UL 998
Humidifiers

DETAILS
Edition Number:5SCC Approved:--
Edition Date:2011-04-25DOD Approved: --
Price Code:BANSI Approved: 2016-04-04
Type:ulcsa

  • SCOPE

    1 Scope

    1.1 These requirements cover humidifiers rated 600 V or less, and intended to be used in accordance with the National Electrical Code (NEC), ANSI/NFPA 70, and the Rules of the Canadian Electrical Code (CEC), Part I, C22.1 .

    1.2 These requirements cover humidifiers intended for residential and commercial use. This includes humidifiers of the centrifugal atomizing type, evaporative-media type, water-injection type, steam type, and the like. The humidifiers may be for installation in a room, mounted on a wall or a ceiling, or for duct or plenum mounting.

    1.3 These requirements apply to equipment that includes an electric heating element to heat air or water, or both.

    1.4 These requirements do not apply to evaporative coolers that are also intended to be used for cooling.

    1.5 These requirements do not apply to portable, electrode-type products, such as vaporizers, which are covered by the Standard for Electric Heating Appliances, UL 499, and the CSA Standard for Household Cooking and Liquid-Heating Appliances, CAN/CSA-C22.2 No. 64.

  • TABLE OF CONTENTS
    Expand All

    • Cover
    • Transmittal
    • UL Harmonized Standard Title Page
    • Table of Contents
      • HUMIDIFIERS
        • INTRODUCTION
          • 1 Scope
          • 2 Definitions
          • 3 General
            • 3.1 Components
            • 3.2 Reference publications
            • 3.3 Units of measurement
            • 3.4 Terminology
        • CONSTRUCTION
          • 4 General
          • 5 Enclosures
            • 5.1 General
            • 5.2 Nonmetallic materials
            • 5.3 Enclosure integrity
          • 6 Doors and Covers
          • 7 Accessibility of Uninsulated Hazardous Voltage Live Parts and Film-Coated Wire
          • 8 Protection Against Risk of Injury to Persons – Mechanical Protection
          • 9 Protection Against Risk of Injury to Persons – Materials
          • 10 Protection Against Risk of Injury to Persons – Switches, Controls, and Interlocks
          • 11 Protection Against Risk of Injury to Persons – Surface Temperatures
          • 12 Stability
          • 13 Strength of Handles
          • 14 Strength of Mounting
          • 15 Mechanical Assembly
          • 16 Liquid-Containing Parts
          • 17 Protection Against Corrosion
          • 18 Cord-Connected Products
          • 19 Permanently Connected Products
          • 20 Leads and Terminals
          • 21 Flexible Cords
          • 22 Strain Relief
          • 23 Bushings
          • 24 Current-Carrying Parts
          • 25 Internal Wiring
          • 26 Protection of Wiring
          • 27 Wiring Connections
          • 28 Electrical Insulation
          • 29 Separation of Circuits
          • 30 Secondary Circuits
            • 30.1 General
            • 30.2 Extra-low-voltage circuits
          • 31 Grounding
            • 31.1 General
            • 31.2 Permanently connected products
            • 31.3 Cord-connected products
            • 31.4 Bonding of internal parts
          • 32 Bonding Means
          • 33 Capacitors
          • 34 Coil Windings
          • 35 Heating Elements
          • 36 Motors
            • 36.1 General
            • 36.2 Motor overload protection
            • 36.3 Short circuit protection
          • 37 Overcurrent Protection
          • 38 Protection Against Overheating
          • 39 Receptacles
          • 40 Switches and Controllers
          • 41 Electrically Operated Valves and Solenoids
          • 42 Spacings
          • 43 Thermal Insulation
          • 44 Wetting Live Parts
          • 45 Internal Plumbing
          • 46 Filters
          • 47 Pressure Vessels and Parts Subjected to Pressure
          • 48 Protection of Service Personnel
            • 48.1 General
            • 48.2 Construction
          • 49 Duct- and Plenum-Mounted Products
          • 50 Construction of Duct- and Plenum-Mounted Products
            • 50.1 Installation
            • 50.2 Polymeric material
            • 50.3 Evaporation pad
            • 50.4 Supply cord
        • PERFORMANCE
          • 51 General Test Parameters
            • 51.1 General
            • 51.2 Voltage
            • 51.3 Ambient temperatures
          • 52 Leakage-Current Test
          • 53 Humidity-Conditioning Test
          • 54 Operation Test
          • 55 Starting Test
          • 56 Input Test
          • 57 Normal-Temperature Test
            • 57.1 All products
            • 57.2 Duct- or plenum-mounted products
          • 58 Disassembly and Reassembly Test
          • 59 Impact
          • 60 Rotating Members
          • 61 Dielectric Voltage-Withstand Test
          • 62 Strain-Relief Test
            • 62.1 General
            • 62.2 Through-cord switch
          • 63 Power-Supply Cord Push-Back Relief Test
          • 64 Cable-Clamp Test
          • 65 Abnormal Operation Test
            • 65.1 General
          • 66 Thermal Cutoff Test
          • 67 Gasket Test
          • 68 Liquid-Container Test
          • 69 Flooding of Live Parts Test
          • 70 Backflow Test
          • 71 Bonding-Conductor Test
          • 72 Tests on Parts Subject to Pressure
          • 73 Mold Stress-Relief Test
        • RATINGS
          • 74 Electrical Ratings
        • MARKING AND INSTRUCTIONS
          • 75 Identification and Ratings
          • 76 Informational and Instructional Markings
          • 77 Operating Instructions
          • 78 Field Wiring
        • TABLES AND FIGURES
          • TABLES
          • FIGURES
    • SMART ENABLED HUMIDIFIERS
    • Annex A Standards for components
    • Annex B French translations and markings
    • Annex C Manufacturing and Production Tests