UL 295-2017 UL Standard for Safety for Commercial-Industrial Gas Burners (Second Edition).pdf

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1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 295 Commercial-Industrial Gas Burners STANDARD FOR SAFETYUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT

2、 AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Commercial-Industrial Gas Burners, UL 295 Second Edition, Dated February 8, 2017 Summary of Topics This new edition of ANSI/UL 295 is being issued to add requirements for gas assist (pre-mix) b

3、urners and to clarify requirements for high gas pressure switch. Editorial revisions have also been incorporated. The new and revised requirements are substantially in accordance with Proposal(s) on this subject dated August 26, 2016 and December 9, 2016. All rights reserved. No part of this publica

4、tion may be reproduced, stored in a retrieval system, or transmitted in any form by any means, electronic, mechanical photocopying, recording, or otherwise without prior permission of UL. UL provides this Standard as is without warranty of any kind, either expressed or implied, including but not lim

5、ited to, the implied warranties of merchantability or tness for any purpose. In no event will UL be liable for any special, incidental, consequential, indirect or similar damages, including loss of prots, lost savings, loss of data, or any other damages arising out of the use of or the inability to

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8、m. FEBRUARY 8, 2017 UL 295 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL FEBRUARY 8, 2017 UL 295 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL FEBRUARY

9、 8, 2017 1 UL 295 Standard for Commercial-Industrial Gas Burners First Edition December, 2007 Second Edition February 8, 2017 This ANSI/UL Standard for Safety consists of the Second Edition. The most recent designation of ANSI/UL 295 as an American National Standard (ANSI) occurred on February 8, 20

10、17. ANSI approval for a standard does not include the Cover Page, Transmittal Pages, and Title Page. 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 Develop

11、ment System (CSDS) at https:/. 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 U

12、L. COPYRIGHT 2017 UNDERWRITERS LABORATORIES INC. ANSI/UL 295-2017UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL FEBRUARY 8, 2017 COMMERCIAL-INDUSTRIAL GAS BURNERS - UL 295 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FUR

13、THER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .6 2 Components6 3 Units of Measurement .6 4 Undated References 7 5 Glossary .7 CONSTRUCTION 6 General.12 7 Corrosion Protection .12 8 Protection of Users and Service Personnel .13 9 Enclosures 17 9.1 General

14、17 9.2 Accessibility of uninsulated live parts and lm-coated wire - general .21 9.3 Doors and covers .26 9.4 Field wiring system connection 27 10 General Components and Devices 28 CONSTRUCTION ELECTRICAL COMPONENTS 11 Field Wiring 28 11.1 General .28 11.2 Leads and terminals 31 12 Internal Wiring32

15、12.1 General .32 12.2 Methods 33 12.3 Short-circuit protection 36 13 Separation of Circuits .37 14 Bonding for Grounding 38 15 Mounting of Electrical Components .42 16 Motors.43 16.1 General .43 16.2 Motor overload protection .45 17 Overcurrent Protection of High-Voltage Control-Circuit Conductors .

16、48 17.1 General .48 17.2 Direct-connected high-voltage control circuit .48 17.3 Tapped high-voltage control circuits 48 17.4 Overcurrent-protective devices .49 18 Overcurrent Protection of Transformers50 18.1 High-voltage transformers General50 18.2 High-voltage transformers Thermal protection 50 18

17、.3 High-voltage transformers Overcurrent protection.51 18.4 Low-voltage transformers General 51 18.5 Low-voltage transformers Overcurrent protective devices 52 19 Switches and Controllers 52 20 Capacitors 53 21 Electrical Insulating Materials.54 FEBRUARY 8, 2017 COMMERCIAL-INDUSTRIAL GAS BURNERS - U

18、L 295 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONSTRUCTION ELECTRICAL SPACINGS 22 High-Voltage Circuits .54 23 Low-Voltage Circuits 55 CONSTRUCTION CONTROLS AND SAFETY DEVICES 24 Assembly 56 25 Accessibility for Servicing .58 26 Fan

