Electrical Mystery

[grsthegreat]

Ya, thing about direct bury wire its supposed to go 24” under the surface. But most people kinda cheat on this.

 

[CliffordK]

Do you have this circuit daisy chained with several items hooked together? Some working and some not working?
If so, that would certainly help you isolate where the problem is. For electrical outlet and switches, I have been disappointed with the old punch down style connections. I always screw down my connections or use wire nuts.

On vehicles it is solder and shrink wrap.

 

[LittleBill21]

I'm thinking about the wire being damaged, I'm remembering that my wife dug up the area where the line was to save some of her plants from the dogs. After installing the line, we decided that we needed another dog run, so I fenced in an area of the yard that went through her shade garden. Once the dogs where in there, the plants started to die, and she is borde line psychotic about her plants, so she dug them up to save them. We're pretty sure that she damaged the wire. That narrows down where I need to look for the damage, and where I'll start digging when things warm up again.

What I didn't know, and I still don't understand, is how a damaged wire can reduce the voltage in half? I thought that if it's broke, it's not working. If it's exposed to the soil, it's shorting out and tripping the breaker.

follow the steps i mentioned above. although likely, you haven't yet proven the wire is bad. the other testing will take less then 10 minutes. i strongly recommend you follow it

to understand the damage wire issue. watch this video. yes its for car's and dc, but its the same principle

 

[ponytug]

How much is this type locator?

New? Thousands to high tens of thousands. A great deal depends on features such as whether the device can just trace versus determine depth or diagnose faults or advanced features like determining the distance from a single point to a fault (TDR), and how deep it can work.

Used? Several hundred to thousands depending on the make, model, and features. I don't use it often, so I can afford to walk a cable to find a fault, so I don't need TDR type features, and I'm not working in an urban street trying to find a cable 15' down amidst other cables, pipes, and obstructions. Horses for courses.

For me, for doing things like regrading driveways or digging, it is a great tool to have, as there is a big difference between "yeah, there's a power line from point A to B", and "knowing exactly" where the power line is and how deep it is. The same sort of difference for discovering that you have a partial break in a wire like @EddieWalker, and knowing that the bad point is 67' along the cable and 15" down. That's a lot less digging in the second case. For me, it has been money very well spent. While one can splice a 4ga wire underground to make a repair, I personally don't expect the same reliability of spliced cables as I do of unspliced cables, though I know companies who make splices assert otherwise. I do think splices are a cost effective solution, but not as reliable as new cables ($$$). So, I try hard to avoid cutting underground cables.

YMMV.

All the best,

Peter

 

[EddieWalker]

I dug the trench for the wire from my house to the first fence post with my trencher. Depth is around a foot. That' run is about 100 feet. I have a junction box at that fence post. From there I ran the line to the light post that I'm dealing with. There is another line in there that will go to another light post, but I'm procrastinating as long as possible on getting that done. And there is another line that will go to the vegetable garden so I can install an outlet to control sprinklers one of these days. It's all grey direct buried 12/2 on a 20-amp breaker.

From that post to the tall light post, the wire is probably six inches deep. It's around 150 feet in distance. I dug that with a shovel, by hand, over a period of several weeks, a few years after the first line was installed.

My plans evolved over time, and that run to the light post is because I made a huge error and said what I was thinking out loud. And my wife heard me!!! Once I give her an idea that she likes, she becomes obsessed with me getting it done. If I had never said anything, I wouldn't be dealing with this stupid light!!!

Funny thing, the shallow run is fine, the deeper line is where I believe the problem exists.

 

[ponytug]

I dug the trench for the wire from my house to the first fence post with my trencher. Depth is around a foot. That' run is about 100 feet. I have a junction box at that fence post. From there I ran the line to the light post that I'm dealing with. There is another line in there that will go to another light post, but I'm procrastinating as long as possible on getting that done. And there is another line that will go to the vegetable garden so I can install an outlet to control sprinklers one of these days. It's all grey direct buried 12/2 on a 20-amp breaker.

From that post to the tall light post, the wire is probably six inches deep. It's around 150 feet in distance. I dug that with a shovel, by hand, over a period of several weeks, a few years after the first line was installed.

My plans evolved over time, and that run to the light post is because I made a huge error and said what I was thinking out loud. And my wife heard me!!! Once I give her an idea that she likes, she becomes obsessed with me getting it done. If I had never said anything, I wouldn't be dealing with this stupid light!!!

