UL 347A
Standard for Medium Voltage Power Conversion Equipment

DETAILS
Edition Number:1SCC Approved:--
Edition Date:2015-09-08DOD Approved: --
Price Code:AANSI Approved: 2019-02-19
Type:ulstd

  • SCOPE

    1 Scope

    1.1 These requirements cover enclosed medium voltage power conversion equipment, such as variable frequency controllers, that control and transfer power to motors. These requirements also cover power-supply modules, input/output modules, and electronic assemblies, for use in or with power conversion equipment.

    1.2 These requirements cover equipment rated above 1500 volts to 38kV. The equipment may have input ratings greater than 1500 V, output ratings greater than 1500 V, or both.

    1.3 These requirements do not cover equipment for use in hazardous locations as defined by the National Electrical Code, NFPA 70.

    1.4 These requirements do not cover solid state reduced voltage motor controllers (soft starters). This type of equipment is covered by the Standard for Medium Voltage AC Contactors, Controllers, and Control Centers, UL 347.

    1.5 These requirements do not cover low voltage power conversion equipment with both input and output voltage ratings of 1500 volts and below. This type of equipment is covered by the Standard for Adjustable Speed Electrical Power Drive Systems – Part 5-1: Safety Requirements – Electrical, Thermal and Energy, UL 61800-5-1.

  • TABLE OF CONTENTS
    Expand All

    • Cover
    • Transmittal
    • Table of Contents
      • Body
        • INTRODUCTION
          • 1 Scope
          • 2 Glossary
          • 3 Components
          • 4 Units of Measurement
        • RATING
          • 5 General
        • CONSTRUCTION
          • 6 General
          • 7 Enclosure
            • 7.1 General
            • 7.2 Ventilation openings
            • 7.3 Environmental rating related enclosure requirements
            • 7.4 Protection against corrosion
          • 8 Arrangement of Components
          • 9 Guarding and Accessiblity of Live Parts
          • 10 Grounding and Bonding
          • 11 Protective Devices
          • 12 Overload Relays
          • 13 Isolating Means
          • 14 Interlocking
          • 15 Automatic Restarting
          • 16 Internal Wiring
          • 17 Voltage Dividers
          • 18 Terminals and Connections
          • 19 Spacings
            • 19.1 General
            • 19.2 Circuits connected to the medium voltage line
            • 19.3 Circuits isolated from the medium voltage line
            • 19.4 Insulating material used as a barrier in lieu of spacings
            • 19.5 Clamped insulating joints in lieu of spacings
            • 19.6 Voltage dividers and other circuits provided with solid insulation
          • 20 Means for Switching
          • 21 Capacitors
          • 22 Control Circuits
          • 23 Bypass Circuits
            • 23.1 Bypass contactors rated 15 kV and less
            • 23.2 Bypass Circuits Rated Over 15 kV
          • 24 Gate Drive Circuits
          • 25 Transformers, Reactors, and Voltage Sensing Devices
          • 26 Cord-Connected Programming and Diagnostic Units
          • 27 Accessories
          • 28 Cooling Systems
        • PERFORMANCE
          • 29 General
          • 30 Temperature Test
            • 30.1 General
            • 30.2 Test conditions
          • 31 Dielectric Voltage-Withstand Test
            • 31.1 General
            • 31.2 Meters
            • 31.3 Test procedure
          • 32 Switching Capability Test - Isolating Means
          • 33 Short Circuit Interruption Test
            • 33.1 General requirements
            • 33.2 Interruption ratings
            • 33.3 Branch circuit short circuit protection requirements
          • 34 Impulse Withstand Test
            • 34.1 General
            • 34.2 Impulse voltage withstand test methods
            • 34.3 Evaluation
          • 35 Calibration Tests – Overload
          • 36 Solid State Motor Protection Tests
            • 36.1 Solid state motor overload protection test
            • 36.2 Thermal memory retention test (shutdown)
            • 36.3 Thermal memory retention test (loss of power)
            • 36.4 Speed sensitivity test
          • 37 Operation Tests
            • 37.1 General
            • 37.2 Single phasing
            • 37.3 Inoperative blower motor
            • 37.4 Clogged filter
            • 37.5 Current limiting control
            • 37.6 Loss of cooling medium circulation test
            • 37.7 Input phase reversal
            • 37.8 Acceptance criteria
          • 38 Hydrostatic Pressure Test
          • 39 Breakdown of Components Test
          • 39A Capacitor Discharge Test
          • 40 Mechanical Operation and Interlock Integrity Test
          • 41 Accessory Installation Test
        • MARKINGS
          • 42 General
          • 43 Overload, Overcurrent, Overtemperature, and Overspeed Protection Markings
          • 44 Branch Circuit Short Circuit Protection Markings
          • 45 Cautionary Markings
          • 46 Instructions and Markings Pertaining to Enclosures
            • 46.1 Permanence of marking
            • 46.2 Details
          • 47 Instructions and Markings Pertaining to Accessories
        • MANUFACTURING AND PRODUCTION LINE TEST
          • 48 Burn-In and Diagnostic Tests
    • APPENDIX A