UL 1741
Standard for Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources

DETAILS
Edition Number:2SCC Approved:--
Edition Date:2010-01-28DOD Approved: --
Price Code:CANSI Approved: --
Type:ulstd

  • SCOPE

    1 Scope

    1.1 These requirements cover inverters, converters, charge controllers, and interconnection system equipment (ISE) intended for use in stand-alone (not grid-connected) or utility-interactive (grid-connected) power systems. Utility-interactive inverters, converters, and ISE are intended to be operated in parallel with an electric power system (EPS) to supply power to common loads.

    1.2 For utility-interactive equipment, these requirements are intended to supplement and be used in conjunction with the Standard for Interconnecting Distributed Resources With Electric Power Systems, IEEE 1547, and the Standard for Conformance Test Procedures for Equipment Interconnecting Distributed Resources with Electric Power Systems, IEEE 1547.1.

    1.3 These requirements cover AC modules that combine flat-plate photovoltaic modules and inverters to provide AC output power for stand-alone use or utility-interaction, and power systems that combine other alternative energy sources with inverters, converters, charge controllers, and interconnection system equipment (ISE), in system specific combinations.

    1.4 These requirements also cover power systems that combine independent power sources with inverters, converters, charge controllers, and interconnection system equipment (ISE) in system specific combinations.

    1.5 The products covered by these requirements are intended to be installed in accordance with the National Electrical Code, NFPA 70.

  • TABLE OF CONTENTS
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    • Cover
    • Transmittal
    • Table of Contents
      • Body
        • INTRODUCTION
          • 1 Scope
          • 2 Glossary
          • 3 General
            • 3.1 Components
            • 3.2 Units of measurement
            • 3.3 References
        • CONSTRUCTION
          • 4 General
          • 5 Frame and Enclosure
            • 5.1 General
            • 5.2 Access covers
            • 5.3 Cast metal enclosures
            • 5.4 Sheet metal enclosures
            • 5.5 Nonmetallic enclosures
            • 5.6 Openings covered by glass
            • 5.7 Openings for wiring system connections
            • 5.8 Openings for ventilation
            • 5.9 Environmental rated enclosures
          • 6 Protection Against Corrosion
          • 7 Mechanical Assembly
          • 8 Mounting
          • 9 Protection of Users – Accessibility of Uninsulated Live Parts
          • 10 Protection of Service Personnel
          • 11 Electric Shock
            • 11.1 Voltage
            • 11.2 Stored energy
          • 12 Switches and Controls
          • 13 Disconnect Devices
          • 14 AC Output Connections
            • 14.1 Stand-alone inverters
            • 14.2 Utility-interactive inverters
          • 15 Receptacles
          • 16 Supply Connections
            • 16.1 General
            • 16.2 Wiring terminals
            • 16.3 Wiring leads
            • 16.4 Wiring compartments
            • 16.5 Openings for conduit or cable connection
            • 16.6 Openings for class 2 circuit conductors
          • 17 Wire-Bending Space
          • 18 Equipment Grounding
            • 18.1 General
            • 18.2 Grounding electrode terminal
          • 19 AC Output Circuit Grounded Conductor
          • 20 Internal Bonding for Grounding
          • 21 Internal Wiring
            • 21.1 General
            • 21.2 Protection of wiring
            • 21.3 Electrical connections
          • 22 Live Parts
          • 23 Separation of Circuits
            • 23.1 Factory wiring
            • 23.2 Field wiring
            • 23.3 Separation barriers
          • 24 Spacings
            • 24.1 General
            • 24.2 Insulating liners and barriers
          • 25 Alternate Spacings – Clearances and Creepage Distances
          • 26 Insulating Materials
            • 26.1 General
            • 26.2 Barriers
          • 27 Capacitors
          • 28 Isolated Accessible Signal Circuits
          • 29 Control Circuits
          • 30 Overcurrent Protection
            • 30.1 General
            • 30.2 Control circuit overcurrent protection
            • 30.3 Output ac power circuit overcurrent protection
            • 30.4 Battery circuits
          • 31 DC Ground Fault Detector/Interrupter
          • 32 Printed-Wiring Boards
          • 33 External Transformers
        • PROTECTION AGAINST RISKS OF INJURY TO PERSONS
          • 34 General
          • 35 Enclosures and Guards
          • 36 Moving Parts
          • 37 Switches and Controls
          • 38 Mounting
        • OUTPUT POWER CHARACTERISTICS AND UTILITY COMPATIBILITY
          • 39 General
          • 40 Utility Interaction
        • PERFORMANCE
          • 41 General
          • 42 Maximum-Voltage Measurements
          • 43 Temperature
          • 44 Dielectric Voltage-Withstand Test
          • 45 Output Power Characteristics
            • 45.1 General
            • 45.2 Output ratings
            • 45.3 Input range
            • 45.4 Harmonic distortion
          • 46 Utility Compatibility
          • 47 Abnormal Tests
            • 47.1 General
            • 47.2 Output overload test
            • 47.3 Short-circuit test
            • 47.4 DC input miswiring test
            • 47.5 Ventilation test
            • 47.6 Component short- and open-circuit
            • 47.7 Load transfer test
            • 47.8 Loss of control circuit
          • 48 Grounding Impedance Test
          • 49 Overcurrent Protection Calibration Test
          • 50 Strain Relief Test
          • 51 Reduced Spacings on Printed Wiring Boards Tests
            • 51.1 General
            • 51.2 Dielectric voltage-withstand test
            • 51.3 Shorted trace test
          • 52 Bonding Conductor Test
          • 53 Voltage Surge Test
          • 54 Calibration Test
          • 55 Overvoltage Test
          • 56 Current Withstand Test
          • 57 Capacitor Voltage Determination Test
          • 58 Stability
          • 59 Static Load
          • 60 Compression Test
          • 61 Rain and Sprinkler Tests
            • 61.1 General
            • 61.2 Rain test
            • 61.3 Sprinkler test
        • RATING
          • 62 Details
        • MARKING
          • 63 Details
          • 64 Cautionary Markings
          • 65 Equipment Information and Instructions
            • 65.1 Separation of information
            • 65.2 Operating and installation instructions
          • 66 Important Safety Instructions
        • MANUFACTURING AND PRODUCTION TESTS
          • 67 Dielectric Voltage-Withstand Test
          • 68 Utility Voltage and Frequency Variation Test
        • CHARGE CONTROLLERS
          • INTRODUCTION
          • 69 General
          • CONSTRUCTION
          • 70 General
          • PERFORMANCE
          • 71 General
          • 72 Normal Operations
          • 73 Temperature
          • 74 Temperature Compensation
          • 75 Connection Sequence
          • 76 Abnormal Tests
            • 76.1 General
            • 76.2 Input and output faults
            • 76.3 Charge controller miswiring
            • 76.4 Low-voltage disconnect
          • MARKING
          • 77 Cautionary Markings
          • 78 Details
          • 79 Important Safety Instructions
        • AC MODULES
          • INTRODUCTION
          • 80 General
          • CONSTRUCTION
          • 81 General
          • PERFORMANCE
          • 82 General
          • 83 AC Module Inverter Securement Test
          • RATING
          • 84 General
          • MARKING
          • 85 Details
          • 86 Important Safety Instructions
    • GRID SUPPORT UTILITY INTERACTIVE INVERTERS AND CONVERTERS
    • APPENDIX A