UL 20
General-Use Snap Switches

DETAILS
Edition Number:14SCC Approved:--
Edition Date:2018-07-20DOD Approved: 1981-12-04
Price Code:BANSI Approved: 2018-07-20
Type:ulcsance

  • SCOPE

    1 Scope

    1.1 The requirements of this Standard apply to manually operated, general-use snap switches for connection to copper (Cu) or copper-clad conductors used in accordance with the National Electrical Code (NEC), ANSI/NFPA 70, or the Canadian Electrical Code (CE Code), Part I, and and intended to be permanently connected in accordance with the NEC and the CE Code, Part I. In Canada, requirements for switches for connection to aluminum (Al) conductors used in accordance with the CE Code, Part I, and intended for connection to wiring systems recognized by the CE Code, Part I, are covered in Annex b.

    1.2 This Standard applies to ac/dc rated switches for which the load ratings do not exceed 60 A at 250 V or less, 30 A at 251 V – 600 V, and 2 hp at 125 V – 600 V or less. This Standard also covers ac-only rated switches for which the load ratings do not exceed 30 A at 347 VAC or less.

    1.3 This Standard applies to switches constructed to be installed readily in a flush device box or on an outlet-box cover and intended for connection to branch-circuit wiring.

    1.4 This Standard applies to pendant and through-cord switches intended for field installation on flexible cord and provided with one "on" and one "off" position.

    1.5 This Standard applies to switches intended for surface mounting and provided with a separable base and cover for connection to exposed wiring consisting of nonmetallic sheathed cable or open wiring on insulators (knob and tube).

    1.6 This Standard applies to self-contained switches intended for flush mounting without a separate outlet box and for connection to branch-circuit wiring consisting of one or more non-metallic sheathed cables containing copper conductors.

    1.7 This Standard applies to ac/dc fixture switches intended to be installed in fixtures to control incandescent lighting or fans for connection to branch-circuit wiring.

    1.8 This Standard also applies to single-pole, momentary-contact door switches constructed to be installed readily in a special-purpose device box or on an outlet-box cover for connection to branch-circuit wiring.

    1.9 This Standard does not apply to:

    a) Clock operated switches specified in the Standard for Clock-Operated Switches, UL 917, and CSA Standard C22.2 No. 177;

    b) Dimmer switches specified in the Standard for Solid-State Dimming Controls, UL 1472, and CSA Standard C22.2 No. 184.1;

    c) Industrial control equipment specified in the Standard for Industrial Control Equipment, UL 508, and CSA Standard C22.2 No. 14;

    d) Solid-state, single-phase motor speed controls specified in the Standard for Solid-State Fan Speed Controls, UL 1917, and CSA Standard C22.2 No. 156;

    e) Special-use and ac-only fixture switches specified in the Standard for Switches for Appliances – Part 1: General Requirements, UL 61058-1, and CSA Standard C22.2 No. 55; and

    f) Switches for use in hazardous locations specified in the Standard for Explosion-Proof and Dust-Ignition-Proof Electrical Equipment for Use in Hazardous (Classified) Locations, UL 1203, and CSA Standard C22.2 No. 159.

    1.10 For switches intended for connection to branch-circuit wiring containing aluminum conductors, refer to the Standard for Receptacles and Switches Intended for Use with Aluminum Wire, UL 1567, or to Annex b.

    In Mexico, this Clause is not applicable. The use of aluminum conductors from 0.824 mm2 (18 AWG) to 8.37 mm2 (8 AWG) is prohibited.

  • TABLE OF CONTENTS
    Expand All

    • Cover
    • Transmittal
    • UL Harmonized Standard Title Page
    • Table of Contents
      • Body
        • 1 Scope
        • 2 Definitions
        • 3 General
          • 3.1 Components
          • 3.2 Units of Measurement
          • 3.3 Reference Publications
        • 4 Construction
          • 4.1 Enclosure
          • 4.2 Lining
          • 4.3 Bushings and Strain Relief
          • 4.4 Bases and Bodies
          • 4.5 Current-Carrying Parts
          • 4.6 Separable Jumper Connector for Separable Terminals
          • 4.7 Separable Terminal Assembly
          • 4.8 Insulating Material
          • 4.9 Actuating Members
          • 4.10 Creepage Distances, Clearances, and Distances Through Sealing Compounds
          • 4.11 Assembly
          • 4.12 Provision for Grounding
        • 5 Testing
          • 5.1 General
          • 5.2 Test Sequence
          • 5.3 Tungsten-Filament-Lamp Load Characteristics
          • 5.4 Assembly Test
          • 5.5 Test Conditions
          • 5.6 Overload Test
          • 5.7 Endurance Test
          • 5.8 Temperature Test
          • 5.9 Dielectric Voltage-Withstand Test
          • 5.10 Security of Switch Leads Test
          • 5.11 Push-In Terminal Tests
          • 5.12 Effect of Heat on Actuating Members Test
          • 5.13 Switching Mechanism Test
          • 5.14 Strain-Relief Test
          • 5.15 Fault Current Test
          • 5.16 Crushing Test
          • 5.17 Resistance to Heat Test
          • 5.18 Door Switch Assembly Test
          • 5.19 Retention of Tab Connection Test
          • 5.20 Separable Connector Pull Test
          • 5.21 Mold Stress Relief Test
          • 5.22 Separable Terminal Assembly Humidity Conditioning Followed By Dielectric Test
          • 5.23 Short Circuit Withstand Test
          • 5.24 Latching Mechanism Test
          • 5.25 Abnormal Overload Test
          • 5.26 Temperature Test
          • 5.27 Continuity Impedance Test
          • 5.28 Bonding (Fault Current) Test
          • 5.29 Mounting Yoke Resistance Test
          • 5.30 Combination Wire Binding/Pressure-Type Terminal Assembly Test
          • 5.31 Inrush Current
        • 6 Ratings
        • 7 Markings
          • 7.1 General
          • 7.2 Supplementary Markings
          • 7.3 Location
          • 7.4 Tungsten
          • 7.5 AC-Only Identification
          • 7.6 Switch Termination Restrictions
          • 7.7 For Use with Electronic Ballasts
        • 8 Self-Contained Switches for Use Without a Separate Outlet Box
          • 8.1 General
          • 8.2 Construction
          • 8.3 Performance Testing
          • 8.4 Markings and Instructions
    • AC ONLY FLUSH SWITCH WITH INTEGRAL POWER SUPPLY WITH CLASS 2 OUTPUT CONNECTORS
    • ANNEX A (Normative) Standards for Components
    • Annex B (Informative) Canadian Requirements for CO/ALR Switches