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Thread: Input please on this simple locate

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    Default Input please on this simple locate

    I would welcome some experienced input on this relative small, but important matter.

    I am an Exterior Contractor doing a variety or mainly residential outside projects. I have added simple locating (residential as it applies to home-projects) as one of my services recently and use a VlocPro2 by Metrotech and have got mainly reliable results finding gas, power, comms, drainage and water.

    I am gaining experience and hoping to move into Locating fulltime in the coming year as I really enjoy it and see its growing need in our area. But I am not naive to think I know any more than I do. I know there is tons to learn only through experience. To do this, I locate as frequently as possible, even if not part of the job. I also train with a Utility Contractor after-hours.

    So... wondering if I can get some input on this one aspect of a project I am on. We know absolutely for sure there is an electrical line between house and garage, then garage and shed per sketch below. I machine-dug the trenches for them 3 years ago as part of the renov. Power runs from the house panel to a smaller panel in the garage for the whole garage that serves as office. Garage/Shed line then feeds out from Garage panel to a panel in the shed. The house/garage and garage/shed lines are in fairly close proximity underground for the section approaching garage, and feed through same hole in wall.

    yard-21432.jpg

    I get a perfect signal on the house/garage line (red in sketch) to garage panel no matter what hookup I use, even induction. On my receiver, all aspects of detection work perfectly including peak/analogue reading, audio, left/right arrows, line direction indicator, and depth. Even if I do a direct by clamping the metal panel in either garage or shed, this main line (shielded cable) from house to garage lights up great per pic below...

    20160625_122322_001_27801468122_o.jpg

    Finding the garage/shed line (orange in sketch), however, is a different matter. It is a non-shielded, but UG rated line... lighter than house line, but heavy enough gauge to feed 3 outlets in garage for power tools, heat, and lights. Clamping to PANEL at either end gives unreliable reading with lots of false readings, including very strong signal in wide open area of yard where nothing is known of ... may be an old tank down there or something... (50 year old house, could be anything). Induction not practical due to space limitations on this line. Inductive clamp also weak/scattered readings. Tried numerous frequencies and grounding points. Ground is not dry... we have had steady rain since May.

    20160625_123229_27624421390_o.jpg

    So I shut main power down from house and did an exclusive and direct-connect (below) to the garage/shed line at the garage end. Beautiful detection on my Peak/Audible, decent accuracy on my Left/Right arrows, but absolutely no reading on my line direction indicator. Also, the false signals around the yard all but disappeared. Again, I know this line is down there and where it is so I know my peak is correct. And no obvious distortion. No overhead power nearby, no large metal objects.

    20160625_121626_001_27289920013_o.jpg

    20160625_122016_002_27624333030_o.jpg

    Furthermore, when I light up the garage/shed line directly and exclusively, the line to house continues to light up just as perfectly as before with all features of my receiver. So gear is working fine.

    So... what might be the source of:

    1. The scattered detection of garage/shed line when I hook up to panel or use inductive clamp on the garage/shed line itself?

    2. The limited accuracy of my left/right and absolutely nothing on my line direction indicator and depth? Could only be some factor of the line, right?
    Last edited by RanVan; June 25th, 2016 at 06:37 PM.

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    Default Re: Input please on this simple locate

    one of the plugs / lights in that last shed have shorted out and are touching each other somewhere so therefore your line will not locate out . OR that same line in the ground was struck by lighting at some point and is doing the very same thing underground and therefore will not locate out . that is my 2 cents . good luck bud .
    wise men talk because they have something to say and fools because they have to say something....plato

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    Default Re: Input please on this simple locate

    Quote Originally Posted by yahoo View Post
    one of the plugs / lights in that last shed have shorted out and are touching each other somewhere so therefore your line will not locate out . OR that same line in the ground was struck by lighting at some point and is doing the very same thing underground and therefore will not locate out . that is my 2 cents . good luck bud .
    Thanks Yahoo.... I appreciate the feedback.

    What about this approach to eliminating potential short in plug or light issues.... What if I detach garage/shed line at both panels, and do direct connect at both ends instead of grounding to the grounding rod in the soil. In other words, while wire is not attached to anything else, attach red lead to one end of target line, ground lead to other end (with grounding extension) , and locate it. Will try next time I am there and see what happens.... and report back.

    Nothing I suppose can be done if however the lightning thing happened eh?

    Thanks again.

    R
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    Default Re: Input please on this simple locate

    Disconnect the line in question at both the garage and shed completely isolating it. Then at one end put a jumper between two of the hot legs or between hot leg and insulated ground wire. next connect to the two corresponding ends at the other location. Send your signal down one leg and back up the other without connecting to a ground rod driven into the earth. This will give you a signal only one the circuit you are tracing with no bleed over onto anything else.

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    Default Re: Input please on this simple locate

    Quote Originally Posted by ProfessionalLocator View Post
    Disconnect the line in question at both the garage and shed completely isolating it. Then at one end put a jumper between two of the hot legs or between hot leg and insulated ground wire. next connect to the two corresponding ends at the other location. Send your signal down one leg and back up the other without connecting to a ground rod driven into the earth. This will give you a signal only one the circuit you are tracing with no bleed over onto anything else.
    Thanks ProfLocator.... will try follow this next time on site. May have question yet. Appreciate it.

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    Default Re: Input please on this simple locate

    Quote Originally Posted by RanVan View Post
    Thanks ProfLocator.... will try follow this next time on site. May have question yet. Appreciate it.
    Should work. This technique is not available to one call locators.

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    Default Re: Input please on this simple locate

    Quote Originally Posted by ProfessionalLocator View Post
    Should work. This technique is not available to one call locators.
    Thanks ProfLoc and Yahoo....