Funny thing, the shallow run is fine, the deeper line is where I believe the problem exists.

Personally, I would abandon your existing cable and run a new 12/3 cable with a GFCI breaker. Your plans include water and electricity, and I would consider that a GFCI breaker would be more than prudent. Again, personally, you are running this circuit in an area likely to be disturbed again in the future, so I would run wires in a conduit if it were me.

FWIW: I think that code in many areas for a single 20A GFCI circuit is at least 12", 24" if you don't use a GFCI breaker.

(Have you installed a whole house surge protector?)

Stay safe out there!

All the best,

Peter

 

[KWentling]

follow the steps i mentioned above. although likely, you haven't yet proven the wire is bad. the other testing will take less then 10 minutes. i strongly recommend you follow it

to understand the damage wire issue. watch this video. yes its for car's and dc, but its the same principle

That is a good video. Watched it a week ago or so. Absolutely the best way to test in my opinion. Everyone who owns a meter should watch this and learn. Quick easy way to pinpoint a problem.

 

[LouNY]

Also, the insulation can be just abraded enough to provide a high resistance to ground. Especially in dry ground. If the insulation has deteriorated enough to only have a 60 volt dielectric valve you a circuit can bleed to the actual ground and never trip a breaker if the resistance remains high enough.

New? Thousands to high tens of thousands. A great deal depends on features such as whether the device can just trace versus determine depth or diagnose faults or advanced features like determining the distance from a single point to a fault (TDR), and how deep it can work.

Used? Several hundred to thousands depending on the make, model, and features. I don't use it often, so I can afford to walk a cable to find a fault, so I don't need TDR type features, and I'm not working in an urban street trying to find a cable 15' down amidst other cables, pipes, and obstructions. Horses for courses.

For me, for doing things like regrading driveways or digging, it is a great tool to have, as there is a big difference between "yeah, there's a power line from point A to B", and "knowing exactly" where the power line is and how deep it is. The same sort of difference for discovering that you have a partial break in a wire like @EddieWalker, and knowing that the bad point is 67' along the cable and 15" down. That's a lot less digging in the second case. For me, it has been money very well spent. While one can splice a 4ga wire underground to make a repair, I personally don't expect the same reliability of spliced cables as I do of unspliced cables, though I know companies who make splices assert otherwise. I do think splices are a cost effective solution, but not as reliable as new cables ($$$). So, I try hard to avoid cutting underground cables.

YMMV.

All the best,

Peter

Not anymore there are numerous different wire locators for $35 to $200 as well as the $1500 to $4500 ones.

 

[quicksandfarmer]

as expected.

plan of action

go to the box on the fence post and do the exact same thing.

check voltage.
check wiring
attach bulb
bright or dim
same voltage with bulb lit?

if bulb is bright and voltage is stable at 118 etc. you have a problem with the connection or wire, from the fence to the lower section of the pole. strip the wiring back on both sides about an inch, make sure its shiny copper and use new wire terminals

if voltage/bulb is doing same thing.

then go to the breaker panel, check the breaker is fully seated, and the wiring is tight.
flip breaker on and off fully 3 times, retest.

if still dim

check voltage at the screw terminal on the breaker, with bulb lit, if still low, replace breaker,

if good, you have a issue with the wire between breaker and fence post.

This. If the problem is a bad connection somewhere, each time you open up a box and check it, if it works go to the end and check again. You may have fixed the bad connection by opening the box and taking the wire nuts off and putting them on again.

If you have multiple junction boxes between the panel and the light, start testing at the middle. If it works, test toward the end, if it doesn't test toward the panel. That cuts down on the number of tests you have to make.

I would think a bad connection somewhere is more likely than a damaged wire. A bad connection would mean higher resistance, which would lead to voltage drop. It's hard to imagine a damaged wire leading to higher resistance. I guess if the neutral is severed and touching the ground to complete the circuit that way you may see lower voltage.

 

[thclimer]

If I had to guess, I would think its a bad connection somewhere or a bad circuit breaker.

My experience with direct burial wire is the outer jacket material is pretty tough. If all your wife was using to dig was a shovel, I'd find it less likely that the wire was damaged under ground. Maybe if the wire was against a rock while the shovel was being scraped across it many times, but that jacket is tough. I always have difficulty stripping that jacket off to get to the wires for my connections.

Do you have a lot of sharp rocks in your ground?

I'm leaning towards the wire not being the issue.