Somewhat related to a recent post regarding RCA cable runs in walls, I was wondering what guidelines others follow when running low voltage signals in close proximity to AC. I know it is preferable to separate them, but I have an application where I need to run them together. I was planning to enclose the two sets of wires in separate steel channels. Would this provide adequate shielding?

Thanks

Don't think so, the magnetic fields may still induce noise on the unbalanced lines....

I would really suggest looking to balance the lines or use Cat 5. Those convertors are really reasonable these days.

How long a run is it.

Usually enclosing both line AC and other low voltage cables in separate grounded steel conduit is adequate.
Try to keep the conduits physically separated if possible. This method is frequently used to separate AC lines from unshielded computer cat5 cables in commercial installations. You don't exactly say what your low voltage lines are carrying.