The FPN of the 2002 NEC Handbook 517.30 (C)(3) discusses requirements of metal raceways for the emergency system of health care facilities. The note states "emergency system circuits CAN include services, feeders, and branch circuits". I am trying to figure out if the secondary service conductors from the utility padmount transformer to the service disconnect switchboard can be installed in PVC conduit or is required to be in metal conduit. The word "CAN" is confusing because all branch circuits in a facility would seem to have feeders and a service?