The problem(s) resulting from the Cable's Shield being connected to "Ground" at multiple points, come in the form of "Ground Loops".
Connecting the Drains to a single common "Ground" point, removes the possibility of Loop Currents being shuttled around... provided the Cables are terminated correctly.
As with most Cabling and Electronic stuff, a "COMBUS" - like what you are installing Cables for, should have "Grounding" connections terminated in a "Star" fashion (all bond at the same point).
With a "T" Tap, the tapped loop segment(s) don't bond Shields Directly to the Star Point, instead they bond kind of Vicariously via the "Trunk".
Scott35
