IEEE Std 2740-2020 pdf free download

IEEE Std 2740-2020 pdf free download.IEEE Guide for Selection and Installation of Electrical Cables and Cable Systems in Hazardous (Classified) Locations on Oil and Gas Land Drilling Rigs.
occurs; or 2) in which hazardous concentrations of gases or vapors arc normally prevented by positive mechanical ventilation, but that might become hazardous through failure or abnormal operation of the ventilating equipment: or 3) that is adjacent to a Class I, Division I location, and to which hazardous concentration of gases or vapors might occasionally be communicated unless such communication is prevented by adequate positive-pressure ventilation from a source of clean air, and effective safeguards against ventilation failure are provided. (See NEC Article 500 and API RP 500.)
Class I, Zone 0: A Class I, Zone 0 location is a location I) in which ignitable concentrations of flammable gases or vapors are present continuously; or 2) in which ignitable concentrations of flammable gases or vapors are present for long periods of time. (See NEC Article 505 and API RP 505.)
Class I, Zone I: A Class I, Zone I location is a location I) in which ignitable concentrations of flammable gases or vapors are likely to exist under normal operating conditions: or 2) in which ignitable concentrations of flammable gases or vapors may exist frequently because of repair or maintenance operations or because of leakage; or 3) in which equipment is operated. or processes are carried on, of such a nature that equipment breakdown or faulty operations could result in the release of ignitable concentrations of flammable gases or vapors and also cause simultaneous failure of electrical equipment in a mode to cause the electrical equipment to become a source of ignition; or 4) that is adjacent to a Class 1, Zone 0 location from which ignitable concentrations of vapors could be communicated, unless communication is prevented by adequate positive-pressure ventilation from a source of clean air and effective safeguards against ventilation failure arc provided. (Sec NEC Article 505 and API RP 505.)
Class I, Zone 2: A Class I, Zone 2 location is a location I) in which ignitable concentrations of flammable gases or vapors are not likely to occur in normal operation, and if they do occur, will exist only for a short period; or 2) in which volatile flammable liquids, flammable gases, or flammable vapors are handled. processed. or used, but in which the liquids, gases. or vapors normally are confined within closed containers or closed systems from which they can escape only as a result of accidental rupture or breakdown of the containers or system. or as the result of the abnormal operation of the equipment with which the liquids or gases are handled. processed. or used; or 3) in which ignitable concentrations of flammable gases or vapors normally are prevented by positive mechanical ventilation, but which may become hazardous as the result of failure or abnormal operation of the ventilation equipment; or 4) that is adjacent to a Class I. IEEE Std 2740-2020 pdf free download.