UL 1437
Standard for Electrical Analog Instruments - Panel Board Types

DETAILS
Edition Number:4SCC Approved:--
Edition Date:2006-12-12DOD Approved: 1994-10-03
Price Code:AANSI Approved: --
Type:ulstd

  • SCOPE

    1 Scope

    1.1 These requirements cover electrical and electrically operated indicating and recording instruments of the analog type that are powered only from the measured parameter and are intended for ordinary use in panel boards and the like.

    1.2 These requirements cover direct-acting or indirect-acting instruments and accessories that may contain electronic devices.

    1.3 These requirements cover instruments indicating quantities of electrical analogs including all of the following:

    a)    Ammeters.

    b)    Voltmeters.

    c)    Wattmeters.

    d)    Varmeters (reactive volt-ampere meters).

    e)    Frequency meters.

    f)    Power-factor meters.

    g)    Synchroscopes.

    1.4 These requirements cover instruments constructed for special purposes such as, ultrasensitive d-c microammeters, high-resistance voltmeters, thermo-milliammeters, thermal voltmeters of the vacuum-couple type, and instruments with special and unusual ranges.

    1.5 These requirements cover analog instruments that may be categorized according to use or principle of operation as follows:

    a)    Use:

    1)    Panel Type, including edgewise.

    2)    Switchboard type, including edgewise.

    b)    Principle of operation:

    1)    Electrodynamics.

    2)    Permanent-magnet moving coil.

    3)    Moving iron.

    4)    Thermocouple.

    5)    Rectifier.

    1.6 These requirements also cover auxiliary equipment and accessories designed to be used with measuring instruments as indicated in 1.1 – 1.5.

    1.7 These requirements do not cover:

    a)    Indicating instruments provided with arrangements for curve drawing, contact making, and the like that derive the power for the functioning of these arrangements from an external source other than the measured parameter.

    b)    Instruments that use active devices such as transistors, electron tubes, and the like for amplifying the electrical quantity measured, that require a power source other than the quantity measured for operation. An example of this is a battery-powered ohmmeter. This equipment is covered by the requirements for electrical and electronic measuring and testing equipment, UL 1244.

    1.8 Instruments covered by these requirements are intended for use indoors or in sheltered (from the elements) locations, as follows:

    a)    Temperature – 5 – 40°C or 41 – 104°F; instruments may occasionally be used for temporary or short periods at minus 10 – plus 5°C or 14 – 41°F.

    b)    Altitude – Up to 2200 meters (7218 feet).

    c)    Relative Humidity – Up to 80 percent.

    1.9 These requirements do not cover certain other properties of the instruments such as effectiveness, accuracy, or reliability.

    1.10 Throughout this Standard the term "instrument" applies to analog indicating and recording instruments and their accessories as described in 1.1 – 1.6.

    1.11 A product that contains features, characteristics, components, materials, or systems new or different from those covered by the requirements in this Standard, and that involves a risk of fire, electric shock, or injury to persons shall be evaluated using the appropriate additional component and end-product requirements as determined necessary to maintain the acceptable level of safety as originally anticipated by the intent of this Standard. A product whose features, characteristics, components, materials, or systems conflict with specific requirements or provisions of this Standard cannot be judged to comply with this Standard. Where considered appropriate, revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this Standard.

