220VAC line burial depth ?

[bcarwell]

I'm routing a 220VAC line (AWG 4, 100 amp service) underground from utility pole 125 feet to my shed for a welder with ground and neutral. I'm putting it in conduit.
Can anyone tell me how deep the conduit is supposed to be buried to be up to code ?
I live in Liberty Hill, Texas and all I've been able to find is that it is subject to the Internation Residential Code which I don't have access too. Guess I could call City Hall but I'm sure I'd waste a lot of time on hold and get the run around, and I'd like to do some diggin' tomorrow.
Isn't it supposed to be about 1 1/2 feet ?
Also, for bonus points, I started the dig today with my Kubota 7500 and a Middlebuster I bought today at Tractor Supply. But with my 3PH all the way down, the most I could dig down was about 8 inches. I looked at my 3PH linkages and all I could find is that there are two holes (a few inches apart) on each side link arm which connect to the lifting arms and that I apparently could get a little more vertical movement of the linkage arms with less leverage by picking the holes that are closer in to the tractor. But even if I do so, it doesn't look like I'd get that much more vertical movement out of the 3PH/Middlebuster.
Any tip on how to get the Middlebuster to go deeper ?
Thanks,

Bob

 

[AndyMA]

All the electrical trenches I dig around here (Conn & Mass) are 3 feet. 12" of sand is put in trench and pipe is laid on it. More sand and then marker tape before finishing burying it. The marker tape and sand on top of conduit are telltale signs to anyone digging that there is a buried conduit.

Andy

 

[jkpell]

I met with our power company yesterday and they are putting the underground in at a depth of 4'. Thats what they do here in GA.

 

[Raddad]

Michigan is 24"

 

[caver]

18" but my code book is 1990. Local code could be more strict.

 

[billbill1]

I have always thought 18" was the minimum but I'm not sure.

 

[dirtworksequip]

bcarwell, I would imagine codes vary from state to state,but I can give you this advice. Any electrical runs that I ever put in where done at 4' bury depth. The reason being at that depth it has less chance of you or someone else digging into it accidentally. Waterlines are at 3'. If there is a water break and a crew comes out to repair the line they should not have to worry about getting into the electric. Even on your own property if it were me I would go with the 4' burial depth. Over time you may forget all about that electric service and conduit you put in. (your mind on something else) At less than 4' you or someone else may dig into it accidentally. One of these days someone else will own your property and have no idea that there is a conduit just 18" under the ground. Decide they want to plant a tree and auger down 2 feet for the tree........... Why create a dangerous situation for yourself or someone else. Go with 4' and be safe. Just my thoughts on conduit burial depth.

 

[Inspector507]

Can anyone tell me how deep the conduit is supposed to be buried to be up to code ?

Bob

Codes vary from place to place, but the NEC requires 18" of cover if using PVC.

 

[Farwell]

Bob,
I like 18 inches for conduit and 24 inches for direct burial but this will vary according to your location. Check with your licensed electrician.
Suggestion, take photos of the trench for future reference and prior to digging make sure where any other utilities are located and have them marked by the utility companies even if you know where they are, this provides you some insurance in case you hit something that shouldn't be where you are digging.
David B

 

[Cliff_Johns]

Another thing you can do is bury yellow caution tape a foot higher than the wire itself. This way, when the next person starts to dig, they might see the tape before they part the cable.

Cliff