1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 733 Oil-Fired Air Heaters and Direct-Fired HeatersUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHOR
2、IZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Oil-Fired Air Heaters and Direct-Fired Heaters, UL 733 Fourth Edition, Dated August 25, 1993 Summary of Topics This revision to UL 733 is being issued to remove the reference to the withdrawal date of
3、 UL 873 and to address universal upkeep of UL Standards for Safety. These revisions are considered to be non-substantive and not subject to ULs STP process. Text that has been changed in any manner or impacted by ULs electronic publishing system is marked with a vertical line in the margin. Changes
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9、ct, except for those paragraphs, sections, tables, gures, and/or other elements of the Standard having future effective dates as indicated in the note following the affected item. The prior text for requirements that have been revised and that have a future effective date are located after the Stand
10、ard, and are preceded by a SUPERSEDED REQUIREMENTS notice. OCTOBER 9, 2013 UL 733 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL OCTOBER 9, 2013 UL 733 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTI
11、ON OR DISTRIBUTION WITHOUT PERMISSION FROM UL AUGUST 25, 1993 (Title Page Reprinted: October 9, 2013) 1 UL 733 Standard for Oil-Fired Air Heaters and Direct-Fired Heaters First Edition August, 1955 Second Edition May, 1973 Third Edition July, 1975 Fourth Edition August 25, 1993 This UL Standard for
12、Safety consists of the Fourth Edition including revisions through October 9, 2013. Comments or proposals for revisions on any part of the Standard may be submitted to UL at any time. Proposals should be submitted via a Proposal Request in ULs On-Line Collaborative Standards Development System (CSDS)
13、 at http:/. ULs Standards for Safety are copyrighted by UL. Neither a printed nor electronic copy of a Standard should be altered in any way. All of ULs Standards and all copyrights, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2013 U
14、NDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL DECEMBER 13, 2005 OIL-FIRED AIR HEATERS AND DIRECT-FIRED HEATERS - UL 733 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR D
15、ISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .5 2 General 5 3 Units of Measurement .6 3A Undated References .6 4 Glossary .6 5 Instructions .9 CONSTRUCTION 6 Assembly .10 7 Accessibility for Servicing .11 8 Disposal of Combustion Products 11 9 Casing 12 10 Radiation Shields o
16、r Liners and Materials in Air Handling Compartments 12 11 Air Filter .13 12 Integral Oil Tanks .13 13 Combustion Chamber .14 14 Radiator .14 15 Heating Surface Joints 14 16 Baffles.15 17 Flue Collar .15 18 Damper and Draft Regulator .16 19 Ducts 16 20 Controls .16 20.1 Application 16 20.2 Limit cont
17、rol 16A 20.3 Primary safety control .16A 21 Field Wiring .16B 21.1 General 16B 21.2 Leads and terminals 18 22 Internal Wiring 19 22.1 General .19 22.2 Methods 20 22.3 Short circuit protection 23 23 Separation of Circuits .23 24 Bonding for Grounding 25 ELECTRICAL COMPONENTS 25 General 28 26 Mounting
18、 of Electrical Components .29 27 Electrical Enclosures 29 27.1 General .29 27.2 Doors and covers 34 27.3 Field wiring system connection .35 28 Motors and Motor Overload Protection 36 29 Switches and Controllers 41 30 Capacitors .41 DECEMBER 13, 2005 OIL-FIRED AIR HEATERS AND DIRECT-FIRED HEATERS - U
19、L 733 2AUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 31 Insulating Material 42 SPACINGS 32 High-Voltage Circuits 42 33 Low-Voltage Circuits 44 PROTECTION OF USERS AND SERVICE PERSONNEL 34 General 44 PERFORMANCE 35 General 47 36 Test Insta
20、llation .48 37 Instrumentation 48A 37.1 Draft 48A 37.2 Fuel input 48B 37.3 Power measurement 48B 37.4 Speed measurement 48B 37.5 Static pressure .51 37.6 Temperature measurement 51 38 Initial Test Conditions .53 38.1 General .53 38.2 Heater equipped with mechanical atomizing burner .54 38.3 Heater e
21、quipped with vaporizing burner .54 39 Combustion Test Burner and Heater 55 40 Operation Tests 55 41 Limit Control Cutout Test 55 42 Continuity of Operation Test .56 43 Temperature Tests 56 44 Continuous Operation Temperature Test 60 45 Blocked Inlet Test .61 46 Fan Failure Test 61 47 Stalled Fan Mot
22、or Test 62 48 Blocked Outlet Test .62 49 Maximum Wall Temperature Test .62 50 Short Circuit Test .63 51 Dielectric Withstand Test 66 52 Leakage Current Test .66 MANUFACTURING AND PRODUCTION TESTS 53 General 69 54 Production Line Dielectric Withstand Test 70 55 Production Line Grounding Continuity Te
