UL 674
Electric Motors and Generators for Use in Hazardous (Classified) Locations

DETAILS
Edition Number:5SCC Approved:--
Edition Date:2011-05-31DOD Approved: 1987-11-06
Price Code:BANSI Approved: 2017-05-19
Type:ulcsance

  • SCOPE

    1 Scope

    1.1 This standard applies to electric motors and generators or submersible and nonsubmersible sewage pumps and systems suitable for use in Class I, Division 1, Groups B, C and D, and Class II, Division 1, Groups E, F and G, hazardous (classified) locations as defined by the Canadian Electrical Code, C22.1 Part I (CEC), the National Electrical Code, ANSI/NFPA 70 (NEC), and NOM-001–SEDE.

    1.2 This standard covers the same type of electrical equipment indicated in 1.1 for installation and use in Class I, Zone 1, Groups IIA and IIB, IIB+H2, and Zone 20 and 21 hazardous locations.

    1.3 This standard also covers other rotating machinery such as, but not limited to, electric brakes, tachometers, encoders, and slip rings.

    1.4 This standard does not address types of protection other than explosion-proof or dust-ignition-proof.

    1.5 For Canada Only - This standard does not include Canadian energy efficiency or product performance requirements. For such requirements, see Annex a, item 19. It is possible that item 19 is referenced in whole or in part in federal, provincial, territorial, or local laws or regulations relating to energy efficiency or product performance. The appropriate governmental authorities should be consulted to confirm whether item 19 has been referenced in laws or regulations.

    Note: This standard also does not include U.S. energy efficiency requirements for electric motors used in hazardous (classified) locations.

  • TABLE OF CONTENTS
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    • Cover
    • Transmittal
    • UL Harmonized Standard Title Page
    • Table of Contents
      • Body
        • 1 Scope
        • 2 Conditions for Use
        • 3 Normative References
        • 4 Dated and Undated References
        • 5 Definitions
        • 6 Components
        • 7 Units of Measurement
        • 8 Terminology
        • 9 Zone and Group Equivalency
          • 9.1 Class I, Zone 1, Group IIA
          • 9.2 Class I, Zone 1, Group IIB
          • 9.3 Class I, Zone 1, Group IIB+H2
          • 9.4 Zone 20 and 21
        • 10 Enclosures
          • 10.1 Material
          • 10.2 Porosity in castings
          • 10.3 Thickness
          • 10.4 Strength
        • 11 Joints in Enclosure
          • 11.1 General
          • 11.2 Groups C and D locations
          • 11.3 Group B locations
          • 11.4 Class II Locations
          • 11.5 Class I and II Locations - Main poles and interpoles of D.C. motors
        • 12 Holes in Enclosure
        • 13 Shaft Openings
          • 13.1 General
          • 13.2 Groups F and G locations
          • 13.3 Group E locations
        • 14 Drain and Breather Plugs in Enclosure
        • 15 Air-Gap Gauge Plugs in Enclosure
        • 16 Devices with Operating Rods or Spindles
        • 17 Protection Against Corrosion
          • 17.1 General
          • 17.2 Submersible sewage-pump motor
        • 18 Materials Applied to Joint Surfaces
        • 19 Field-Wiring Connections
          • 19.1 Permanently connected motors
          • 19.2 Field wiring leads
          • 19.3 Equipment grounding terminals and leads
        • 20 Cord-Connected Motors
          • 20.1 General
          • 20.2 Terminal enclosure
          • 20.3 Conductor seal
          • 20.4 Packing gland
          • 20.5 Strain relief
          • 20.6 Bonding for grounding
          • 20.7 Equipment grounding
          • 20.8 Attachment of threaded parts
        • 21 Assemblies of Equipment
          • 21.1 General
          • 21.2 Electric brake
        • 22 External Fans and Fan Guards
          • 22.1 Materials
          • 22.2 Fan-cooled motor
        • 23 Gasoline Submersible Motors
          • 23.1 General
          • 23.2 Lubrication
          • 23.3 Mechanical seal
        • 24 Leakage Detectors
          • 24.1 Submersible sewage-pump motor
          • 24.2 Cord-connected submersible sewage-pump motor
        • 25 Maximum External Surface Temperatures
        • 26 Devices for Limiting External Surfaces Temperatures
        • 27 Spacings
          • 27.1 Motors rated 1500 volts or less
          • 27.2 Motors rated more than 1500 volts
        • 28 Test Voltages and Test Conditions
        • 29 Instrumentation – Temperature Measurements
        • 30 Variable-Frequency Inverter-Drive Motors
        • 31 Temperature Tests – General
        • 32 Temperature Tests on Sinewave Power for Single Speed or Multi-Speed Motors
          • 32.1 Normal temperature test
          • 32.2 Running-overload test
          • 32.3 Running-overload to burnout test
          • 32.4 Single-phasing test
          • 32.5 Locked-rotor test
          • 32.6 72-Hour locked-rotor test
          • 32.7 Air test
          • 32.8 Dry-dust blanket test
          • 32.9 Moist-dust blanket test – Group G locations
        • 33 Temperature Tests for Variable-Frequency Inverter-Drive Motors
          • 33.1 Normal temperature test
          • 33.2 Running-overload test
          • 33.3 Running-overload to burnout test
          • 33.4 Locked-rotor test
          • 33.5 Air test
          • 33.6 Dry-dust blanket test
          • 33.7 Moist-dust blanket test – Group G locations
          • 33.8 Tests on fan-duty and air-over motors with temperature-limiting devices
        • 34 Dielectric-Voltage Withstand Test
        • 35 Dust-Penetration Test
        • 36 Explosion Test
          • 36.1 General
          • 36.2 Explosion pressure test
          • 36.3 Flame propagation test
          • 36.4 Exceptions for non-standard joints
        • 37 Over Pressure Test on Enclosures
        • 38 Tests on Temperature-Limiting Devices for Limiting External Surface Temperature
          • 38.1 Arc-rupturing tests for thermal cut-off device in D.C. motor circuit
          • 38.2 Temperature-limiting device in the motor-control circuit
          • 38.3 Overload test
          • 38.4 Endurance test
          • 38.5 Calibration test
        • 39 Secureness Test on Conduit Hubs
        • 40 Electrical-Resistance Test
        • 41 Accelerated-Aging Test on Bushings
        • 42 Cord-Pull Test
        • 43 Rough-Usage Test
        • 44 Drop Test
        • 45 Gasoline-Leakage Test
        • 46 Non-Metallic Fans and Fan Guards Test
          • 46.1 General
          • 46.2 Conductivity test
          • 46.3 Accumulation of static electricity test
        • 47 Pull Test on Tubes
        • 48 Sealing Compounds Test
        • 49 Low Ambient-Duty Motors
          • 49.1 General
          • 49.2 Construction
          • 49.3 Explosion test
          • 49.4 Drop test on lead seal
          • 49.5 Manufacturing and Production Tests – Dielectric Voltage-Withstand Test
        • 50 Grounding-Continuity Test
        • 51 Markings
    • Annex A (normative)Standard References
    • Annex B (informative)Standards for components
    • Annex C (normative)Construction for Waiver of Explosion Tests