grounding old 2 wire junction to grounded junction

gm8075

My daughter just purchased an older house with a mixture of wiring. The house is a two story, with access to some of the wiring in the attic floor/2nd story ceiling. There is one circuit (circuit 1) with newer romex with a ground. The older circuit (circuit 2) is 2 conductor with no ground. I am replacing the wiring to several outlets and switches. I will put a new junction box in the attic for connection of the old and newly replaced wiring. (Hope to eventually find a way to replace the entire run from the basement.) Would it be okay (even within code) to run a separate ground from the grounded junction box (circuit 1) to this junction box (circuit 2) to supply a ground?

Just Bill

If the ground in the grounded Jbox comes from the breaker panel, yes.

AllanJ

A separate ground wire retrofitted to an existing 2 wire circuit must go all the way to the panel where that circuit has its breaker. It doesn't have to follow the original cable exactly for example it could go through a hole in the siding to the outside and be somewhat hidden among the clapboards and then down to the first floor rim joist if it is too inconvenient to fish it through the walls and floors.

Exception: If the separate ground wire first reaches a fat ground wire from the panel to a water pipe or ground rod, it can stop there.

The jury is still out on whether a separately strung ground wire, if it should first reach another separately strung ground wire, for another part of the same branch circuit, it could stop there rather than parallel the latter down to the panel, although if I had to retrofit three somewhat adjacent receptacles on the same circuit with grounds, I would not run three separate ground wires all the way to the panel.

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gm8075

I strongly believe the grounded junction box that I proposed grounding to was the one and only jbox directly from the panel, if that makes a difference.
Had a definitive yes on the original question, then another response which also makes sense. Is there a concern for degradation or something if joining the other jbox?
Thanks a lot to "Just Bill" and "AllanJ", your help is truly appreciated.