UL 731
Standard for Oil-Fired Unit Heaters

DETAILS
Edition Number:6SCC Approved:--
Edition Date:2018-01-31DOD Approved: --
Price Code:AANSI Approved: 2016-11-22
Type:ulstd

  • SCOPE

    1 Scope

    1.1 These requirements apply to oil-fired unit heaters as defined herein. Unit heaters designed to supply heated air through ducts are covered in the Standard for Oil-Fired Central Furnaces, UL 727.

    1.2 The oil-burning equipment covered by these requiremetns are intended for installation in accordance with the National Fire Protection Association Standard for the Installation of Oil Burning Equipment, NFPA 31, the International Mechanical Code and the Uniform Mechanical Code.

    1.3 If a value for measurement is followed by a value in other units in parentheses, the second value may be only approximate. The first stated value is the requirement.

  • TABLE OF CONTENTS
    Expand All

    • Cover
    • Transmittal
    • Table of Contents
      • Body
        • INTRODUCTION
          • 1 Scope
          • 2 Glossary
          • 3 Components
        • CONSTRUCTION
          • 4 Assembly
          • 5 Burners
          • 6 Accessibility for Servicing
          • 7 Disposal of Combustion Products
          • 8 Base
          • 9 Casing
          • 10 Radiation Shields and Materials in Air-Handling Compartments
          • 11 Air Filter
          • 12 Combustion Chamber
          • 13 Radiator
          • 14 Heating Surface Joints
          • 15 Baffles
          • 16 Flue Collar
          • 17 Damper and Draft Regulator
          • 18 Controls
            • 18.1 Application
            • 18.2 Limit control
          • 19 Field Wiring
            • 19.1 General
            • 19.2 Leads and terminals
          • 20 Internal Wiring
            • 20.1 General
            • 20.2 Methods
            • 20.3 Short circuit protection
          • 21 Separation of Circuits
          • 22 Bonding for Grounding
          • 23 Electrical Components – General
          • 24 Mounting of Electrical Components
          • 25 Electrical Enclosures
            • 25.1 General
            • 25.2 Doors and covers
            • 25.3 Field wiring system connection
          • 26 Motors and Motor Overload Protection
          • 27 Overcurrent Protection of High-Voltage Control-Circuit Conductors
            • 27.1 General
            • 27.2 Direct-connected high-voltage control circuit
            • 27.3 Tapped high-voltage control circuits
            • 27.4 Overcurrent-protective devices
          • 28 Overcurrent Protection of Transformers
            • 28.1 High-voltage transformers
            • 28.2 Low-voltage transformers
            • 28.3 Overcurrent protective devices
          • 29 Switches and Controllers
          • 30 Capacitors
          • 31 Electrical Insulating Material
          • 32 High-Voltage Circuits Spacings
          • 33 Low-Voltage Circuits Spacings
        • PROTECTION OF USERS AND SERVICE PERSONNEL
          • 34 General
        • PERFORMANCE
          • 35 General
          • 36 Test Installation – Floor-Mounted Heaters
            • 36.1 Enclosure
            • 36.2 Chimney connector
            • 36.3 Air outlet and inlet
          • 37 Test Installation – Suspended Type Heaters
            • 37.1 Enclosure
            • 37.2 Chimney connector
            • 37.3 Air outlet and inlet
          • 38 Instrumentation
            • 38.1 Draft
            • 38.2 Fuel input
            • 38.3 Power measurement
            • 38.4 Speed measurement
            • 38.5 Temperature measurement
          • 39 Initial Test Conditions
            • 39.1 General
            • 39.2 Heater equipped with mechanical atomizing burner
          • 40 Combustion Test – Burner and Heater
          • 41 Continuous Operation Tests
          • 42 Limit Control Cutout Test
          • 43 Continuity of Operation Test
          • 44 Temperature Test
          • 45 Continuous Operation Temperatures
          • 46 Fan Failure Test
          • 47 Stalled Fan Motor Test
          • 48 Blocked Inlet Test
          • 49 Short Circuit Test
          • 50 Overload Test, High-Voltage Transformers
          • 51 Burnout Test, High-Voltage Transformers
          • 52 Dielectric Voltage-Withstand Test
        • MANUFACTURING AND PRODUCTION TESTS
          • 53 General
        • MARKING
          • 54 General
        • INSTALLATION INSTRUCTIONS
          • 55 General
    • APPENDIX A