1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULFEBRUARY 23, 20181UL 2874Outline of Investigation for Electric Motors for Use in Hazardous(Classified) Locations - Protection by Pressurized Atmosphere Maintainedabove the UFLIssue Number: 2Febru
2、ary 23, 2018Summary of TopicsThis second issue of the Outline of Investigation for Electric Motors forUse in Hazardous (Classified) Locations - Protection by PressurizedAtmosphere Maintained above the UFL, UL 2874, covers the explosionprotection of electric motors as permitted by the national Electr
3、ical Code,NEC , Article 501.125 (A)(4) by means of submerging in a liquid that isflammable only when vaporized and mixed with air, or is submerged ina gas or vapor at a pressure greater than atmospheric that is either notflammable or is flammable only when mixed with air.These requirements cover mac
4、hines rated 1000 V or less and machinesrated greater than 1000 V.ULs Outlines of Investigation are copyrighted by UL. Neither a printed norelectronic copy of an Outline of Investigation should be altered in any way. All ofULs Outlines of Investigation and all copyrights, ownerships, and rights regar
5、dingthose Outlines of Investigation shall remain the sole and exclusive property of UL.COPYRIGHT 2018 UL LLCUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULFEBRUARY 23, 2018UL 28742No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR
6、 FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTSINTRODUCTION1 Scope .42 Components 43 Units of Measurement .54 Undated References 5CONSTRUCTION5 General 56 Motor Explosion Protection by Purging and Pressurization .67 Equipment Explosion Protection by Immersion .78 Controls and
7、 Instrumentation .7TESTING9 Motor and Accessories 810 Refrigeration Compressor and Accessories .811 Over Pressure .812 Control .8MARKING AND INSTRUCTIONS13 General .814 Operating Manual 9BIBLIOGRAPHYFEBRUARY 23, 2018 UL 2874 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBU
8、TION WITHOUT PERMISSION FROM ULINTRODUCTION1 Scope1.1 These requirements cover electric motors, refrigeration compressors and accessories for installationand use in Class I, Division 1 or Division 2 hazardous (classified) locations, in accordance with theNational Electrical Code, NFPA 70.1.2 These r
9、equirements cover electric motors, refrigeration compressors and accessories as follows:a) rated greater than 1000 V and of a type designed to be continuously submerged in a fluidat a pressure greater than atmospheric that is either not flammable, or flammable only whenvaporized and mixed with air,
10、and which is for use only in industrial establishments withrestricted public access, where the conditions of maintenance and supervision ensure that onlyqualified persons service the installation.b) rated less than or equal to 1000 V and of a type designed to be continuously submerged ina fluid at a
11、 pressure greater than atmospheric that is either not flammable, or flammable onlywhen vaporized and mixed with air.1.3 These requirements anticipate common flammable gases, gas mixtures or flammable liquids withsignificant margin between the upper flammable limit and the purged and pressurized stat
12、e of use for themotor.2 Components2.1 Except as indicated in 2.2, a component of a product covered by this outline shall comply with therequirements for that component.2.2 A component is not required to comply with a specific requirement that:a) Involves a feature or characteristic not required in t
13、he application of the component in theproduct covered by this outline; orb) Is superseded by a requirement in this outline.2.3 A component shall be used in accordance with its rating established for the intended conditions ofuse.2.4 Specific components are incomplete in construction features or rest
14、ricted in performance capabilities.Such components are intended for use only under limited conditions, such as certain temperatures notexceeding specified limits, and shall be used only under those specific conditions.FEBRUARY 23, 2018UL 28744UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPROD
15、UCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL3 Units of Measurement3.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory orapproximate information.4 Undated References4.1 Any undated reference to a code or standard appearing in the requirements of this o
16、utline shall beinterpreted as referring to the latest edition of that code or standard.CONSTRUCTION5 General5.1 The control means, manual or automatic, shall be so arranged as to prevent energizing the equipmentuntil it has been purged with the fluid to exclude air as described in 6.1 7.1.5.2 The co
17、ntrol means shall be so arranged to automatically de-energize the equipment when the supplyof fluid fails or the pressure is reduced to a pre-set minimum pressure above atmospheric pressure. Theminimum preset pressure shall be not less than 25 Pa (0.1 inches water column).5.3 The equipment for monit
