UL 268
Smoke Detectors for Fire Alarm Systems

DETAILS
Edition Number:7SCC Approved:--
Edition Date:2016-01-11DOD Approved: --
Price Code:CANSI Approved: 2016-07-15
Type:ululc

  • SCOPE

    1 Scope

    1.1 This Standard sets forth requirements for smoke detectors and accessories, including mechanical guards to be employed in ordinary indoor locations in accordance with the following:

    In the United States:

    a)     National Fire Alarm and Signaling Code, NFPA 72.

    In Canada:

    b)     Standard for the Installation of Fire Alarm Systems, CAN/ULC-S524;

    c)     National Building Code of Canada; and

    d)     National Fire Code of Canada.

    1.2 A smoke detector (e.g. ionization-type, photoelectric-type, smoke detector with supplementary heat detection type, combination smoke type, multi-criteria type) as covered by this Standard consists of an assembly of electrical components arranged to detect one or more products of combustion. At a minimum the detector shall contain a smoke (particulate) sensor. The products of combustion may consist of visible as well as invisible smoke particles, gases, heat, radiant energy, and water vapor.. The detector includes provision for the connection to a source of power, signaling, and optional remote control circuits. Additional functionality, such as a heat detector, heat sensor, or audible signaling appliance/device, is permitted to be incorporated as part of the smoke detector assembly.

    1.3 This standard covers the following types of detectors:

    a)    Detectors intended for open area protection and for connection to a compatible power supply or control unit for operation as part of a fire alarm system.

    b)    Detectors intended solely for control of releasing devices such as electromagnetic door holders, fire dampers or smoke dampers.

    c)    Detectors intended for both applications described in (a) and (b) above, and

    d)    In Canada, duct detectors.

    1.4 This standard does not cover the following:

    In the United States (a – g):

    a)    Control units to which the detectors are intended to be connected that are covered by the Standard for Control Units for Fire-Protective Signaling Systems, UL 864;

    b)    Self-contained single and multiple station smoke alarms, not intended for connection to a system control unit, that are covered by the Standard for Single and Multiple Station Smoke Alarms, UL 217;

    c)    A heat detector incorporated as a part of a smoke detector assembly, and covered by the Standard for Heat Detectors for Fire Protective Signaling Systems, UL 521; except for the requirements of the Fire Test (Heat Detector) and/or when part of a multi-criteria smoke detector;

    d)    A gas and vapor detector or sensor incorporated as a part of a smoke detector assembly, and covered by the Standard for Gas and Vapor Detectors and Sensors, UL 2075, except when part of a multi-criteria smoke detector;

    e)    Fire tests for smoke detectors integral with combination door closers and holders that are covered by the Standard for Door Closers-Holders, With or Without Integral Smoke Detectors, UL 228;

    f)    Commercial-residential detectors not intended for connection to a system control unit that are covered by the Standard for Smoke Detector Monitors and Accessories for Individual Living Units of Multifamily Residences and Hotel/Motel Rooms, UL 1730;

    g)    Detectors for monitoring the smoke density within flues or stacks;

    In Canada (h – m):

    h)    Control units that are covered by the Standard for Control Units for Fire Alarm Systems, ULC-S527;

    i)    Self-contained single and multiple station smoke alarms that are covered by the Standard For Smoke Alarms, CAN/ULC-S531;

    j)    A heat detector incorporated as a part of a smoke detector assembly, and covered by the Standard For Heat Actuated Fire Detectors for Fire Alarm Systems, CAN/ULC-S530 and/or when part of a multi-criteria smoke detector;

    k)    Fire tests for smoke detectors integral with combination door closers and holders that are covered by the Standard for Door Closers and Holders, ULC/ORD-C228;

    l)    Detectors for monitoring the smoke density within flues or stacks; and

    m)    A residential CO alarming device incorporated as a part of a smoke detector assembly, and covered by the CAN/CSA 6.19,  Standards for Residential CO Alarming Devices, except when part of a multi-criteria smoke detector.