  • TABLE OF CONTENTS
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    • Cover
    • Transmittal
    • Table of Contents
      • Body
        • INTRODUCTION
          • 1 Scope
          • 2 Glossary
          • 3 Components
          • 4 Units of Measurement
          • 5 References
        • CONSTRUCTION
          • 6 General
            • 6.1 General
            • 6.2 Component construction requirements
          • 7 Enclosure and Insulating Materials
            • 7.1 General
            • 7.2 Enclosure materials
            • 7.3 Insulating materials
          • 8 Accessibility of Live Parts
            • 8.1 General
            • 8.2 Determination of accessibility
            • 8.3 Determination of electric shock
            • 8.4 Instrument connection
            • 8.5 Operator servicing
            • 8.6 Operating shafts
            • 8.7 Adjustment openings
          • 9 Connection Devices
            • 9.1 Terminals
            • 9.2 Insulation
            • 9.3 Protective ground terminals
            • 9.4 Screw connections
          • 10 Internal Wiring
          • 11 Separation of Circuits
            • 11.1 General
            • 11.2 Printed-wiring boards
          • 12 Spacings
            • 12.1 Circuits
            • 12.2 Fasteners
          • 13 Grounding
          • 14 Component Parts and Accessories
            • 14.1 Resistors and inductors
            • 14.2 Component short-circuit
            • 14.3 Overcurrent protective and thermal-limiting devices
            • 14.4 Accessories
          • 15 Subdivision of Circuits Into Groups
            • 15.1 General
            • 15.2 Open-circuit voltage measurement
            • 15.3 Available-current measurement
            • 15.4 Current-limiting means
            • 15.5 Overload-protector rating
            • 15.6 Fixed-impedance rating
            • 15.7 Regulating-network rating
        • PERFORMANCE
          • 16 General
            • 16.1 General
            • 16.2 Voltmeter sensitivity
            • 16.3 Cheesecloth indicators
            • 16.4 Reference test conditions (reference conditions for test purposes)
            • 16.5 Protective devices
            • 16.6 Voltage and current
          • 17 Leakage Current Test
            • 17.1 General
            • 17.2 Specified measuring instrument
            • 17.3 Instrument connection
            • 17.4 Enclosure of insulating material
          • 18 Normal Temperature Test
            • 18.1 General
            • 18.2 Instrument mounting
            • 18.3 Instrument connections
            • 18.4 Doors and covers
            • 18.5 Thermocouples
            • 18.6 Temperature limits
          • 19 High-Ambient Temperature Evaluation
            • 19.1 Instrument conditioning
            • 19.2 Insulating materials
            • 19.3 Polymeric enclosures
          • 20 Insulation Voltage Test (Dielectric Voltage-Withstand Test)
            • 20.1 General
            • 20.2 Indication of breakdown
          • 21 Humidity Conditioning
            • 21.1 General
            • 21.2 Preconditioning
            • 21.3 Conditioning
          • 22 Torque Test for Terminals
            • 22.1 General
            • 22.2 Direction and application of torque
          • 23 Testing Under Fault Conditions
            • 23.1 General
            • 23.2 Fire
            • 23.3 Electric shock
            • 23.4 Protective devices and circuit components
            • 23.5 Fault conditions
            • 23.6 Multi-function and over-range test
          • 24 Polymeric Enclosure – Stress-Relief Distortion
            • 24.1 General
            • 24.2 Test criteria
            • 24.3 Test procedure
          • 25 Enclosure Impact Test (Does Not Apply to Windows)
            • 25.1 General
            • 25.2 Test procedure
            • 25.3 Alternate enclosure impact test
          • 26 Window Impact
            • 26.1 General
          • 27 Polymeric-Enclosure Pressure
            • 27.1 General
            • 27.2 Test procedure
          • 28 Window Pressure
            • 28.1 General
            • 28.2 Test method
        • MANUFACTURING AND PRODUCTION TESTS
          • 29 General
            • 29.1 General
            • 29.2 Test equipment
        • MARKINGS
          • 30 Details
            • 30.1 General requirements
            • 30.2 Manufacturer's identification
            • 30.3 Model identification
            • 30.4 Factory identification
            • 30.5 Voltage measuring or testing terminal rating
            • 30.6 Current measuring terminal rating
            • 30.7 Isolated measuring terminal rating
            • 30.8 Polarity
            • 30.9 Edgewise instruments
            • 30.10 Radio-frequency instruments
            • 30.11 Scale marking
            • 30.12 External accessories
          • 31 Caution and Warning Notices
            • 31.1 Protective ground terminals
            • 31.2 Markings requiring explanations
            • 31.3 Fuse-replacement caution markings
            • 31.4 Protective-device-replacement caution marking