23、st .70 MARKING 56 General 71 DECEMBER 13, 2005 OIL-FIRED AIR HEATERS AND DIRECT-FIRED HEATERS - UL 733 2BUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONSTRUCTION OUTDOOR USE EQUIPMENT 57 General 73 58 Enclosure 73 58.1 General .73 58.2 C
24、orrosion protection 74 59 Wiring .76 PERFORMANCE OUTDOOR USE EQUIPMENT 60 Rain Test 76 61 Chromic Acid Dropping Test .80 62 Gaskets .81 MARKING OUTDOOR USE EQUIPMENT 63 General 83 APPENDIX A Standards for Component.A1 DECEMBER 13, 2005 OIL-FIRED AIR HEATERS AND DIRECT-FIRED HEATERS - UL 733 3UL COPY
25、RIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL This page intentionally left blank. DECEMBER 13, 2005 OIL-FIRED AIR HEATERS AND DIRECT-FIRED HEATERS - UL 733 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT P
26、ERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements apply to oil-red air heaters and direct-red heaters. 1.2 Requirements for the installation and use of oil-burning equipment are included in the Standard for the Installation of Oil-Burning Equipment, NFPA 31. 1.3 Deleted December 13, 2005
27、 2 General 2.1 The term appliance refers to any equipment covered by this Standard. 2.2 Values stated without parentheses are the requirement. Values in parentheses are explanatory or approximate information. 2.3 Except as indicated in 2.4, a component of a product covered by this standard shall com
28、ply with the requirements for that component. See Appendix A for a list of standards covering components generally used in the products covered by this standard. 2.4 A component is not required to comply with a specic requirement that: a) Involves a feature or characteristic not required in the appl
29、ication of the component in the product covered by this standard, or b) Is superseded by a requirement in this standard. 2.5 A component shall be used in accordance with its rating established for the intended conditions of use. 2.6 Specic components are incomplete in construction features or restri
30、cted in performance capabilities. Such components are intended for use only under limited conditions, such as certain temperatures not exceeding specied limits, and shall be used only under those specic conditions. DECEMBER 13, 2005 OIL-FIRED AIR HEATERS AND DIRECT-FIRED HEATERS - UL 733 5UL COPYRIG
31、HTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 3 Units of Measurement 3.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory or approximate information. 3A Undated References 3A.1 Any undated reference to a c
32、ode or standard appearing in the requirements of this standard shall be interpreted as referring to the latest edition of that code or standard. 3A.1 added December 13, 2005 4 Glossary 4.1 For the purpose of this Standard the following denitions apply. 4.2 AIR HEATER An indirect-red vented appliance
33、 intended to supply heated air for space heating and other purposes, but not intended for permanent installation. This denition does not include central furnaces, kerosene stoves, oil-burning stoves, or unit heaters. 4.3 AIR SHUTTER An adjustable device for varying the size of the air inlet or inlet
34、s regulating primary and/or secondary air. 4.4 ANTIFLOODING DEVICE A primary safety control which causes the fuel ow to be shut off upon a rise in fuel level or upon receiving excess fuel, and which operates before the hazardous discharge of fuel can occur. 4.5 APPLIANCE FLUE The ue passages with in
35、 the appliance. 4.6 AUTOMATICALLY LIGHTED APPLIANCE An appliance in which fuel to the main burner is normally turned on and ignited automatically. 4.7 BAFFLE An object placed in an appliance to direct the ow of air or ue gases. 4.8 BURNER, MECHANICAL-ATOMIZING TYPE A power-operated burner which prep
36、ares and delivers the oil and all or part of the air by mechanical process in controllable quantities for combustion. Some examples are air atomizing, high and low pressure atomizing, horizontal rotary, vertical rotary atomizing, and vertical rotary wall-ame burners. 4.9 BURNER, MECHANICAL DRAFT TYP
37、E A burner which includes a power-drive fan, blower, or other mechanism as the principal means for supplying air for combustion. 4.10 BURNER, NATURAL DRAFT TYPE A burner which depends principally upon the natural draft created in the ue to induce into the burner the air required for combustion. 4.11
38、 BURNER, VAPORIZING TYPE A burner consisting of an oil-vaporizing bowl or other receptacle to which liquid fuel may be fed in controllable quantities; the heat of combustion being used to vaporize the fuel, with provision for admitting air and mixing it with the oil vapor in combustible proportions.
