I would like to make two points here first.
#1: This systems is not an Article 700 system.
#2: These conductors are not Article 225 circuits.
Now, for specific questions you asked:
You asked "If I backfeed a dwelling with a optional automatic stand-by power from a permanently installed outdoor generator set, do I need to hit a building disconnecting means before the automatic transfer equipment?" See Article 230.72. This allows you to have a remotely located disconnect (such as on the genset).
You asked "Is it necessary to install audible and visual signal devices as mentioned in 702.7 with a permanently installed outdoor generator set?" Your transfer switch should have these devices installed, so you probably won't have to worry about it.
You asked "The service conductors will hit the service disconnect before the ATS...is the ATS bonding allowed through the grounded conductor with this arrangement?" The answer would be no, since the service equipment would stop at the main disconeect. A seperate equipment grounding conductor would have to be run from the disco to the ATS, and all grounding electrode connections would be made in the disco. Another option would be to run both systems into the ATS, then to the disco, after the ATS. Then you would not have to run the EGC between the ATS & disco, as your grounded circuit conductor would suffice.
Ron was correct in his statement that the ATS needs to be service rated (if installed before the disco). His reference to Article 225 is incorrect, as this is a Article 230 issue. His statement about the switching of the neutral in the ATS is also incorrect, as this is not a seperately derived system (see definitions). The determining factor for a seperatly derived system is not that there is a solidly grounded conductor, but instead that there is NO interconnection.
Rick
