UL 1004-3
Standard for Thermally Protected Motors

DETAILS
Edition Number:2SCC Approved:--
Edition Date:2015-02-27DOD Approved: --
Price Code:AANSI Approved: 2015-02-25
Type:ulstd

  • SCOPE

    1 Scope

    1.1 This Standard is intended to be read together with the Standard for Rotating Electrical Machines – General Requirements, UL 1004-1. The requirements in this Standard supplement or amend the requirements in UL 1004-1. The requirements of UL 1004-1 apply unless modified by this Standard.

    1.2 This Standard applies to motors that rely upon a device (thermal motor protector) to prevent overheating under at least one operating condition. These motors shall be identified as thermally protected motors.

    1.3 This Standard applies to motors protected either by electromechanical thermal motor protectors or solid-state thermal motor protectors.

    1.4 This Standard applies to impedance protected motors where the manufacturer has provided a supplementary thermal motor protector.

    1.5 The requirements in this Standard are intended to evaluate a specific motor/protector combination. When the motor, the protector, or the motor/protector combination is changed, the combination shall be reevaluated.

    1.6 This Standard applies to motors provided with coordinated protection where Locked Rotor protection is provided by one means and Running Heating protection is provided by another as required by 7.11.

  • TABLE OF CONTENTS
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    • Cover
    • Transmittal
    • Table of Contents
      • Body
        • INTRODUCTION
          • 1 Scope
          • 2 Glossary
        • CONSTRUCTION
          • 3 Spacings
          • 4 Thermal Protection Systems
          • 5 Intentionally Weak Trace (IWT)
        • PERFORMANCE
          • 6 General
          • 7 Motors Additionally Provided with Electronic Protection
          • 8 Locked Rotor Temperature Test
            • 8.1 General
            • 8.2 Automatically reset protectors
            • 8.3 Manually reset protectors
            • 8.4 Thermal cutoffs
            • 8.5 Self-holding protectors
            • 8.6 Single-operation devices
          • 9 Locked Rotor Endurance Test
            • 9.1 General
            • 9.2 Automatically reset protectors
            • 9.3 Manually reset protectors
            • 9.4 Self-holding protectors
            • 9.5 Self-holding protector cold reset
          • 10 Running Heating Temperature Test
            • 10.1 General
            • 10.2 Continuous duty motors
            • 10.3 Polyphase motors
            • 10.4 Ultimate trip current
            • 10.5 Intermittent duty motors
            • 10.6 Air-over motors
            • 10.7 Polyphase air-over motors
          • 11 Intentionally Weak Trace (IWT) Tests
            • 11.1 General
            • 11.2 Safety function
            • 11.3 Rating
            • 11.4 Full range
            • 11.5 Evaluation of functionality 1 IWT
            • 11.6 Evaluation of functionality 2-4 IWT
        • MARKINGS
          • 12 General
        • INSTRUCTIONS
          • 13 General