39、 4.12 CASING An enclosure forming the outside of the appliance, no parts of which are likely to be subjected to intense heat. DECEMBER 13, 2005 OIL-FIRED AIR HEATERS AND DIRECT-FIRED HEATERS - UL 733 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION
40、FROM UL 4.13 CENTRAL HEATING APPLIANCE A stationary indirect-red vented appliance comprising the following classes: boilers, central furnaces, oor furnaces, and recessed heaters. A oor-mounted unit heater to be connected to a duct system is categorized also as a central heating appliance. 4.14 COMBU
41、STIBLE MATERIAL Combustible material as pertaining to materials adjacent to or in contact with heat-producing appliances, chimney connectors and vent connectors, steam and hot-water pipes, and warm-air ducts means material made of or surfaced with wood, compressed paper, plant bers, or other materia
42、l that will ignite and burn. Such material shall be considered as combustible even though ameproofed, re-retardant treated, or plastered. 4.15 COMBUSTION CHAMBER The portion of an appliance within which combustion occurs. 4.16 CONSTANT-LEVEL VALVE A device for maintaining within a reservoir a consta
43、nt level of fuel for delivery to the burner. DECEMBER 13, 2005 OIL-FIRED AIR HEATERS AND DIRECT-FIRED HEATERS - UL 733 6AUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL DECEMBER 13, 2005 OIL-FIRED AIR HEATERS AND DIRECT-FIRED HEATERS - UL 73
44、3 6B No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 4.17 CONTROL, LIMIT An automatic safety control responsive to changes in liquid level, pressure, or temperature for limiting the operation of the controlled equipment.
45、4.18 CONTROL, SAFETY Automatic controls, including relays, switches, and other auxiliary equipment used in conjunction therewith to form a safety control system, which are intended to prevent unsafe operation of the controlled equipment. 4.19 CONTROL, PRIMARY SAFETY The automatic safety control inte
46、nded to prevent abnormal discharge of oil at the burner in case of ignition failure of ame failure. 4.20 CONTROL, SAFETY COMBUSTION A primary safety control responsive directly to ame properties; sensing the presence of ame and causing fuel to be shut off in event of ame failure. 4.21 DAMPER A valve
47、 or plate for regulating draft or ow of ue gases. A damper is generally considered as being located on the downstream side of the combustion chamber, usually in a ue passage of the appliance or in the chimney connector. 4.22 DAMPER, AUTOMATICALLY OPERATED A damper operated by an automatic control. 4
48、.23 DAMPER, MANUALLY OPERATED An adjustable damper manually set and locked in the desired position. 4.24 DIRECT-FIRED HEATER A heater in which combustion products or ue gases are mixed with the air being heated, such as a salamander. 4.25 DRAFT REGULATOR A device which functions to maintain a desire
49、d draft in the appliance by automatically reducing the chimney draft to the desired value. 4.26 ELECTRICAL CIRCUITS: a) High-Voltage Circuit A circuit involving a potential of not more than 600 volts and having circuit characteristics in excess of those of a low-voltage circuit; b) Low-Voltage Circuit A circuit involving a potential of not more than 30 volts alternating-current (42.4 peak) or direct current and supplied by: 1) A Cla
