If all underground conduits take on water.....

[mobiledynamics]

It's my understanding no matter how tightly sealed, proper coupling connections, etc are done, all underground conduits do take on water.

? With high voltage, the jacket is rated for underground burial, etc.

With LOW voltage, same spiel, but low voltage also comes flooded with GEL compound as well to mitigate the water.

Is it due to the high voltage lines always being ~hot~ in that in drives off the moisture as opposed to the latter ?

 

[rockwithjason]

I am not sure I understand the question but I think you are asking how KV level cables survive being in water?

the cables don't actually run all that hot temperature wise. the outer jacket is designed to resist water. XLPE cable has a finite life in a conduit just as any other wire does. the cable develops what are called water trees where the water penetrates the insulation and semiconductor layers and causes mini faults called partial discharges. these partial discharges can be listened for with the right equipment and the remaining cable life can be predicted.

By low voltage I am assuming that you mean communication or signal cables. There are wet rated cables that are both filled with the pic gel you mentioned and without. The failure mode is not all that different from the KV level cables. The water eventually works thru the tiny faults in the cable insulation and trees to the outside but in this case the voltage levels are so low that they don't do much of the work in causing the degradation, it's mostly mechanical by capillary action and such.

does that answer your question?

 

[toplessHO]

only one answer for high voltage cable
Kerite

 

[sberry]

You cant ever predict which pipe will get water, how good the installer did unless you pressure tested etc, a lot of factors go in to wet locations, some don't even weather seal the pipe like poco risers up poles.
Even in sunlight and weather some of the coating last a long time. Toss one in a cool plastic pipe they are gonna last a long time, direct burial too.
Put a gallon of water in a milk jug in a closet, last years, put it in an anti freeze jug even longer and the coatings on a modern wire are way better. Even compared to electric tape, one layer +600V.
Get low v wet and short it right out. I think the messy stuff simply seals repels and leaks out any wound, prevents water migration at terminations, generally gets all over and repels moisture.

 

[sberry]

I am not sure I understand the question but I think you are asking how KV level cables survive being in water?

the cables don't actually run all that hot temperature wise. the outer jacket is designed to resist water. XLPE cable has a finite life in a conduit just as any other wire does. the cable develops what are called water trees where the water penetrates the insulation and semiconductor layers and causes mini faults called partial discharges. these partial discharges can be listened for with the right equipment and the remaining cable life can be predicted.

You bring up a good point about service life I like and its often a judgment call with a risk to reward ratio. The longer it goes the higher the risk. I am replacing 60's stuff now. I understand the undisturbed wire and the aluminum wire connections but its already old, already a long way in its service life and while some of the basics are the same they got generations of revisions to wire coatings and a ground wire for sure and in a lot of cases better installers, easier better pipe from physical protection etc.
I never use service cable, I pipe, my Dads has cable but is eve protected out of sun. Its gonna get moved during a rnovation and I aint even gonna start off on the wrong foot and save anything

 

[sberry]

Residential isn't really hi v but it shouldnt be hot.