    1.5 These requirements also cover all remote accessories that are intended to be connected to a smoke detector.

  • TABLE OF CONTENTS
    Expand All

    • Cover
    • Transmittal
    • UL Harmonized Standard Title Page
    • Table of Contents
      • Body
        • INTRODUCTION
          • 1 Scope
          • 2 General
            • 2.1 Assembly
            • 2.2 Components
            • 2.3 Units of measurement
            • 2.4 Reference publications
          • 3 Glossary
          • 4 Detector reliability prediction
          • 5 Installation and operating instructions
          • 6 Automatic drift compensation for smoke sensing
        • CONSTRUCTION
          • Assembly
          • 7 General
            • 7.1 Remote accessories
            • 7.2 Smoke sensitivity indicating means
            • 7.3 Radioactive materials
            • 7.4 Insect guards
            • 7.5 Supplementary heat sensor
            • 7.6 Maintenance (Field Cleaning)
          • 8 Compatibility information
            • 8.1 General
            • 8.2 Method of evaluation
            • 8.3 Changes affecting compatibility
          • 9 Servicing and maintenance protection
          • 10 Enclosure
            • 10.1 General
            • 10.2 Cast metal enclosures
            • 10.3 Sheet metal enclosures
            • 10.4 Nonmetallic enclosures
            • 10.5 Ventilating openings
            • 10.6 Covers
            • 10.7 Glass panels
          • 11 Corrosion protection
          • 12 Field wiring connections
            • 12.1 General
            • 12.2 Field wiring compartment
            • 12.3 Field wiring terminals (general)
            • 12.4 Special field-wiring terminals (qualified application)
            • 12.5 Field wiring leads
            • 12.6 Grounding terminals and leads
            • 12.7 Grounded supply terminals and leads
            • 12.8 Isolated (nongrounded) detectors
          • 13 Internal wiring
            • 13.1 General
            • 13.2 Wireways
            • 13.3 Splices
            • 13.4 Barriers
            • 13.5 Strain relief
          • 14 Bonding for grounding
          • Components
          • 15 General
            • 15.1 Mounting of components
            • 15.2 Operating components
            • 15.3 Current-carrying parts
          • 16 Bushings
          • 17 Electrical insulating material
          • 18 Lampholders and lamps
          • 19 Photocell illuminating lamps and light emitting diodes (LEDs) – Quality assurance program
            • 19.1 Light emitting diode (LED)
            • 19.2 Smoke detector manufacturer
          • 20 Motors
          • 21 Protective devices
          • 22 Printed wiring boards
          • 23 Switches
          • 24 Transformers and coils
          • 25 Dropping resistors
          • 26 Batteries
            • 26.1 General
            • 26.2 Battery connections
          • 27 Spacings
        • PERFORMANCE
          • 28 General
            • 28.1 Test units
            • 28.2 Accessories
            • 28.3 Performance of single sensor components of multi-criteria detectors
            • 28.4 Test voltages
            • 28.5 Test samples and data
            • 28.6 Component reliability data
            • 28.7 Smoke Detector guards
            • 28.8 Test conditions
            • 28.9 Tests and analysis
          • 29 Normal operation test
            • 29.1 General
            • 29.2 Standardized alarm signal
            • 29.3 Sensitivity shift criteria
          • 30 Electrical supervision test
            • 30.1 General
            • 30.2 Component Failure
            • 30.3 Photocell illuminating lamps and light emitting diodes (LEDs)
            • 30.4 Battery powered units
            • 30.5 Smoke Chamber monitoring (Required only when the detector employs a chamber monitoring feature)
            • 30.6 End-of-life signal
            • 30.7 Multi-criteria smoke detector with gas sensor
          • 31 Sensitivity test
            • 31.1 Sensitivity test – smoke sensor
            • 31.2 Sensitivity test – gas sensor of a multi-criteria detector
            • 31.3 Sensitivity test – heat sensor
            • 31.4 Sensitivity test - sensors other than smoke, gas or heat
          • 32 Automatic drift compensation for smoke sensing
          • 33 Directionality Test
          • 34 Velocity-sensitivity Test
            • 34.1 Smoke sensor
            • 34.2 Multi-criteria detector with gas sensor
          • 35 Smoke Entry (Stack Effect) Test
          • 36 Lamp Interchangeability Test (Photoelectric)
          • 37 Reduction in Light Output Test
          • 38 Stability Test
          • 39 Stability tests – multi-criteria detectors incorporating gas sensor(s)
          • 40 Test for effect of air velocity
          • 41 Fire tests
            • 41.1 General
            • 41.2 Paper fire
            • 41.3 Wood fire (United States only)
            • 41.4 Flammable liquid fire (Canada only)
            • 41.5 Igniter assembly (Canada only)
            • 41.6 Test method
          • 42 Smoldering smoke test
