Conduit for buried electrical

[yeldogt]

My contractor always runs underground wires in conduit -- I can see how this would be wise .... is buried electrical cable that much of a problem?

I have buried single use wire -- 12g UF wire in my back yard to a single outlet or light ... never an issue. Don't utilities and developments use buried wire not in conduit?


I also think the wire to the well at one of my places runs with the water line -- not in conduit until it enters the house.

 

[Syberia]

Conduit is cheap, and ensures you won't be re-doing your trench if anything ever goes wrong. Rocks and shifting soil can break direct-bury cable much easier than they can break conduit. A couple weeks ago, a guy backed into an above-ground junction box with a Bobcat (don't ask). Broke off the conduit at the ground and snapped the wires inside.

I pulled the broken wires out, dug down a few inches, glued on a new piece of conduit, and pulled in new wires. About a 1-hour repair. Had I direct buried the wire instead, I'd be digging a new trench.

3/4" conduit is less than $2.50 for 10 feet, and adequate for most things. Use it.

 

[teamextreme]

What he said. Plus you don't have to dig as deep a trench, typically 18" vs 24".

 

[yeldogt]

I think he is running 2" for some of it .. guess it looks more expensive vs reality.

 

[Stuart in MN]

Depending on your location and the amount of local wildlife, another potential benefit of using conduit is it protects them from burrowing critters like gophers to chew on the wires. A larger conduit (like the 2" mentioned) is even more difficult for them to get a bite on it.

This is typically a pretty uncommon occurrence, but it does happen every so often.

 

[klassenl]

I have installed miles of direct burial wire. Direct burial is a legitimate and good way of doing things.

 

[rburke65]

Installed direct burial for neighbors pole barn and 9 years had to do it all over again.....in conduit thus time. Sort of Ricky soil and it wore through the insulation. 2" conduit is inexpensive. And extra 2" conduit is cheap insurance.

 

[Bert_]

In my experience, most of the time when an underground is damaged it's because the wire was hit by someone digging. The other thing that can happed is a rock or sharp object can pierce the insulation and the wire will corrode away, That is almost always caused by careless backfilling.

It seems like most people don't understand that direct buried wire can be fixed. You don't have to dig a new trench and install new wire. You just cut out the bad spot and splice in a new piece. If you don't know where the bad spot is there are locator's that will find the bad spot.

If the wire gets hit it's a lot easier to splice direct buried wire than it would be to fix conduit and get a new length of wire and re-pull the whole thing. Especially if the wire run is very long.

In the second case conduit may protect the wire, but keeping rocks out of the backfill would solve the problem also.

 

[yeldogt]

I'm very unlucky ... think conduit is a good idea. I did not understand the rock danger.

 

[FullRaceMerc]

Shoot, sometimes I run empty conduit in an open ditch even if there are no wires currently needed. It has paid off more than once. Conduit is cheap compared to digging. And having tbe ability to make changes later is worthwhile imo. Especially under concrete. I also lay warning tape above buried conduit.

The best one I can remember was at a commercial site with multiple buildings. Everything underground & concreted over 10 years before they wanted fiber optic run to a separate building. And we had an extra conduit already in place. Dig up both ends for an easy trip across. We made more profit, they spent far less, & they thought we were the best thing since sliced bread.

 

[sberry]

I have a lot of direct, 1000s of feet, never had a problem. The power co does most of theirs that way. This is before disconnects or breakers.