Dana1028,
Exactly the point, UL does not list them for grounding purposes, never did, at least for a long time. Article 250 supports bonding around all weak points, and that is why they also must be bonded around, which is the 2nd point.
Soares quotes an IEEE testing procedure, and that is acceptable not only for enforcement with USBC standards, but NFPA documents as well. It was not enforced around here for a long time, but did finally catch up with us.
