UL 1008
Transfer Switch Equipment

DETAILS
Edition Number:8SCC Approved:--
Edition Date:2014-12-22DOD Approved: --
Price Code:DANSI Approved: 2015-10-15
Type:ulcsance

  • SCOPE

    1 Scope

    1.1 This standard applies to:

    a)    Automatic transfer switches;

    b)    Manual or non-automatic transfer switches;

    c)    Closed transition transfer switches;

    d)    Hybrid transfer switches;

    e)    Transfer switches for fire pumps;

    f)    Bypass/isolating switches;

    g)    Softload transfer switches;

    h)    Transfer switches intended for use as service equipment; and

    i)    In Mexico and the United States, branch circuit emergency lighting transfer switches (BCELTS). In Canada, this requirement does not apply.

    that have a maximum rating of 1000 volts for use in non-hazardous locations, in accordance with Annex a1, Item 1.

    1.2 This standard specifically does not apply to:

    a)    Double-throw switches for use in optional standby systems;

    b)    Switches used in equipment manufactured in accordance with Annex a1, Item 9;

    c)    In Canada, manually operated generator transfer panels in accordance with Annex a1, Item 12.

    d)    Transfer switches rated over 1000 V; and

    e)    Solid-state (static) transfer equipment.

    1.3 These requirements apply to transfer switches and their associated control devices including voltage sensing relays, frequency sensing relays, time-delay relays, and the like.

    1.4 These requirements apply to completely enclosed transfer switches and to open types intended for mounting in other equipment such as switchboards.

    1.5 These requirements apply to bypass/isolation switches used to manually select an available power source to feed load circuits and to provide for total isolation of an automatic transfer switch. These switches may be completely enclosed, enclosed with the transfer switch, or of the open type intended for mounting in other equipment. Refer to Annex d.

    1.6 In Canada, automatic transfer switches built to the optional standby requirements of this standard are not permitted. In Mexico and the United States, this requirement does not apply.

    1.7 These requirements cover enclosed inlets intended to facilitate connection of portable generators to transfer equipment.

  • TABLE OF CONTENTS
    Expand All

    • Cover
    • Transmittal
    • UL Harmonized Standard Title Page
    • Table of Contents
      • TRANSFER SWITCH EQUIPMENT
        • 1 Scope
        • 2 General Requirements
          • 2.1 General
          • 2.2 Kits, other than field-wiring kits
          • 2.3 Reference publications
          • 2.4 Units of measurement
        • 3 Definitions
        • 4 Characteristics
          • 4.1 Summary of characteristics
          • 4.2 Ratings
        • 5 Product Information
          • 5.1 Data requirements
          • 5.2 Marking requirements
          • 5.3 Instructions for installation, operation, and maintenance
        • 6 Construction Requirements
          • 6.1 Materials
          • 6.2 Intended for service equipment
          • 6.3 Clearance and creepage distances
          • 6.4 Components
          • 6.5 Enclosures
          • 6.6 Connections for wiring systems
          • 6.7 Corrosion protection
          • 6.8 Insulating materials
          • 6.9 Bases
          • 6.10 Mounting of parts
          • 6.11 Guarding and accessibility of live parts
          • 6.12 Current-carrying parts
          • 6.13 Field-wiring terminals
          • 6.14 Internal wiring
          • 6.15 Grounding and bonding
          • 6.16 Ground-fault protection
          • 6.17 Receptacles
          • 6.18 Wiring spaces
          • 6.19 Transfer switches with integral inlets for portable generator connection
          • 6.20 Inlets for generator connection
        • 7 Performance Requirements
          • 7.1 Operating mechanism
          • 7.2 Temperature rise
          • 7.3 Dielectric properties
          • 7.4 Ability to make and break under no-load, normal load, and overload conditions
          • 7.5 Short-circuit tests
        • 8 Service Equipment Requirements
          • 8.1 Service equipment for use in Mexico and the United States
          • 8.2 Service equipment for use in Canada
        • 9 Test Requirements – General
          • 9.1 General
          • 9.2 Performance
          • 9.3 Overvoltage condition
          • 9.4 Undervoltage condition
          • 9.5 Operation on loss of supply voltage
          • 9.6 Operation on reduction of supply voltage
          • 9.7 Transfer on availability of alternative voltage or voltage-frequency
          • 9.8 Temperature rise test
          • 9.9 Dielectric voltage-withstand test
          • 9.10 Overload test
          • 9.11 Contact opening test
          • 9.12 Endurance test
          • 9.13 Short-circuit test
          • 9.14 Dielectric voltage-withstand test (following short-circuit withstand or closing tests)
          • 9.15 Short-time current rating test – optional
          • 9.16 Receptacle withstand test
          • 9.17 Strength of insulating base and support tests
        • 10 Test Requirements – Routine Tests
          • 10.1 Ground-fault protection
        • TABLES Tables
    • Annex A1Normative references
    • Annex A2Informative references
    • Annex B (informative)French translation of markings
    • Annex C (informative)Spanish translation of markings
    • Annex D (normative) Bypass/Isolation switches
    • Annex E (normative) Transfer switches for fire pump service
    • Annex F (Normative in Canada) (Informative in Mexico and the United States)Hybrid Transfer Switches
    • Annex G (normative) Softload Transfer Switches
    • Annex H (Normative in Mexico and the United States) (Informative in Canada)Instrumentation and Calibration of High Capacity Circuits
    • Annex I (informative) Sample Markings
    • Annex J (normative) Inlet Assemblies for Transfer Switch Equipment