These requirements cover self-contained@ refrigerated vending machines intended for connection to alternating-current circuits rated 600 volts or less in accordance with the National Electrical Code@ ANSI/NFPA 70. Vending machines covered by these requirements: a) Incorporate refrigeration systems of the air-cooled or water-cooled type employing hermetic refrigerant motor-compressors; b) May be battery operated; c) May employ flammable refrigerant as defined in Requirements for Refrigerated Venders Employing a Flammable Refrigerant in the Refrigerating System@ Supplement SA; d) May employ thermoelectric chilling systems. These requirements also cover refrigerated vending machines intended for installation within motor fuel dispensing facilities in accordance with Supplement SB of this Standard: Requirements for Refrigerated Vending Machines Intended for Installation within Motor Fuel Dispensing Facilities@ and as defined by the Code for Motor Fuel Dispensing Facilities and Repair Garages@ NFPA 30A. These requirements do not cover vending machines incorporating universal motors rated at more than 250 volts@ nor vending machines which have a principal function other than storage and dispensing of refrigerated products; nor to vending stations@ that is@ freestanding stationary structures for outdoor use.