Ground wire separate from direct burial wires ?

[Stevenfyeager]

A homeowner trenched and ran a 3 wire direct burial 4/0,4/0,2/0 line to a barn. Instead of a 4 wire, they ran a separate #6 Cu wire in a 1/2 " pvc the entire distance in the trench. Not sure why they didn't run a 4 wire, it would have been a lot easier. Is it acceptable to have the ground separate ? Thanks.

 

[Little Bill]

This topic has been asked in another thread by the OP. Please reply in that thread to avoid confusion with multiple threads.
See here: https://forums.mikeholt.com/threads/ground-rods-needed-at-sub-panel.2567910/#post-2756815