underground fault locating

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bth0mas20

Senior Member
Location
Maryland
I attempted to locate a bad wire today with no luck.
Its a 400' run 240v with neutral and no egc. The wire is direct burry USE. Half the run is burried in sand and the other half thru a flower bed till it gets to the house panel. Alum wire. Only one conductor meggers bad. The voltage is at 60v when it reaches the sub panel at the pier.

I am using an Amprobe AT-2005 and a Ridgid Seektech SR-20 locator.
I got different results with the amprobe when I tried different methods.
Does anyone have experience in this situation that may be able to tell me how to use my locators better to find this.

All of my traces were using only the bad wire. I get a good trace the full length of the bad wire so its not an open which would be easier to find.

I looked for loss of signal and led me to different spots. I spent 2.5 hrs on it today and plan to go back tomorrow.
 

480sparky

Senior Member
Location
Iowegia
Use a special fault locator instead of a cable locator.

I use a Progressive (Now Tempo) 2003 Pulser.

It shows where the break is to within an inch.

PE2003.jpg
 

brian john

Senior Member
Location
Leesburg, VA
I use something similar to 480 by two different manufactures, when I first started I dug a 4X4 foot hole after a while I got it down to a much smaller hole. Experience with the equipment and that only comes with practice.
 

bth0mas20

Senior Member
Location
Maryland
I went back today and found the break in less than 20 mins and on my first try located it within a foot with my Amprobe AT-2005. Now I can get paid. It was a good day.
 

bth0mas20

Senior Member
Location
Maryland
The single conductor USE was burnt open with an inch gap. It was difficult to find because the frequency I was using was too high and was jumping over to the other conductors. I put my amprobe on the lowest freq and when I got to the break It droped off completly and I was within a foot. As I get better with my equipment I think Ill be able to get it closer. I would like to learn how to see the change in signal strength with my Ridgid SR-20. It will take time.
 

bth0mas20

Senior Member
Location
Maryland
I changed the two wires that meggered good to the ungrounded conductors. Then the one I spliced I uses as the grounded. The original conductor that was open was an ungrounded. So Im sure it was leaking current to ground just not enough to trip the breaker. This was mostly sand where the open was.
 

bjp_ne_elec

Senior Member
Location
Southern NH
bth0mas20 - you can actually change the frequency on the AT-2005? Didn't realize that, and I'm in the market for a circuit tracer - but that sounds like a pretty powerful feature. Don't think I ran across that fact in any of the postings.

Do you have the B2024/25 Booster, and if so, have you used it? Just wondering under what situation where it comes in handy

Thanks
 

cadpoint

Senior Member
Location
Durham, NC
So AH ... OK is this a single line item charge to use this equipment, part of the total charge of the job?

You qualify what the problem is, the problem is noted to the owner, Then you Say ?

Is this like a Big Ladder Charge , And additional charge to use this on top of your show up charge ?

Or do you just say I'll be there to fix your "Service", anything on the Truck is Game. I guess I need to read more books...:D

This Item is 1K, on sale 1.4K + - ... (new-I didn't look at used)
 

big john

Senior Member
Location
Portland, ME
I probably already know the answer to this, but... Is there a low-tech solution solution for finding a grounded phase conductor in damp soil? Would it be reasonable to use a multimeter to look for a changing voltage in the earth relative to the neutral conductor?

-John
 

480sparky

Senior Member
Location
Iowegia
big john said:
I probably already know the answer to this, but... Is there a low-tech solution solution for finding a grounded phase conductor in damp soil? Would it be reasonable to use a multimeter to look for a changing voltage in the earth relative to the neutral conductor?

-John

Fault locators work by sending high-voltage DC pulses into the conductor with a fault. As that energy is dissapated from the fault into the ground, the voltage drops. In essence, the locating (frame) end is nothing more than a specialized DC meter. If you can find a way to put a lot of DC voltage into the line, yes you could conceivably locate the fault with a standard DVM set to DC volts. But 1. I think it would take way too much time and 2. looks cheesy and unprofessional.
 

bth0mas20

Senior Member
Location
Maryland
bjp_ne_elec said:
bth0mas20 - you can actually change the frequency on the AT-2005? Didn't realize that, and I'm in the market for a circuit tracer - but that sounds like a pretty powerful feature. Don't think I ran across that fact in any of the postings.

Do you have the B2024/25 Booster, and if so, have you used it? Just wondering under what situation where it comes in handy

Thanks


This booster will come in handy when your finding a ground fault or long distances because it will start to loose signal. I did this job without it and it was 400ft of wire in the ground. It is a great tool when you start to learn how to use it.
 

bth0mas20

Senior Member
Location
Maryland
cadpoint said:
So AH ... OK is this a single line item charge to use this equipment, part of the total charge of the job?

You qualify what the problem is, the problem is noted to the owner, Then you Say ?

Is this like a Big Ladder Charge , And additional charge to use this on top of your show up charge ?

Or do you just say I'll be there to fix your "Service", anything on the Truck is Game. I guess I need to read more books...:D

This Item is 1K, on sale 1.4K + - ... (new-I didn't look at used)


The amprobe at-2005 was 1000 new and the Ridgid sr-20 that I used was $3500. Both of these tools worked well to find this fault.
I may have been wrong but I just charged 85 per hour and It took me 4.5 hrs. I felt ok with that but I may still be low. The ho didnt have any problem with it.
 
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