I have a service drop 50’ from my cabin. 2 runs of 1/0 aluminum underground wire (3 wire system) were run underground in 2” PVC conduit pulled in to a junction box and then one run was wired into the the main panel which in reality is a sub panel.
There is no ground wire back to the service drop which has the meter base and 2 100A breakers (one of which is powering the sub panel), along with a grounding electrode(2) system. I am only using one run since plans have changed.
It’s too much work to pull out the 2 runs of wire to pull in a ground wire. Can I use one of the wires from the abandoned run as a ground for the new panel since it has no ground back to the service drop?
So my question is basically, can I use an aluminum conductor as a ground wire back to the drop?