1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULJULY 1, 20151UL 2874Outline of Investigation for Electric Motors for Use in Class I, Division 1Hazardous (Classified) Locations - Protection by Flammable AtmosphereMaintained above the UFLIssue N
2、umber: 1July 1, 2015Summary of TopicsThis first issue of the Outline of Investigation for Electric Motors for Usein Class I, Division 1 Hazardous (Classified) Locations - Protection byFlammable Atmosphere Maintained above the UFL, UL 2874, covers theexplosion protection of electric motors as permitt
3、ed by the nationalElectrical Code, NEC , Article 501.125 (A)(4) by means of submerging ina liquid that is flammable only when vaporized and mixed with air, or issubmerged in a gas or vapor at a pressure greater than atmospheric thatis flammable only when mixed with air.These requirements are for mac
4、hines that are for use only in industrialestablishments with restricted public access, where the conditions ofmaintenance and supervision ensure that only qualified persons servicethe installation.The machine is so arranged as to prevent energizing it until it has beenpurged with the liquid or gas t
5、o exclude air and also arranged toautomatically de-energize the equipment when the supply of liquid or gasor vapor fails or the pressure is reduced below atmospheric.ULs Outlines of Investigation are copyrighted by UL. Neither a printed norelectronic copy of an Outline of Investigation should be alt
6、ered in any way. All ofULs Outlines of Investigation and all copyrights, ownerships, and rights regardingthose Outlines of Investigation shall remain the sole and exclusive property of UL.COPYRIGHT 2015 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORD
7、ISTRIBUTION WITHOUT PERMISSION FROM ULJULY 1, 2015UL 28742No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTSINTRODUCTION1 Scope .42 Components 43 Units of Measurement .54 Undated References 5CONSTRUCTION5 General 56 M
8、otor Explosion Protection by Purging and Pressurization .67 Protection by Immersion 78 Controls and Instrumentation .7TESTING9 Over Pressure 810 Control .8MARKING AND INSTRUCTIONS11 General .812 Operating Manual 8BIBLIOGRAPHYJULY 1, 2015 UL 2874 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER RE
9、PRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULINTRODUCTION1 Scope1.1 These requirements cover electric motors for installation and use in Class I, Division 1 hazardous(Classified) locations, in accordance with the National Electrical Code, NFPA 70.1.2 These requirements cover motors of a type
10、designed to be continuously submerged in a liquid that isflammable only when vaporized and mixed with air, and which is for use only in industrial establishmentswith restricted public access, where the conditions of maintenance and supervision ensure that onlyqualified persons service the installati
11、on.1.3 These requirements cover motors of a type designed to operate within a gas or vapor that isflammable only when mixed with air at a pressure greater than atmospheric and which is for use only inindustrial establishments with restricted public access, where the conditions of maintenance andsupe
12、rvision ensure that only qualified persons service the installation.1.4 These requirements anticipate common flammable gases, gas mixtures or flammable liquids withsignificant margin between the upper flammable limit and the purged and pressurized state of use for themotor.1.5 These requirements als
13、o cover fused and unfused electrically tripped PV switches.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 featur
14、e or characteristic not required in the 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 incomp
15、lete in construction features or restricted 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.JULY 1, 2015UL 28744UL COPYRIGHTED MATERIAL N
16、OT AUTHORIZED FOR FURTHER REPRODUCTION 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 appeari
17、ng in the requirements of this outline shall beinterpreted as referring to the latest edition of that code or standard.CONSTRUCTION5 General5.1 The motor control means shall be so arranged as to prevent energizing the motor until it has beenpurged with the flammable liquid or flammable gas to exclud
18、e air as described in 6.1 7.1.5.2 The motor control means shall be so arranged to automatically de-energize the equipment when thesupply of liquid or gas or vapor fails or the pressure is reduced to a pre-set minimum pressure aboveatmospheric pressure. The minimum preset pressure shall be not less t
19、han 25 Pa (0.1 inches watercolumn).5.3 The equipment for monitoring 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
20、equipment shall be compatible with the fluid in which it is in contact.5.5 Materials of construction for pressurized casings shall comply with the requirements found in API 617.5.6 Electrical connections at the interface with the pressurized flammable gas containment shall complywith ISA 12.27.01.5.
