UL 823
Standard for Electric Heaters For Use in Hazardous (Classified) Locations

DETAILS
Edition Number:9SCC Approved:--
Edition Date:2006-10-20DOD Approved: --
Price Code:BANSI Approved: 2016-04-22
Type:ulstd

  • SCOPE

    1 Scope

    1.1 These requirements cover explosion-proof, dust-ignition-proof and dust-tight portable and fixed electric heaters for installation and use in hazardous (classified) locations, Class I, Divisions 1 and 2, Groups A, B, C, and D; Class II, Division 1, Groups E, F, and G; Class II, Division 2, Groups F and G; and Class III, Divisions 1 and 2, in accordance with the National Electrical Code, NFPA 70.

    1.2 These requirements also cover explosion-proof electrical equipment for installation and use in Class I, Zone 1, Groups IIA, IIB and IIC hazardous (classified) locations and dust-ignition-proof equipment for use in Zone 20, 21, and 22 locations.


    1.2 revised effective December 30, 2010

    1.3 These requirements also cover explosion-proof electrical equipment that has been investigated for use in one or more specific gas or vapor atmospheres with or without additional Class I Groups. See 55.4.

    1.4 These requirements cover electric air heaters, electric hot-water or steam radiators, and electric hot plates rated 600 volts or less.

    1.5 These requirements also cover paint heaters, rated 600 volts or less, for use at pressures not exceeding 100 psig (690 kPa). Paint heaters operating at more than 100 psig may be investigated in accordance with these requirements and any additional requirements judged to be necessary.

    1.6 These requirements do not cover medical equipment.

    1.7 These requirements cover heaters for use only under the following atmospheric conditions:

    a)    A minimum ambient temperature of minus 50°C (minus 58°F);

    b)    An oxygen concentration not greater than 21 percent by volume; and

    c)    A nominal barometric pressure of one atmosphere.

  • TABLE OF CONTENTS
    Expand All

    • Cover
    • Transmittal
    • Table of Contents
      • Body
        • Part
          • INTRODUCTION
          • 1 Scope
          • 2 General
          • 3 Components
          • 4 Units of Measurement
          • 5 Undated References
          • 6 Enclosure Types
          • 7 Class I, Zone and Group Equivalency
            • 7.1 Class I, Zone 1, Group IIA
            • 7.2 Class I, Zone 1, Group IIB
            • 7.3 Class I, Zone 1, Group IIC
            • 7.4 Zone 20, Zone 21, and Zone 22
          • 8 Glossary
          • CONSTRUCTION – ALL HEATERS
          • 9 General
          • 10 Enclosure
            • 10.1 Enclosure
            • 10.2 Thickness
          • 11 Joints in Enclosures
            • 11.1 General
            • 11.2 Cemented joints
            • 11.3 Joints with flamepaths Class I, Groups A, B, C, and D
            • 11.4 Class I, Groups C and D locations
            • 11.5 Class I, Group B locations
            • 11.6 Class I, Group A locations
            • 11.7 Threaded joints
            • 11.8 Shaft Openings
            • 11.9 Class II
          • 12 Holes in Enclosures
            • 12.1 Class I locations
            • 12.2 Class II locations
          • 13 Hot-Water or Steam Radiators
            • 13.1 General
            • 13.2 Immersed heating elements
            • 13.3 Low-water cutoff
            • 13.4 Parts subject to pressure
            • 13.5 Water-fill opening
            • 13.6 Provisions for mounting
          • 14 Supply Connections – Fixed Heaters
            • 14.1 General
            • 14.2 Conduit seals
            • 14.3 Class II locations
            • 14.4 Supply connections – Portable heaters
            • 14.5 Cord clamp
            • 14.6 Securing of threaded joints
          • 15 Hooks and Handles
          • 16 Casters and Wheels
          • 17 External Metal Parts
          • 18 Bonding and Grounding
          • 19 Temperature-Limiting Devices
          • 20 Protection Against Corrosion
          • 21 Materials Applied to Joint Surfaces
          • PERFORMANCE
          • 22 Temperature Test
            • 22.1 General
            • 22.2 All heaters
            • 22.3 Heaters for Class I locations
            • 22.4 Heaters for Class II locations
            • 22.5 Heaters for simultaneous exposure to Class I and Class II locations
          • 23 Accelerated-Aging Test on Bushings
          • 24 Strain-Relief Test
          • 25 Rough-Usage Test
          • 26 Drop Test
          • 27 Overturning Test
          • 28 Stability Test
          • 29 Dielectric Voltage-Withstand Test
          • 30 Thermal-Cutoff Test
          • 31 Low-Water Cutoff Test
            • 31.1 General
            • 31.2 Overload
            • 31.3 Endurance
            • 31.4 Pressure
            • 31.5 Moist ammonia-air stress cracking test
          • 32 Non-Metallic Enclosure Materials Tests
            • 32.1 General
            • 32.2 Chemical compatibility by material samples
            • 32.3 Chemical compatibility by complete end product tests
            • 32.4 Test for accumulation of static electricity
            • 32.5 Tests on sealing compounds
          • 33 Explosion Tests
          • 34 Hydrostatic Pressure Test
          • 35 Dust Penetration Test
          • 36 Secureness of Conduit Hubs Test
          • 37 Resistance Test
            • 37.1 General
            • 37.2 Leakage test on factory-installed conduit seals
            • 37.3 Electrical-resistance test
            • 37.4 Equipment having coated threaded joint surfaces or conduit openings
            • 37.5 Tests on joint gaskets
        • PART II – HEATERS FOR CLASS I, DIVISION 2, GROUPS A, B, C, AND D LOCATIONS
          • GENERAL
          • 38 Details
          • CONSTRUCTION
          • 39 Enclosure
            • 39.1 General
            • 39.2 Enclosure material
          • 40 Supply Connections
          • 41 Protection Against Corrosion
          • 42 Arcing and Sparking Parts
          • PERFORMANCE
          • 43 Temperature Test
        • PART III – HEATERS FOR CLASS II, DIVISION 2, GROUP G LOCATIONS
          • GENERAL
          • 44 Details
          • 45 Enclosure
          • 46 Supply Connections
          • 47 Control Devices
          • 48 Protection Against Corrosion
          • PERFORMANCE
          • 49 Temperature Test
          • 50 Dust-Tight Enclosure Test
            • 50.1 General
            • 50.2 Dust-penetration method
            • 50.3 Dust-blast method
            • 50.4 Atomized-water method
        • Part
          • MANUFACTURING AND PRODUCTION TESTS
          • 51 General
          • 52 Air-Leakage Test
          • 53 Dielectric Voltage-Withstand Test
          • 54 Bonding Test
          • MARKINGS
          • 55 General
    • ALTERNATIVE EXPLOSION TESTS