself and that because of the distance that it is very likely the cable was spliced and that the splice is the problem. They say that they cannot find the splice and that the only solution is to bury a new cable. The well guys are honest but TBNers are a clever lot so I figure I would ask: Anybody know of a way to figure out where the splice/fault might be so I do not need to get the excavator to bury a new cable?

  2. #2
    Bronze Member wykubotaguy's Avatar
    Join Date
    Apr 2010
    Posts
    64
    Tractor
    Kubota L3400DT

    Default

    Get an electrician with a fault locator and he should be able to locate the fault within inches and give you the depth as well.
    2008 Kubota L3400DT w/LA463 FEL. KingKutter Tiller II 5ft, Leinbach L7200JR. 16ft H&H tilt bed trailer.

  3. #3
    Super Star Member k0ua's Avatar
    Join Date
    Jun 2009
    Posts
    17,722
    Location
    Branson, Mo.
    Tractor
    Kioti DK35se Hydrostat

    Default Re: Finding a short in buried cable.

    A Time Domain Reflectometer ( also just known as a TDR or cable radar) will find it in a heartbeat (local phone tech. or cable tv tech) might be able to talk one into helping you. If it is an open, you might not be able to do any good with a digital Ohmmeter. But I would try all combinations of the wires from both ends to see what I could learn anyway with that method. If its direct burial, or in PVC a cable tracer (signal on one end, and hunt with a pickup loop along the route) might be able to locate where the signal stops. But if you can get your hands on a TDR that is the way to go, will usually locate it within a foot or two. Good Luck

    James K0UA
    James KUA

    Kioti DK35se hydrostat with 2 QA buckets, 48 inch. King Kutter Rotary Cutter. 750 lbs ballast box. Loaded tires, Construction Attachments SSQA Lightweight Pallet forks. EA 50 inch single lid "wicked" Grapple. Satisfied Everlast PA160 welder owner How to add a link to a post . Best way to search TBN


  4. #4
    Super Member
    Join Date
    Feb 2006
    Posts
    9,124
    Location
    VA
    Tractor
    JD2010, Kubota3450,2550, Mahindra 7520 w FEL w Skid Steer QC w/Tilt Tatch, & BH, BX1500

    Default Re: Finding a short in buried cable.

    By 4 wire Im thinking you have 2hots, neutral, and ground. I wonder why you need the neutral for a 220 well. ... Anyway, do you have a short between 2 wires that should be insulated from one another - or open wires that should conduct end to end but wont? The difference is important. A short between 2 wires can be found with low tech pretty accurately by applying a precise small voltage to the 2 shorted wires and determining the current that flows. You would do this from one end and then the other. Unless the short is dead center the currents will differ and by that proportion will tell you which way from center and how far. If the problem is an open wire I think the open can be found by pinging the wire electronically and listening for an "echo" caused by the discontinuity at the open place. The timing of this echo would tell the position. You need a friend at an electronics lab - or maybe the power or phone co? One that deals with RF transmission should have the equipment for either scenario.
    larry
    This side of 40
    JD2010, Kubota L3450/FEL w SK QC, L2550 w FEL
    Mahindra 7520 [Pinky] /FEL w Skid Steer QC/w Tilt Tatch & BH, BX1500 [Mighty Mouse]
    IH37 Baler, CCM165 Drum Mower, JD Rake
    JD 127 bushog, Flail, SK Tilt Tatch , KK tiller, Rhino rear blade, Post driver, post auger, chipper, pallet fork, Grapple/Loader Buddy, Homemade Splitter/DC Welder

  5. #5
    Gold Member
    Join Date
    Jun 2007
    Posts
    425
    Location
    Northern West Virginia
    Tractor
    JD

    Default Re: Finding a short in buried cable.

    SPYDERLK,

    Good answer, because it is common for people to say "I have a short" when they mean "I have an electrical problem".

    I think it is probably an "open" (a break in the line). Otherwise the OP (original poster) would probably have mentioned tripped circuit breakers or blown fuses.

    Given that, I would support all of the responses about having someone use a TDR (Time Domain Reflectometer device that can locate a break) find the break. I just saw the sale of a used TDR on eBay for $150. Surely you can have someone check for a break for less than the cost of replacing the 1000' line.

    I agree that the problem is most likely at either end, or at a splice in the middle.

    Personally, I set a post where there was a splice in my line, and buried a lot of aluminum cans not too deep directly above the break to make it easy to locate with a metal detector in case the post disappeared over the years.

  6. #6
    Super Member Mace Canute's Avatar
    Join Date
    Nov 2006
    Posts
    5,399
    Location
    Saskatoon, Saskatchewan

    Default Re: Finding a short in buried cable.

    Quote Originally Posted by wykubotaguy View Post
    Get an electrician with a fault locator and he should be able to locate the fault within inches and give you the depth as well.
    X 2. Fault locating isn't hard to do, you just need the equipment. I used to do quite a bit with a unit like this before I retired.


    It could be a bad splice, but it could also be a case of insulation failure, either a pinhole from when it was manufactured or possibly damage from handling or it could be damaged by something it was buried with, like a sharp rock. A fault to earth won't necessarily trip a breaker, the earth resistance can be high enough that the breaker sees it as just a load...I've seen that happen. Several years ago a guy called in that there was steam rising from the ground out in his back yard so we went out and checked. Sure enough there was a hole in the snow and a small pool of water in the lawn, maybe 6 - 8 inches in diameter and it was bubbling merrily away...electrolysis, eh? It did warm it up enough to raise the temp high enough to thaw the earth and melt snow but it definitely wasn't boiling...I checked after the power to it was shut off. Turns out the previous home owner used to have a pool house out back but had torn it down and filled in the pool before he sold the house but they didn't remove the electrical service to it, just buried the bare ends underground. They probably just opened the breaker and left it like that but the new owner turned it back on not knowing what it fed but thinking it had to be on.

