Uf Depth

osborn

Is there a NEC for the depth of uf cable?

Speedy Petey

Only if you're burying it.

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troubleseeker

I am not an electrical contractor, so I hope one will correct if wrong, but I believe it is 18 inches.

In the real world, the required depth seems to have a general rule of thumb though... it seems to be required to always be four inches less than the depth of the trench the sprinkler guy is cutting. I never let our electrician use this stuff, PVC conduit is cheap.

Teetorbilt

I believe that 18" is the min. I always go 24" and use conduit.

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Speedy Petey

OK, I was being facetious since the question was so obscure.

The minimum cover requirements for UF cable are 18" in a residential setting, unless the circuit is GFI protected BEFORE it goes underground, then it is 12".

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mdshunk

You'd think something so fundamental as burial depths would be cut and dry, but it's complicated. I went ahead and copied the actual table from the code, because it's hard to explain without the table:

mdshunk

Sorry, Peter. I was busy scanning in the table while you replied. Didn't mean to step on your toes.

Speedy Petey

No problem at all.
The table was a good idea.

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osborn

Thanks! I better start digging. Sparkey will be here next week.

Sparky Joe

Sparky is already here

And it doesn't take more than a couple hours to dig a trench. And no mater what code says, be sure you get below the frost line to save trouble and aggravations down the road.

Speedy Petey

Are you serious??? Where I am a 40' trench can take an hour in one spot. Go 5 miles away and that 40' trench can take all day!


Again, are you SERIOUS???? I aint diggin' no 4' deep trench w/o a machine!!!!!


Joking aside, are you really serious about getting below the frost line?

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mdshunk

I can see some benefits of getting below the frost line, but not enough to where I'd ever make a ditch that low.

stars13bars2

As previously stated, if it is 120 volts or less, 20 amp max and GFCI protected it would qualify for 12" of cover but, if its not a driveway or outdoor parking area for one and two family dwellings and this used for dwelling purposes only, the general rule for UF cable would be 24" of cover.

Sparky Joe

Around here frost doesn't get below 18 inches, I can't imagine how cold it must be to get 4 feet of frost.

Our dirt must be softer out west too. I dug a 200' trench 2 feet in half a day, and that was a lot of digging.

mdshunk

Dirt's different everywhere. There's no place around me where you could dig 200' at 24" in a half a day. In mountain ground, you can't even stick 1/4 of your shovel in the ground anywhere without hitting stones. In the valley's, there's lots of shale patches where you'd need a pick to loosen it up first. You'd be lucky to get 6 feet at 24" in a half a day by hand in that stuff. Hand digging is my absolute #1 most hated task. I'm just not built for it.

Sparky Joe

I don't look forward to it either, but when the dirt is soft it's a nice way to pass the time.

The trench I mentioned was part of a brand new place so the dirt had been worked by machines several times prior to me with my shovel.

Speedy Petey

There are two small parts of my town that are loamy sand. One is old farm land, now MANY houses. The other is the heart of the village.

You could dig all day and trench around the block. You can also push a ground rod in to about 2' and use a 20oz hammer to finish it.

The rest is exactly like Marc described.

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Sparky Joe

I've done some tunneling and lots of digging at my dad's place. The city he lives in is called "Sandy"(I'll give you one guess why)
Back when this entire area was covered by the prehistoric lake Bonneville, the rivers from the canyons made a 400' thick sandbar which is now called Sandy City.
Digging over there is like a dream, though growing things is not(huge water bill in the summer)