Locating Buried Electric Lines?

[Geotech]

5 hours ago, GB_Amateur said:

Does choice of PI vs. IB matter for this?

No, either will work. You can also fake an active locator by disconnecting the wire from power and hooking up a signal generator to the wire. Set the sig gen to the same frequency as the detector and you should get a strong interference.

[Roughwater]

GB.

I had seen your post previously but didn't really know the answer so I didn't respond. But Yesterday I was out just walking around the yard checking signals as I had added a new experimental power supply for my GPX 5000. Well, I have 2 power drops from the Electric company both underground.  One to the house and one to a detached garage. So I was out by the Garage where the line goes to the meter and your post popped up in my mind. I have a Modded 5000 and I just had a older minelab 5x10 DD coil on it. Definitely not a big coil. But I could detect the line from the streen to the Garage which suprised me.  I suspect part of the reason is because it was Electrified as I have a freezer etc in the garage that is probably drawing power all the time. I don't think I could have followed it otherwise? Another possible way of locating the line would be to put a tone or signal on the power line that a detector might readily pick up? Often a line like that will run in a conduit of sorts so you might find out if it's in a conduit or not? I asked because if it is in a Conduit the line could be disconnectd at the well house and pulled back through the conduit if the conduit is not smashed. A pull cord could be attached to the wire before pulling so that a new wire could be drawn though the conduit if needed.  There is also probably a way to check the impedeance of the line per food so that if there is a break one might calculate the distance from the house the break occured. 

[GB_Amateur]

Followup:  I went out to the house where my help finding electrical lines was requested.  (As a side note, my previous communication was prior to a tornado which went through the area.  This homesite got a direct hit, but fortunately the house was spared.  Not the garage....)

The homeowner gave me more details:  from ~1965- ~1975 the home water source was an electric pump.  After that it was put on county water and apparently the pump was no longer in use.  This new homeowner (unfortunately unable to speak to the previous owner who is deceased) is interested in using the old well+pump to provide water to a garden.

She was able to determine that the electric lines from the house to the pump are in a galvanized steel conduit, but she doesn't even know where the pump is.  There is a hand pump (also no longer functioning) so the guess is that the electric pump is likely close to that.

I spent a couple hours, splitting time between the Manticore+11" coil and the White's TDI SPP + 12" Oz mono coil.  Other than noise cancel, ground balance, and gain/sens adjust I left the Manticore in my coin hunting settings (AT-General, five tones, recovery speed 4, etc.)  I was able to run the TDI with ground balance off.  What a treat that is if your ground (and swing control) allows!  Smooth threshold and very good depth.

I was specifically looking for linear targets (i.e. what a conduit would signal) and more/less ignoring localized signals other than one non-ferrous, weak hit with the M-core I thought might be the pump.  (It wasn't.)  I did find one solid (w/TDI) linear target leading away from the house where the electric lines for the pump crossed the foundation.  However, at about 10 ft from the house I lost any continuation so if it actually was the conduit I'm thinking it went deeper at that point, causing me to lose signal.  I was able to confirm with the Manticore a weak (via the signal strength indicator) signal which was showing red on the digital VDI (red ==> iron alloy).

Finally, I have another acquaintance who works for the local government tracing utility lines and he was able to give me the name and phone number of someone who does private locating.  I suggested the home owner contact him for an estimate and she said she would.

Oh, and as gratitude for my help she's given me permission to hunt her property (several acres) so I'll be taking her up on that later in the summer!

Postscript:  I now wonder if the reason I lost the signal was because that was as far as the conduit was run.  Maybe the original installers just wanted to get the lines protected near the house where most ground work activity would be and then just ran the unprotected wiring the rest of the way.

[Joe D.]

Great job and play-by-play GB! Appreciate the follow-up, and kudos for a permission! Hope you do well there!🍀👍👍

[geof_junk]

A brother in-law of mine had a 10  acres  small farm. His water was supplied with a mile long 1½ inch plastic pipe that was joined with brass connections. The easement went through another farmers property that kept stealing his water ( a large cost was charged from the waterboard was involved). In the end my brother in-law went to a large water tank supplied from his roofs. To prevent the thief from using his pipework I located all of the brass connectors which were 18" deep and he removed them all as bad blood was involved.  

[Geotech]

On 5/19/2025 at 11:25 AM, GB_Amateur said:

Postscript:  I now wonder if the reason I lost the signal was because that was as far as the conduit was run.  Maybe the original installers just wanted to get the lines protected near the house where most ground work activity would be and then just ran the unprotected wiring the rest of the way.

Normally conduit is not run the entire length, just where necessary.

Question: Can you run the TDI & Manticore at the same time and get them to strongly interfere with each other? If so, set them up for maximum interference; place the TDI coil adjacent to the power wire that goes out to the pump; then use the Manticore to trace the TDI-injected signal on the wire. This is called inductive-mode tracing. You want to orient the TDI coil like the pic below, and then also search with the Manticore coil perpendicular to the ground, also like in the pic.

 

 

[GB_Amateur]

7 hours ago, Geotech said:

Can you run the TDI & Manticore at the same time...?

I'm going out-of-town for several days but I'll try that when I get back.  Thanks!