  7. #7
    Bronze Member Botetourt's Avatar
    Join Date
    Jun 2011
    Posts
    53
    Location
    Virginia
    Tractor
    Mitsubishi 470D

    Default Re: Finding a short in buried cable.

    this may not work in your situation, but I was amazed at how it worked for me. I found a break in my Invisible Fence wire quickly with a cheap pocket radio and an "rf choke" from Radio Shack. I put the rf choke on the transmitter and waved the radio over the rough location of the wire till I found the break. It was cheap and fast, maybe some variation of this will help you.

    How to find a break in an invisible dog fence

  8. #8
    Gold Member
    Join Date
    Apr 2005
    Posts
    392
    Location
    SW Minnesota

    Default Re: Finding a short in buried cable.

    Problem with using a TDR is that most of the newer units are set-up for a select VOP Velocity of Propegation. I have an old Tektronics 1502 that would get you within twenty feet each side. Proglem is I would have to coem operate it for you.

    Don;t know where you are located, but if you have a smaller electric coop near you call and talk to them and ask them if there is a contractor around that can thump faults for you. Basicly they charge up a large capacitor and throw the switch the fault shows up real well and they then can TDR the wire or look for a hole in the ground.

    USing a small AM radio will find it also Get the line located energise then tune to the low end of the spectrum and walk along the line. When you hear the buzz get louder you are near. At the loudest point should be your leak RF travels straight up thru the earth.
    DX35, MF65. Attachments= all of them.

  9. #9
    Veteran Member
    Join Date
    Nov 2004
    Posts
    1,084
    Location
    Oregon
    Tractor
    JD 770, Yanmar 180D, JD 420 (not running), had a Kubota B6200

    Default Re: Finding a short in buried cable.

    I had a similar problem last December with direct bury wire. Well just stopped working. Fault locator guy said "dig here, it's 36" deep" and when we found the wire there was no visible damage. Could have been pinhole, as Mace suggested. He used a gadget similar to what Mace showed in his pic to locate the "fault". I wasn't convinced the fault was there, but maybe it was.

    Well guy gave us temporary power, but said our tank was also bad.

    I paid an 18 yr. old kid to dig a new ditch (I'm 67 yrs. old and it rained every day with temps around 36F and a wind blowing--it was worth it to pay the kid), then I laid the conduit and had one of my buddies from the Air Guard who is an electrician and works cheap but not free, run new wire. Then the kid filled in the ditch.

    Wire (a big expense, copper isn't cheap these days), conduit (cheap), labor (the kid, the well guy and the electrician), new tank, etc. for 110 ft. ran $1,800.

    For the distance you have to go it looks to me like a repair job is in order rather than replace like I did. There were lots of good posts on TBN on how to splice the line.

  10. #10
    Super Member Mace Canute's Avatar
    Join Date
    Nov 2006
    Posts
    5,399
    Location
    Saskatoon, Saskatchewan

    Default Re: Finding a short in buried cable.

    Quote Originally Posted by Pilot View Post
    I had a similar problem last December with direct bury wire. Well just stopped working. Fault locator guy said "dig here, it's 36" deep" and when we found the wire there was no visible damage. Could have been pinhole, as Mace suggested. He used a gadget similar to what Mace showed in his pic to locate the "fault". I wasn't convinced the fault was there, but maybe it was.

    Well guy gave us temporary power, but said our tank was also bad.

    I paid an 18 yr. old kid to dig a new ditch (I'm 67 yrs. old and it rained every day with temps around 36F and a wind blowing--it was worth it to pay the kid), then I laid the conduit and had one of my buddies from the Air Guard who is an electrician and works cheap but not free, run new wire. Then the kid filled in the ditch.

    Wire (a big expense, copper isn't cheap these days), conduit (cheap), labor (the kid, the well guy and the electrician), new tank, etc. for 110 ft. ran $1,800.

    For the distance you have to go it looks to me like a repair job is in order rather than replace like I did. There were lots of good posts on TBN on how to splice the line.
    A pinhole in the insulation can be the start of the problem but by the time things quit working, the conductor will have corroded off and the fault is usually quite obvious, moreso with aluminum conductor than copper. When copper conductor is almost all corroded away, the little bit left heats up from the current flow from the load and sometimes from flow to earth and usually causes the insulation to melt enough to be obvious. Aluminum turns to aluminum oxide which swells considerably and makes the fault quite conspicuous.
    Fault locating is more an art than a science sometimes. Darn machines lie to you!

Page 1 of 2 12 LastLast

Similar Threads

  1. Winch cable question
    By easygo in forum Build-It Yourself
    Replies: 7
    Last Post: 04-21-2010, 11:56 AM
  2. Inovative anti-theft ideas?
    By woodlandfarms in forum Owning/Operating
    Replies: 142
    Last Post: 04-24-2007, 11:48 AM
  3. Independent PTO engagement cable Breaks
    By GreatWords in forum Parts/Repairs
    Replies: 0
    Last Post: 01-22-2007, 09:48 PM
  4. Electrical ground cable problems on L3010?
    By woodchuckc in forum Kubota Owning/Operating
    Replies: 5
    Last Post: 10-10-2003, 03:13 PM
  5. What all should I put in a trench?
    By Kyle_in_Tex in forum Rural Living
    Replies: 17
    Last Post: 03-09-2003, 09:46 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2014 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.