Hi everyone,
Sorry to resurect an old thread, but I had to relate this.
We had an electrician out. He told us this wire was likely for a
planned addition and this would be for a feeder to the addition's sub
panel. Confused, I said to him "but we have only 3 conductors, and no
ground?" To this he replied:

"It is common practice to ground the sub panel AT the subpanel, there
is no need to run a ground from the main breaker box. This also saves
copper."

So ... Is this indeed common practice/code?

G