    Ok, so I isolated the garage/shed line..... detached white/black at shed sub panel by detaching from busbar/lug accordingly, then jumped them together. I then detached at similarly at garage panel and hooked up my transmitter as suggested. Results were noticeably better, but still not getting readings on my left/right, line direction indicator, or depth.

    I did however get a great peak. Very narrow and no false readings around the yard like before. Also, house/garage line did not light up at all, so circuit is truly isolated from it.

    Here is how things looked...

    20160626_084432_27328073874_o.jpg

    20160626_182050_27327007083_o.jpg

    Strong peak over target...

    20160626_183029_27661355160_o.jpg

    Left/right were off peak...

    20160626_183049_27327611304_o.jpg


    I will check with Metrotech on this. I can't imagine it being problem with gear as have not experienced before. Yahoo poses the lightning-strike question. Not sure how to evaluate that.

    I did keep ground (bare copper) connected at panels so maybe should try without?

    In the end, this job is nothing to worry about because we have located cable. But principle trying to come to grips with.

    Line damage not likely as area is inactive.... no other digging happend since install. And electrical in shed never a problem.

    Any further thoughts? Thanks again.

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    Mke
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    Default Re: Input please on this simple locate

    I have a couple of questions...

    Did you only use 65Mhz for your frequency?

    What type of wiring did you use to run to the shed?

    PL's idea should do the trick. Some locators don't have enough cable to run a jumper. I was curious if you tried a higher frequency. 83mhz? Depending on the wire it could do the trick. Also, what all is in the shed? I know some well houses have the infamous VSP. The Variable speed pumps tend to negate any tone in the electrical cable feeding the pump. The only way to locate the wire is to shut the pump down.

    The only other issue I could see is if the conductors running to the shed are twisted inside of the insulation. Typically Romex won't do that, but some other multi conductor cables can twist inside the insulation. this makes it a bit more difficult when looking for the route.

    mke
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    Default Re: Input please on this simple locate

    Thanks MKE..... will answer your Q's individually...


    Quote Originally Posted by Mke View Post
    I have a couple of questions...

    Did you only use 65Mhz for your frequency?

    No, I don't think I went that high.... but could try it. Varied 512 Hz to maybe 83kHz range. Again, could try higher.


    Quote Originally Posted by Mke View Post
    What type of wiring did you use to run to the shed?
    Couldn't read it on the wire itself, but pretty sure but definitely 2-wire (insulated black, insulated white, bare ground).... definitely UG rated and pretty sure is 14 gage. No conduit or shield.

    Quote Originally Posted by Mke View Post
    Also, what all is in the shed? I know some well houses have the infamous VSP. The Variable speed pumps tend to negate any tone in the electrical cable feeding the pump. The only way to locate the wire is to shut the pump down.
    No, nothing running in shed. Mainly storage. Definitely no pumps.



    Quote Originally Posted by Mke View Post
    The only other issue I could see is if the conductors running to the shed are twisted inside of the insulation. Typically Romex won't do that, but some other multi conductor cables can twist inside the insulation. this makes it a bit more difficult when looking for the route.
    Visually, it is a cable like the pic.... I can't see opportunity for twisting.... but can't verify ... I know the electrician put it in, will see if can check with him.

    ug-14-2.jpg


    I did follow PL's suggestion per below. Readings improved but still some uncertainties. Hope to get to bottom of it to help me know for other locates.

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    Default Re: Input please on this simple locate

    Greetings RanVan! Welcome to the CableVine!

    I have done many locates as a favor for homeowners on their private lines between out-buildings.

    My transmitter leads have the standard bull-nose alligator clip on one lead and an AST Labs Alligator Clip Bed-of-Nail and Single Spike Angled Nose clip on the other lead.


    AST Labs Alligator Clip


    I simply poke the nose clip into the ground hole of a wall socket and ground out my bull nose clip in the dirt.




    F8 frequency usually gets the private duplex wires to locate easily.





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    Default Re: Input please on this simple locate

    Thanks Wingfoot. Sounds simple enough. I was thinking of buying Vivax's Live Plug connector but going in through the ground hole sounds simpler... and cheaper by like $300. Everything our parents told us never to do growing up.... shoving metal into sockets.... turns out can be a good idea after all?

    Ever try that technique and find out that the outlet was mis-wired, or that there was some current-leak from neutral?
    Last edited by RanVan; June 29th, 2016 at 01:53 AM.

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    Default Re: Input please on this simple locate

    Quote Originally Posted by RanVan View Post
    Thanks Wingfoot. Everything our parents told us never to do growing up.... shoving metal into sockets.... turns out can be a good idea after all?

    Ever try that technique and find out that the outlet was mis-wired, or that there was some current-leak from neutral?
    Greetings RanVan! That would never happen. If the ground was ever mis-wired, there would be an instant short in the system when it was initially wired; red hot wires with melted wire insulation would pursue ending in a structure fire. If the out-building you are wanting to complete a locate on is not consumed in flames, feel safe in poking the ground hole................ just sayin.'


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    Mke
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    Default Re: Input please on this simple locate

    I've shoved my fair share of metal objects into the ground of an outlet and never have been shocked. What does happen is an improper wiring and the ground wire not connected at all in some part of the line. This happens more then you think. Most locates I do inside of buildings I start off by shoving my leatherman into the ground and clipping to that.

    mke
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    Default Re: Input please on this simple locate

    Quote Originally Posted by Mke View Post
    I've shoved my fair share of metal objects into the ground of an outlet and never have been shocked. What does happen is an improper wiring and the ground wire not connected at all in some part of the line. This happens more then you think. Most locates I do inside of buildings I start off by shoving my leatherman into the ground and clipping to that.

    mke
    Thanks MKE.

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    Default Re: Input please on this simple locate

    Wingfoot...

    So this not likely to happen?....
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