          • 43 Smoldering smoke test – maximum obscuration without alarm (United States only)
          • 44 Selectivity Test – Multi-criteria Detectors Incorporating Gas Sensor(s)
          • 45 Circuit Measurement Test
            • 45.1 General
            • 45.2 Battery trouble voltage determination
          • 46 Overvoltage and Undervoltage Tests
            • 46.1 Overvoltage test
            • 46.2 Undervoltage test
            • 46.3 Two-wire smoke detectors
          • 47 Temperature Test
          • 48 Vibration Test
          • 49 Replacement Test, Head and Covers
          • 50 Jarring test
          • 51 Variable Ambient Temperature Tests
            • 51.1 Operation in high and low ambients
            • 51.2 Effect of shipping and storage – Single and Multi-criteria Detectors
            • 51.3 Effect of shipping and storage – Multicriteria Detectors Incorporating Gas Sensor(s)
          • 52 Humidity Test
            • 52.1 High humidity
            • 52.2 Low humidity (multi-criteria detectors with gas sensors
          • 53 Corrosion Tests
          • 54 Alternate Corrosion Test for Detectors with a Specified Life Not Exceeding 10 Years (21 day)
          • 55 Transient Tests
            • 55.1 General
            • 55.2 Internally induced transients
            • 55.3 Extraneous transients
            • 55.4 Supply line (ring wave surge voltage) transients
            • 55.5 Supply line (extra-low-voltage circuit) transients
          • 56 Static Discharge Test
          • 57 Dust Test
          • 58 Overload Tests
            • 58.1 Detector
            • 58.2 Separately energized circuits
          • 59 Endurance Test
          • 60 Audible signaling appliance
          • 61 Fire Test – Smoke Detector with supplementary heat detection
          • 62 Abnormal Operation Test
          • 63 Locked Rotor Test
            • 63.1 Motors
            • 63.2 Thermal or overcurrent protection (United States only)
            • 63.3 Impedance protection (United States only)
          • 64 Dielectric Voltage-Withstand Test
          • 65 Polarity Reversal Test
          • 66 Tests on Polymeric Materials
            • 66.1 General
            • 66.2 Temperature test
            • 66.3 Flame test – 19 mm (3/4-inch)
            • 66.4 Flame test – 127 mm (5-inch)
          • 67 Strain Relief Test
            • 67.1 General
            • 67.2 Special field-wiring terminals
          • 68 Non-compulsory Fire and Smoldering Smoke Tests (United States Only)
          • 69 Survivability Test
          • 70 Audibility test
            • 70.1 General
            • 70.2 Sound output measurement (United States only)
            • 70.3 Sound output measurement (Canada only)
            • 70.4 Low frequency alarm signal format
          • 71 Field Service Tests
            • 71.1 Go/no-go field test (for the smoke sensor)
            • 71.2 Go/No-Go field test (gas sensors used in multi-criteria smoke detectors)
            • 71.3 Maintenance (Cleaning)
          • 72 Battery Tests
          • 73 Conformal Coatings on Printed Wiring Boards
            • 73.1 General
            • 73.2 Low voltage printed wiring boards
            • 73.3 High voltage printed wiring boards
          • 74 Air duct detectors (Canada Only)
        • MANUFACTURING AND PRODUCTION
          • 75 General
          • 76 Sensitivity calibration tests
          • 77 Smoke tests
          • 78 Photocell illuminating lamp test
          • 79 Production line dielectric voltage-withstand tests
          • 80 Measurement of in-service reliability for multi-criteria detectors with gas sensor(s)
            • 80.1 Required in-service reliability
            • 80.2 Sample frequency and sample size
            • 80.3 Test results and record keeping
        • MARKING
          • 81 General
          • 82 Packaging marking (United States Only)
        • INSTRUCTIONS
          • 83 Installation instructions – wiring diagram
            • 83.1 All detectors
            • 83.2 Four-wire detectors
            • 83.3 Two-wire detectors
            • 83.4 Installation Instructions and User Manual – RF Equipment
          • 84 Technical bulletin
        • Section
          • TABLES Tables
        • Section
          • FIGURES Figures
    • ANNEX A (INFORMATIVE) – TYPICAL CANADIAN SENSITIVITY SMOKE TEST CHAMBER CONSTRUCTION
    • ANNEX B (INFORMATIVE) – TYPICAL UNITED STATES SENSITIVITY SMOKE TEST CHAMBER CONSTRUCTION
    • ANNEX C (NORMATIVE) – OBSCURATION CALCULATIONS
    • ANNEX D (NORMATIVE) – RELIABILITY PREDICTION AND CRITERIA FOR ACCEPTANCE
    • ANNEX E (INFORMATIVE) – STANDARDS FOR COMPONENTS
    • ANNEX F (INFORMATIVE) – TYPICAL AIR DUCT DETECTOR TEST FACILITY (CANADA ONLY)
    • ANNEX G (NORMATIVE) – FRENCH TRANSLATIONS OF REQUIRED MARKINGS
    • ANNEX H (INFORMATIVE) – SAMPLE SIZE DETERMINATION FOR IN SERVICE RELIABILITY TESTING OF MULTICRITERIA DETECTORS CONSISTING OF GAS DETECTION
    • ANNEX I (NORMATIVE) – FLAMING AND SMOLDERING POLYURETHANE FOAM TESTS AND COOKING NUISANCE TEST REQUIREMENTS (UNITED STATES ONLY)