19、 Housings and Air Tubes 58 27 Combustion Air Control .58 28 Fittings, and Piping and Tubing 60 29 Valves and Regulators 63 29.1 Automatic safety shutoff valves General .63 29.2 Manually operated valves .64 29.3 Gas pressure regulators.65 30 Bleeds and Vents .65 31 Gauges66 32 Ignition Systems Genera

20、l 66 33 Electric High-Tension Ignition 68 33.1 Spark igniters 68 33.2 Electrode and bus bars .68 33.3 Insulators .68 33.4 Leads .69 33.5 Transformers 69 34 Gas Pilots .70 35 Control Applications 71 36 Primary Safety Controls .72 37 Purge and Combustion Air Monitoring Controls 75 38 Gas Pressure Cont

21、rols 76 39 Interlocks 76 40 Combination Gas-Oil Burners 76 PERFORMANCE 41 Test Methods 77 41.1 Firing conditions77 41.2 Temperature measurements .78 41.3 Test installation 78 41.4 Test voltage .79 42 Power Input Test .79 43 Combustion Test .79 44 Endurance Test 80 45 Combustion Air Failure Test80 46

22、 Undervoltage Test 81 47 Power Interruption Test81 48 Pilot Supervision Test .82 49 Ignition Test, Gas-Electric High Tension .82 50 Ignition Test, Multiple Burner .83 51 Delayed Ignition Test83 52 Temperature Test.84 53 Strain Relief Test .88 54 Fuel Changeover Test Combination Gas-Oil-Fired Burner

23、Assemblies .88 FEBRUARY 8, 2017 COMMERCIAL-INDUSTRIAL GAS BURNERS - UL 295 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 55 Short-Circuit Test 88 56 Overload Test, High-Voltage Transformers 91 57 Burnout Test, High-Voltage Transformers .9

24、1 58 Dielectric Voltage-Withstand Test .92 58.1 General .92 58.2 Dielectric withstand Ignition assembly .93 58.3 Dielectric withstand Electrode insulator 93 MANUFACTURING AND PRODUCTION TESTS 59 General .93 60 Production Line Dielectric Voltage-Withstand Test 94 MARKINGS 61 General95 62 Nameplate .9

25、5 63 Supplemental Marking.96 INSTRUCTIONS 64 General98 FEBRUARY 8, 2017 COMMERCIAL-INDUSTRIAL GAS BURNERS - UL 295 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover commercial-industrial gas b

26、urners with input ratings over 400,000 Btu per hour (117.23 kW) intended for installation in heating equipment such as, but not limited to, appliances, furnaces, heaters, ovens, water heaters, and incinerators. These gas burners are required to be equipped with integral automatic primary safety cont

27、rols to restrict the abnormal ow of gaseous fuel in case of ignition failure and/or ame failure. 1.2 Additional installation and operation requirements are available for commercial-industrial gas burners, as dened by the National Fuel Gas Code, NFPA 54 and by the Liqueed Petroleum Gas Code, NFPA 58,

28、 as applicable. 2 Components 2.1 Except as indicated in 2.2, a component of a product covered by this standard shall comply with the requirements for that component. See the individual sections of this Standard for component requirements. 2.2 A component is not required to comply with a specic requi

29、rement that: a) Involves a feature or characteristic not required in the application of the component in the product covered by this standard, or b) Is superseded by a requirement in this standard. 2.3 A component shall be used in accordance with its rating established for the intended conditions of

30、 use. 2.4 Specic components are incomplete in construction features or restricted 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. 3 Units

31、of Measurement 3.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory or approximate information. FEBRUARY 8, 2017 COMMERCIAL-INDUSTRIAL GAS BURNERS - UL 295 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION

32、FROM UL 4 Undated References 4.1 Any undated reference to a code or standard appearing in the requirements of this standard shall be interpreted as referring to the latest edition of that code or standard. 5 Glossary 5.1 For the purpose of this standard, the following denitions apply. 5.2 AIR SHUTTE

33、R An adjustable device for varying the size of the air inlet or inlets regulating primary or secondary air. 5.3 AIR SHUTTER, AUTOMATICALLY OPERATED An air shutter operated by an automatic control. 5.4 ALUMINUM-COATED STEEL An aluminum coated steel in which the bond between the steel and the aluminum

