underground cable through drain?

[wantacoe]

I have a water problem in front of my pole barn. I am thinking of digging down to clay and filling in with river rock. Question is, can I run underground power cable through the rocks, maybe use a length of pcv to protect it. But in very wet times the pvc would be full of water. Acceptable or do I need to run an extra 50' of cable to go around it?

 

[wyliesdiesels]

NEVER run cable through rocks.

Put it in conduit the whole way panel to panel to avoid problems.

 

[rlitman]

NEVER run cable through rocks.

Put it in conduit the whole way panel to panel to avoid problems.

And put a layer of sand around the conduit.

 

[wantacoe]

NEVER run cable through rocks.

Put it in conduit the whole way panel to panel to avoid problems.

Is it ok to run the conduit through the rocks?

 

[sberry]

It's the only way.

 

[rlitman]

It's the only way.

As in, you can't run DB wire through the rocks. However, rocks can damage conduit too. Especially if it's above the frost line. Since you'll be digging down to clay, I suggest you place the conduit on the clay, cover it with a small amount of sand, and then backfill with the rocks. It may place the conduit deeper than required, but that shouldn't be a problem.

Anyway, the PVC being full of water is not a concern. In fact, it is to be expected.

 

[pattenp]

Power cable needs to have at least 18" of cover if in PVC conduit. If it's 120V and 20A or less, depth is 12" but needs GFCI protection at source.

 

[alfredeneuman]

Anyway, the PVC being full of water is not a concern. In fact, it is to be expected.

If it wasn't full of water, the it would have a tendency to float, which would present a whole different set of problems.

 

[mm08822]

When installing a French drain, filter fabric is needed to prevent silt from eventually migrating into the rock voids and ultimately defeating the purpose. So as for adding sand around a cable/conduit within the midst of a French drain would be wrong for the drain aspect and the cable/conduit would still be subject to a lot of damage.

Unprotected cable should not be used in rocky soil. If you must use cable, I suggest you lay it below the French drain with sand above/below it and then add the filter fabric lining the trench before the river rock backfill is added. Better yet is to use schedule 80 conduit with individual conductors pulled in it if the conduit must be within the rocky fill. Sched 80 for certain if vehicle traffic is above it. Best is to keep the conduit away from all rocks/gravel.