Can I run direct burial line in a conduit from the ground to the electrical box?
&quot;Direct burial&quot; means that the cable is rated to be in direct contact with the ground and keep the ground water away from the wires inside. It does not mean that it is only to be used in direct contact with dirt.
Feel free to wire your whole house with direct burial cable if you'd like, just be prepared to pay through the nose for it. (Just be sure to use wire also designated RHH/RHW-2 to do this - it's flame retardant and approved for indoor use. It must be used even if running in conduit.)
Long way of saying &quot;yes&quot;, feel free to put it in a conduit as it comes out of the ground and makes its run to wherever you're terminating it. Actually, unless it's coming directly into a building, you'll be required by code to run it in conduit to protect it. Just make sure that your outdoor junction box is properly watertight.