18、oring the presence of the flammable fluid shall comply with permittedexplosion protection requirements for the Classification of the area in which it is located and be calibratedfor the gases that are present.5.4 Pressurized parts of the equipment shall be compatible with the fluid in which it is in
19、 contact.5.5 For equipment rater greater than 1000 V, materials of construction for pressurized casings shallcomply with the requirements found in API 617.5.6 Electrical connections at the interface with the pressurized flammable gas containment shall complywith UL 122701.5.7 The motor and accessori
20、es shall comply with the applicable construction requirements in theStandard for Rotating Electrical Machines General Requirements, UL 1004-1 and applicable subparts,or IEC 60034-1 and subparts, or the Standard for Electric Motors and Generators for Use in HazardousLocations, UL 674 or Outline of In
21、vestigation Electric Motors and Generators for Use in Class I, Division2, Class I, Zone 2, Class II, Division 2 and Zone 22 Hazardous (Classified) Locations, UL 1836 as isappropriate.5.8 The refrigeration compressor and accessories shall comply with the applicable constructionrequirements in the Sta
22、ndard for Household and Similar Electrical Appliances, Part 2: ParticularRequirements for Motor-Compressors, UL 60335-2-34 and with the Standard for Safety of Household andSimilar Electrical Appliances, Part 1: General Requirements UL 60335-1.5.9 The installation and use shall comply with the Nation
23、al Electrical Code, NFPA 70.FEBRUARY 23, 2018 UL 2874 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL6 Motor Explosion Protection by Purging and Pressurization6.1 The motor control circuit shall be so arranged as to prevent energizing the mo
24、tor until it has beenpurged with the gas to exclude air.6.2 The motor shall be permitted to be used in a closed-loop such as in a refrigeration cycle or in an openline e.g. a natural gas pipeline.6.3 At startup, all air must be removed from the system before power is supplied to the motor, followedb
25、y pressurization to not less than 25 Pa (0.1 inch water column).6.4 Displacing the air can be achieved as follows:a) By continuous purging of not less than ten volumes through the motor; orb) By purging with an inert material such as nitrogen before introducing flammable gas; orc) By evacuation to 0
26、 Pa in a closed system, followed by the introduction of the flammablegas; ord) By cyclical over pressurization and release of pressure of the flammable gas, to not lessthan 25 Pa, so as to reduce the air fraction of the total gas volume to less than 1% by volume.6.5 Following the purging of air, the
27、 motor shall be maintained at a positive pressure not less than 25 Paabove atmospheric pressure.6.6 A means shall be provided to continuously monitor the pressurization and remove power if pressurefalls below 25 Pa above atmospheric pressure. Functional safety systems shall comply with ANSIstandards
28、 for assessment of functional safety systems.6.7 These requirements anticipate common flammable gases or gas mixtures with significant marginbetween the upper flammable limit and the purged and the pressurized state of use for the motor. Forexample, the 15% by volume UFL for methane permits a signif
29、icant safety margin when used at 90% orgreater gas mixtures. Conversely, hydrogen with a UFL of 75% by volume will result in a significantly lowermargin of safety at the same use concentration. The user is cautioned to have controls in place with setpoints that reflect the potential risk of ignition
30、 for the flammable material involved.6.8 LFL and UFL values are defined in IEC 60079-20-1 and in NFPA 497 which also includes a table ofvalues.FEBRUARY 23, 2018UL 28746UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL7 Equipment Explosion Prote
31、ction by Immersion7.1 The motor and accessories shall be permitted to be installed within a vessel, tank, or othercontainment means for the fluid.7.2 The control means shall be so arranged as to prevent energizing the equipment until it has beenpurged with the fluid to exclude air.7.3 At startup, al
32、l air must be removed from the containment means before power is supplied to theequipment. The control means shall be so arranged that the power is automatically removed from theequipment at a predetermined level above the equipment to ensure that a flammable mixture can neverbe attained with power
33、applied.7.4 Displacing the air can be achieved as follows:a) By continuous purging of not less than ten volumes of fluid through the motor; orb) By purging with an inert material such as nitrogen before introducing the fluid; orc) By evacuation to 0 Pa in a closed system, followed by the introductio
