UL 1561
Standard for Dry-Type General Purpose and Power Transformers

DETAILS
Edition Number:4SCC Approved:--
Edition Date:2011-03-02DOD Approved: --
Price Code:CANSI Approved: 2015-06-16
Type:ulstd

  • SCOPE

    1 Scope

    1.1 These requirements cover:

    a)    General purpose and power transformers of the air-cooled, dry, ventilated, and nonventilated types to be used in accordance with the National Electrical Code, ANSI/NFPA 70. Constructions include step up, step down, insulating, and autotransformer type transformers as well as air-cooled and dry-type reactors or

    b)    General purpose and power transformers of the exposed core, air-cooled, dry, and compound-filled types rated more than 10 kVA to be used in accordance with the National Electrical Code, ANSI/NFPA 70. Constructions include step up, step down, insulating, and autotransformer type transformers as well as air-cooled, dry, and compound-filled type reactors.

    1.2 These requirements do not cover ballasts for high intensity discharge (HID) lamps (metal halide, mercury vapor, and sodium types) or fluorescent lamps, exposed core transformers, compound-filled transformers, liquid-filled transformers, voltage regulators, general use or special types of transformers covered in requirements for other electrical equipment, autotransformers forming part of industrial control equipment, motor-starting autotransformers, variable voltage autotransformers, transformers having a nominal primary or secondary rating of more than 600 volts, or overvoltage taps rated greater than 660 volts.

    1.3 These requirements do not cover transformers provided with waveshaping or rectifying circuitry. Waveshaping or rectifying circuits may include components such as diodes and transistors. Components such as capacitors, transient voltage surge suppressors, and surge arresters are not considered to be waveshaping or rectifying devices.

  • TABLE OF CONTENTS
    Expand All

    • Cover
    • Transmittal
    • Table of Contents
      • Body
        • INTRODUCTION
          • 1 Scope
          • 2 Components
          • 3 Units of Measurement
          • 4 Undated References
          • 5 Glossary
        • CONSTRUCTION
          • 6 Mechanical Assembly
          • 7 Enclosure
            • 7.1 General
            • 7.2 Sheet metal
            • 7.3 Nonmetallic enclosures
            • 7.4 Mounting
            • 7.5 Covers
            • 7.6 Ventilation
            • 7.7 Specific environmental conditions
            • 7.8 Corrosion protection
          • 8 Corrosion Resistance
          • 9 Supply and Load Connections
          • 10 Field Wiring Connections
            • 10.1 General
            • 10.2 Leads
            • 10.3 Pressure terminal connectors
          • 11 Current-Carrying Parts
          • 12 Electrical Insulation
          • 13 Internal Wiring
          • 14 Coil Insulation
          • 15 Coil Details
          • 16 Electrical Spacings
          • 17 Insulating Barriers
          • 18 Transient Voltage Surge Suppressors
          • 19 Capacitors
          • 20 Surge Arresters
        • PERFORMANCE
          • 21 General
          • 22 Impedance Test
          • 23 Temperature Test
            • 23.1 General
            • 23.2 Units for wall mounting
            • 23.3 Units for floor mounting
            • 23.4 Clamped bus joint
          • 24 Dielectric Voltage-Withstand Test
            • 24.1 Applied potential
            • 24.2 Induced potential
          • 25 Overload Test
          • 26 Dielectric Voltage-Withstand Test Repeated
          • 27 Lifting or Mounting Means Test
          • 28 Enclosure Strength Tests
            • 28.1 Deflection test
            • 28.2 Compression test
          • 29 Clamped Insulating Joint and Insulating Barrier Tests
          • 30 Water Spray Test
          • 31 Drip Test
          • 32 Icing Test
          • 33 Rust Resistance Test
          • 34 Corrosion Resistance Test
          • 35 Metallic Coating Thickness Test
          • 36 Production-Line Dielectric Voltage-Withstand Test
        • RATINGS
          • 37 General
        • MARKINGS
          • 38 Details
            • 38.1 General
            • 38.2 Nonsinusoidal load ratings
            • 38.3 Insulation temperature class
            • 38.4 Temperature rise
            • 38.5 Temperature sensor
            • 38.6 Ambient temperature
            • 38.7 Autotransformer, elevated voltage (buck or boost)
            • 38.8 Impedance
            • 38.9 Environmental condition enclosures
            • 38.10 Mounting
            • 38.11 Weight
            • 38.12 Field wiring
          • 39 Permanence of Marking
    • APPENDIX A