Q: For a residential ground mounts which has an inverter mounted “on the building,” would 690.12 apply?

A: Typically, ground mount arrays are not subject to the requirement of rapid shutdown due to none of the PV system circuits or components contact the building.  NEC 2014 690.12 applies to PV system on a building. If PV system circuits from a ground-mounted PV array run along or enter a building the requirements of NEC 690.12 should apply.  Interpretations of the code article vary from one location to the next and a conversation with your local AHJ should be started to prevent any confusion.