34、n of the fluid; ord) By total immersion below the volume of liquid contained within a vessel.7.5 Following the purging of air, the equipment shall be maintained at a positive pressure aboveatmospheric or totally immersed beneath a predetermined level of fluid. The vapor pressure of the fluidshall be
35、 permitted to be the source of positive pressure when the conditions of use ensure the absenceof air under all conditions.7.6 A means shall be provided to continuously monitor the pressurization or immersion and automaticallyremove power if pressure falls to within 25 Pa above atmospheric pressure o
36、r the immersion depth fallsbelow a pre-determined level, whichever means is applicable.8 Controls and Instrumentation8.1 For equipment rated greater than 1000 V, control and instrumentation shall be verified to comply withthe applicable requirements found in API 617.8.2 Functional safety, if relied
37、upon, shall comply with the applicable requirements in the UL Category forEnergy and Industrial Systems Certified for Functional Safety, (FSPC).FEBRUARY 23, 2018 UL 2874 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULTESTING9 Motor and Acces
38、sories9.1 The motor and accessories shall comply with the applicable testing requirements in the Standard forRotating Electrical Machines - General Requirements, UL 1004-1 and applicable subparts, or IEC 60034-1and subparts, or the Standard for Electric Motors and Generators for Use in Hazardous Loc
39、ations, UL 674or Outline of Investigation for Electric Motors and Generators for Use in Class I, Division 2, Class I, Zone2, Class II, Division 2 and Zone 22 Hazardous (Classified) Locations, UL 1836 as is appropriate.10 Refrigeration Compressor and Accessories10.1 The refrigeration compressor and a
40、ccessories shall comply with the applicable testing requirementsin the Standard for Household and Similar Electrical Appliances, Part 2: Particular Requirements forMotor-Compressors, UL 60335-2-34 , and with the Standard for Safety of Household and Similar ElectricalAppliances, Part 1: General Requi
41、rements, UL 60335-1.11 Over Pressure11.1 For equipment rated greater than 1000 V, pressure containing parts shall be verified to comply withthe applicable requirements found in API 617.12 Control12.1 For equipment rated greater than 1000 V, control shall be verified to comply with the applicablerequ
42、irements found in API 617.MARKING AND INSTRUCTIONS13 General13.1 A metal nameplate bearing the manufacturers name, the type or model number assigned the motor,together with its electrical ratings in voltage, current, horsepower, insulation system class, ambienttemperature, frequency, speed, number o
43、f phases, date code and temperature class.13.2 The motor compartment shall be marked as follows: WARNING PRESSURIZED MOTORENCLOSURE THIS ENCLOSURE MUST NOT BE OPENED UNTIL THE PRESSURE IS REDUCEDTO ATMOSPHERIC PRESSURE, POWER HAS BEEN REMOVED AND THE PRESSURIZATION FLUIDHAS BEEN ISOLATED. DO NOT RES
44、TORE POWER UNTIL THE PURGING AND PRESSURIZATIONOPERATION IS COMPLETE. SEE OPERATING MANUAL NO. _.13.3 The equipment is permitted to be marked for use in Class I, Division 2, or Class I, Zone 1, or ClassI, Zone 2 in addition to or in place of Class I, Division 1.FEBRUARY 23, 2018UL 28748UL COPYRIGHTE
45、D MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL14 Operating Manual14.1 A manual detailing the startup, control, use, and safe shutdown procedures shall be provided. Forequipment rated greater than 1000 V, this manual shall be in accordance with API 617.FE
46、BRUARY 23, 2018 UL 2874 9UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULFEBRUARY 23, 2018UL 287410No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULBIBLIOGRAPHYThe sta
47、ndards listed below are used for evaluation of components and features of products covered bythis outline. These standards are considered to refer to the latest edition and all amendments publishedto that edition.ANSI/ISA-12.27.01 Requirements for Process Sealing Between Electrical Systems and Flamm
48、able orCombustible Process FluidsAPI 617 Axial and Centrifugal Compressors and Expander-compressors for Petroleum, Chemical and GasIndustry ServicesIEC 60034-1 Rotating electrical machines Part 1: Rating and performanceIEC 60079 Part 20-1 Explosive gas atmosphere: Material characteristics for gas an
49、d vapour classification Test methods and dataNFPA 497 Flammable Liquids, Gases, or Vapors and of Hazardous (Classified) Locations for ElectricalInstallations in Chemical Process AreasUL 1004-1 Rotating Electrical Machines General RequirementsUL 674 Electric Motors and Generators for Use in Hazardous LocationsUL Subject 1836 Electric Motors and Generators for Use in Class I, Division 2, Class I, Zone 2, Class II,Division 2 and Zone 22 Hazardous (Classified) LocationsUL 60335-1 Safety of Household and Similar Electrical Appliances, Part 1: General RequirementsUL