21、7 The motor shall comply with the Standard for Rotating Electrical Machines General Requirements,UL 1004-1 and applicable subparts, or IEC 60034-1 and subparts, or the Standard for Electric Motors andGenerators for Use in Hazardous Locations, UL 674 or Outline of Investigation Electric Motors andGen
22、erators for Use in Class I, Division 2, Class I, Zone 2, Class II, Division 2 and Zone 22 Hazardous(Classified) Locations, UL 1836 as is appropriate.5.8 The installation and use shall comply with the National Electrical Code, NFPA 70.JULY 1, 2015 UL 2874 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR F
23、URTHER 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 motor until it has beenpurged with the gas to exclude air.6.2 The motor shall be permitted to be used
24、 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, followedby pressurization to not less than 25 Pa (0.1 inch water column).6.4 Displacing the air can be achie
25、ved 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 kpa in a closed system, followed by the introduction of the flammablegas; ord) By cyclical over pr
26、essurization and release of pressure of the flammable gas, to not lessthan 25 KPa, 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 motor shall be maintained at a positive pressure not less than 25 Paabove atmospheric pressure.6
27、.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 for assessment of functional safety systems.6.7 These requirements anticipate common flammable g
28、ases 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 significant safety margin when used at 90% orgreater gas mixtures. Conversely, hydrogen with a UFL of 7
29、5% 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 for the flammable material involved.6.8 LFL and UFL values are defined in IEC 60079-20-1 and in
30、NFPA 497 which also includes a table ofvalues.JULY 1, 2015UL 28746UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL7 Protection by Immersion7.1 The motor shall be permitted to be installed within a vessel, tank, or other containment means for t
31、heflammable fluid.7.2 The motor control means shall be so arranged as to prevent energizing the motor until it has beenpurged with the flammable fluid to exclude air.7.3 At startup, all air must be removed from the containment means before power is supplied to themotor. The motor control means shall
32、 be so arranged that the power is removed from the motor at apredetermined level above the motor to ensure that a flammable mixture can never be attained with powerapplied.7.4 Displacing the air can be achieved as follows:a) By continuous purging of not less than ten volumes of flammable liquid thro
33、ugh the motor;orb) By purging with an inert material such as nitrogen before introducing flammable liquid; orc) By evacuation to 0 kPa in a closed system, followed by the introduction of the flammableliquid; ord) By total immersion below the volume of flammable liquid contained within a vessel.7.5 F
34、ollowing the purging of air, the motor shall be maintained at a positive pressure above atmosphericor totally immersed beneath a predetermined level of flammable fluid. The vapor pressure of theflammable material shall be permitted to be the source of positive pressure when the conditions of useensu
35、re the absence of air under all conditions.7.6 A means shall be provided to continuously monitor the pressurization or immersion and removepower if pressure falls to within 25 Pa above atmospheric pressure or the immersion depth falls below apre-determined level, whichever means is applicable.8 Cont
36、rols and Instrumentation8.1 Control and instrumentation shall be verified to comply with the applicable requirements found in API617.8.2 Functional safety shall comply with the applicable requirements in the UL Category for Energy andIndustrial Systems Certified for Functional Safety, (FSPC).JULY 1,
37、 2015 UL 2874 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULTESTING9 Over Pressure9.1 Pressure containing parts shall be verified to comply with the applicable requirements found in API617.10 Control10.1 Control shall be verified to comply
38、with the applicable requirements found in API 617.MARKING AND INSTRUCTIONS11 General11.1 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, fr
39、equency, speed, number of phases, date code and temperature class.11.2 The motor compartment shall be marked as follows: WARNING FLAMMABLE GASPRESSURIZED MOTOR ENCLOSURE THIS ENCLOSURE MUST NOT BE OPENED UNTIL THEPRESSURE IS REDUCED TO ATMOSPHERIC PRESSURE, POWER HAS BEEN REMOVED AND THEFLAMMABLE PR
40、ESSURIZATION GAS HAS BEEN ISOLATED. DO NOT RESTORE POWER UNTILTHE PURGING AND PRESSURIZATION OPERATION IS COMPLETE. SEE OPERATING MANUAL NO._.11.3 Motors are permitted to be marked for use in Class I, Division 2, or Class I, Zone 1, or Class I, Zone2 in addition to or in place of Class I, Division 1
41、.12 Operating Manual12.1 A manual detailing the startup, control, use, and safe shutdown procedures shall be provided inaccordance with API 617.JULY 1, 2015UL 28748UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULBIBLIOGRAPHYThe standards liste
42、d 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 Flammable orCombu
43、stible Process FluidsAPI 617 (R2009) Axial and Centrifugal Compressors and Expander-compressors for Petroleum, Chemicaland Gas Industry ServicesNFPA 497 (2012) Flammable Liquids, Gases, or Vapors and of Hazardous (Classified) Locations forElectrical Installations in Chemical Process AreasIEC 60034-1
44、-2010 Rotating electrical machines Part 1: Rating and performanceIEC 60079 Part 20-1(2010) Explosive gas atmosphere: Material characteristics for gas and vapourclassification Test methods and dataUL 1004-1-2012 Rotating Electrical Machines General RequirementsUL 674 Ed 4 or Ed 5 Electric Motors and
45、Generators for Use in Hazardous LocationsUL Subject 1836 Ed 3 or Ed 4 Electric Motors and Generators for Use in Class I, Division 2, Class I, Zone2, Class II, Division 2 and Zone 22 Hazardous (Classified) LocationsJULY 1, 2015 UL 2874 BIB1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULJULY 1, 2015UL 2874BIB2No Text on This Page