34、 is an iron-aluminum alloy. 5.5 BURNER, GAS A device for the nal conveyance of the gas, or a mixture of gas and air, to the combustion zone. 5.6 BURNER, AUTOMATICALLY LIGHTED One where fuel to the main burner is normally turned on and ignited automatically. 5.7 BURNER, MANUALLY LIGHTED One where fue

35、l to the main burner is turned on only by hand and ignited under supervision. 5.8 BURNER, MECHANICAL-DRAFT A burner that includes a power-driven fan, blower, or other mechanism as the principal means for supplying air for combustion. 5.9 BURNER, NATURAL-DRAFT A burner that depends principally upon t

36、he natural draft created in the ue to induce into the burner the air required for combustion. 5.10 BURNER HEAD That portion of a burner beyond the outlet end of the mixer tube which contains the ports. 5.11 COMBUSTIBLE AND NON-COMBUSTIBLE Refer to the Standard Glossary of Terms Relating to Chimneys,

37、 Vents, and Heat-Producing Appliances, ANSI/NFPA 97. 5.12 COMBUSTIBLE 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, refers to material made of or surfaced with wood

38、, compressed paper, plant bers, or other material that will ignite and burn. Such material shall be considered as combustible even through ameproofed, re-retardant treated, or plastered. 5.13 COMBUSTION As used herein, the rapid oxidation of fuel accompanied by the production of heat, or heat and li

39、ght. Complete combustion of a fuel is possible only in the presence of an adequate supply of oxygen. 5.14 COMBUSTION CHAMBER The portion of an appliance within which combustion occurs. 5.15 COMBUSTION DETECTOR That part of a primary safety control which is responsive directly to ame properties. FEBR

40、UARY 8, 2017 COMMERCIAL-INDUSTRIAL GAS BURNERS - UL 295 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 5.16 COMBUSTION PRODUCTS Constituents resulting from the combustion of a fuel with the oxygen of the air, including the inerts, but excl

41、uding excess air. 5.17 CONDENSATE The liquid which separates from a gas, including ue gases, due to a reduction in temperature. 5.18 CONTROL A device designed to regulate the fuel, air, water, or electrical supply to the controlled equipment. It may be automatic, semiautomatic, or manual. 5.19 CONTR

42、OL, LIMIT An automatic safety control, responsive to changes in liquid level, pressure, or temperature, for limiting the operation of the controlled equipment. 5.20 CONTROL, OPERATING A control other than a safety control or interlock, to start or regulate burner ring according to load demand and to

43、 stop or regulate re on satisfaction of demand or upon reaching normal temperature or pressure in the device being red. Operating controls may also actuate auxiliary equipment. 5.21 CONTROL, PRIMARY SAFETY An automatic control that monitors the operation of a gas-red or an oil-red burner. It normall

44、y consists of the following sections that may be integrated into a common unit or may be separate units, interconnected by wiring: a) A device that programs the burner through start-up and shutdown operations in response to signals from regulating, limiting, and monitoring devices. It also provides

45、the necessary timings, in proper sequence, for purging, pilot ame ignition, main ame ignition, and in case of ignition or ame failure, for safety shutdown (lockout). b) A device that is responsive to ame properties. It monitors the ame at the point of ame supervision and transmits a signal to the pr

46、ogramming unit, indicating absence or presence of ame. 5.22 CONTROL, SAFETY Automatic controls, including relays, switches, and other auxiliary equipment used in conjunction therewith to form a safety control system, that is intended to reduce the risk of re, electric shock, or injury to persons dur

47、ing operation of the controlled equipment. 5.23 DAMPER A valve 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. 5.24 DAMPER, AUTOM

48、ATICALLY OPERATED A damper operated by an automatic control. 5.25 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 poten

49、tial of not more than 30 volts alternating- current (42.4 volts peak) or direct current and supplied by: 1) A Class 2 transformer, or by a battery, by a battery and xed impedance, or by a transformer and xed impedance each of which, as a unit is in compliance with what is required for a Class 2 transformer; or FEBRUARY 8, 2017 COMMERCIAL-INDUSTRIAL GAS BURNERS - UL 295 8UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUC