Any tricks for finding a nicked wire?

Discussion in 'Irrigation' started by jcom, Oct 12, 2007.

  1. jcom

    jcom LawnSite Senior Member
    Posts: 791

    I will be using our 521 to find a nicked wire that is probably nicked along with the common.

    Any time saving procedures to track this problem?

    John and thanks.
     
  2. Having the fault finder (901 921? never can remember) helps a lot but if all you have is the 521 here is how I'd do it. Hook up just to the common at the timer with the 521 well grounded. MAKE SURE YOU HAVE FRESH BATTERIES IN IT. When you turn it on watch the needle on the main box not the wand. If it jumps to 8 by the time you get to 4 on the switch you will be far from the nick. If it stays below 8 on 5 you may be fairly close to the nick. I'd then trace the common at full strength and flag the path. Then I'd turn the wand down to half strength and go back over it close to the ground very slow. Nicks tend to bleed into the soil and sometimes you can follow a nick and never get a clue as to where it is. So when you start getting different or weaker sounds on the path you want to double flag those areas for potholing and checking. Use your Station Master but don't trust it completely since I've seen the SM go right through a nick and turn a valve on. I'd have the SM on before checking the wires to see if you are past the nick. If you are lucky the 521 will suddenly weaken along the path and stay weak meaning the nick is behind you so go back and do the best you can narrowing down the changeover sound and dig CAREFULLY. If you nick it digging it up, well never mind. Be patient, slow down, get low, mark well, avoid digging until all tracking options are exhausted.

    Another method but this takes practice and can work well is to trace the furthest valve after you've established a wire path. Instead of grounding the 521 to earth use the common wire as the ground. In theory the two wires being in the same ditch should nullify each other out. When you pass or get around the nick you will pick up faint sounds. This is a great method for flushing out old valves with little resistance.
    Hope this makes sense. Hands on I could teach a lot better.
    GOOD LUCK
     
  3. CAPT Stream Rotar

    CAPT Stream Rotar LawnSite Fanatic
    Posts: 5,955

    :takes notes:
     
  4. Requires cool thinking and logic helps. Also helps to be a COWBOY FAN. I understand PAT fans are totally inept at 521 usage for some reason.:confused:
     
  5. Squirter

    Squirter LawnSite Member
    from Zone 5
    Posts: 172

    Perhaps some video recording would be helpful to gain further insight.

    Go Colts!!!!!
     
  6. Either that or I can travel around the country in a RV teaching my 521 method. Turn my vacation into a tax writeoff. It is a personal method. I suspect Purp, Mike, London, Dana, Tony and many other on this site have a unique style to 521 usage. I taught Henry the nuts and bolts of using it but he has his own style now. Yesterday we were tracking a splice and Henry narrowed the area down. I yelled I'll get the fault finder. Henry quickly got his shovel and gleefully showed me he had found it before I could set the fault finder up. At times I think he has surpassed me and I HATE ADMITTING IT!:angry:
     
  7. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    Be proud of that fact, it speaks to your teaching abilities. :clapping:
     
  8. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    I only use the 521 for locating the wire path, valves (the solenoids and coiled wire wire scream at you) and finding out how deep the wire is buried. I then switch to the Ground Fault Locator and run it over the wire path that I've marked with paint. It's so sensitive that it finds even the smallest ones that have very little voltage loss. You can "tune down" the GFL and look only for large ground faults and work on them first.

    Ground faults are a lot like leaks. You can have small leaks that don't affect anything and are just a nuisance. Large leaks can disrupt the flow of voltage and stop the valve from working. A combination of small leaks can add up and create enough voltage loss that the valve won't fire.
     
  9. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    It's the best form of flattery in that you've done your job so well that Henry not only understands the basic principles he has adapted them to his own style. You should be a proud Papa. [​IMG]
     
  10. Yeah as long as he doesn't rub it in. :dizzy: :hammerhead:
     

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