1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 378 Draft EquipmentUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION O
2、R DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Draft Equipment, UL 378 Fourth Edition, Dated October 27, 2006 Summary of Topics This revision to UL 378 is being issued to remove the reference to the withdrawal date of UL 873 and to address universal upkeep of UL Standards for S
3、afety. 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 in requirements are marked with a vertical line in the margin
4、 and are followed by an effective date note indicating the date of publication or the date on which the changed requirement becomes effective. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, electronic, mechan
5、ical 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 limited to, the implied warranties of merchantability or tness for any purpose. In no event will UL be liable for an
6、y 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 use this Standard, even if UL or an authorized UL representative has been advised of the possibility of such dama
7、ge. In no event shall ULs liability for any damage ever exceed the price paid for this Standard, regardless of the form of the claim. Users of the electronic versions of ULs Standards for Safety agree to defend, indemnify, and hold UL harmless from and against any loss, expense, liability, damage, c
8、laim, or judgment (including reasonable attorneys fees) resulting from any error or deviation introduced while purchaser is storing an electronic Standard on the purchasers computer system. The requirements in this Standard are now in effect, except for those paragraphs, sections, tables, gures, and
9、/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 Standard, and are preceded by a SUPERSEDED REQUIREMENTS notice. SE
10、PTEMBER 17, 2013 UL 378 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL SEPTEMBER 17, 2013 UL 378 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL OCTOBER 2
11、7, 2006 (Title Page Reprinted: September 17, 2013) 1 UL 378 Standard for Draft Equipment First Edition July, 1957 Second Edition April, 1973 Third Edition June, 1993 Fourth Edition October 27, 2006 This UL Standard for Safety consists of the Fourth Edition including revisions through September 17, 2
12、013. The Department of Defense (DoD) has adopted UL 378 on June 20, 1994. The publication of revised pages or a new edition of this Standard will not invalidate the DoD adoption. Comments or proposals for revisions on any part of the Standard may be submitted to UL at any time. Proposals should be s
13、ubmitted via a Proposal Request in ULs On-Line Collaborative Standards Development System (CSDS) 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 right
14、s regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2013 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL OCTOBER 27, 2006 DRAFT EQUIPMENT - UL 378 2 No Text on This PageUL C
15、OPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .4 2 Components 5 CONSTRUCTION 3 General 5 4 Assembly 6 5 Materials .7 6 Springs 7 7 Diaphragms 7 8 General 7 9 Uninsulated Live Parts .8 10 Motors 9 11 Wiring Methods
16、 .10 12 Spacings 12 PERFORMANCE 13 General 12 14 Installation for Temperature Tests 13 15 Temperature Measurement 14 16 Normal Temperature Test 16 17 Abnormal Temperature Test .19 18 Stalled Motor Test 19 19 Fan Motor Operation Test .19 20 Draft Regulators Operation Test 20 21 Automatic Damper Contr
17、ols Operation Test 23 22 10-Day Moist Ammonia Air Stress Cracking Test .23 MANUFACTURING AND PRODUCTION TESTS 23 General 24 MARKING 24 General 24 OCTOBER 27, 2006 DRAFT EQUIPMENT - UL 378 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTR
18、ODUCTION 1 Scope 1.1 These requirements apply to the design and construction of draft equipment intended to assist in maintaining the desired combustion chamber draft in heating appliances. Draft equipment classications include draft regulators, automatic damper controls, and draft fans for inducing
19、 draft. 1.2 Draft regulators are intended for installation in the breeching or ue pipe of heating appliances where a constant draft is desired, but function to regulate draft only when the draft in the chimney is greater than the draft for which the automatic damper is adjusted. 1.3 Draft regulators
20、 intended for use with liquid, combination gas-liquid, or solid fuel-burning equipment, which provide means for the relief of positive pressures in the ue pipe into the adjoining space, provide arrangements for the installer to interlock the assembly with automatic fuel-burning equipment in a manner
21、 which will prevent the continued operation of the fuel-burning equipment for more than a brief period of time under conditions of sustained positive draft. 1.4 Draft regulators which provide means for the relief of positive pressures in the ue pipe into the adjoining space and which do not provide
22、means for interlock as described above are intended for use only with commercial-industrial gas-burning equipment not ordinarily equipped with a draft hood. 1.5 Automatic damper controls are designed to automatically regulate the position of dampers installed in the ue pipe or combustion air intake
23、of heating appliances to regulate available draft or combustion air supply to desired values. 1.6 Draft fans are intended for installation in the ue pipe or breeching adjacent to heating appliances or to chimneys to induce or create a draft to supplement the natural draft created by the chimney. Fan
24、 units may include automatic dampers or automatic damper controls. 1.7 Requirements for the installation and use of draft equipment are included in the Standards of the National Fire Protection Association for the Installation of Oil-Burning Equipment, NFPA No. 31, and for the National Fuel Gas Code
25、, NFPA No. 54. 1.8 A product that contains features, characteristics, components, materials, or systems new or different from those in use when the standard was developed, and that involves a risk of re, electric shock, or injury to persons, shall be evaluated using the appropriate additional compon
26、ent and end-product requirements as determined necessary to maintain the level of safety for the user of the product as originally anticipated by the intent of this standard. OCTOBER 27, 2006 DRAFT EQUIPMENT - UL 378 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WI
27、THOUT PERMISSION FROM UL 2 Components 2.1 Components of draft equipment, such as manual or electrically operated valves, etc, electrical components and materials such as attachment plugs, industrial control equipment, switches, transformers, wires, etc., shall comply with the requirements for such c
28、omponents, except that such requirements may be modied if appropriate for the particular application. CONSTRUCTION 3 General 3.1 A draft regulator intended for use with liquid, combination gas-liquid, or solid fuel-burning appliances, shall provide means for the relief of positive pressures in the u
29、e pipe into the adjoining space, shall be equipped with a switch or other interlocking arrangement which can be practically employed by the installer to prevent continued operation of the fuel-burning equipment under conditions of sustained positive draft in excess of 0.02 inch water column. Such sw
30、itch or interlocking arrangement shall function to stop the fuel-burning equipment under the above condition in not less than 5 seconds and not more than 10 seconds under situations providing normal ambient room temperatures and normal voltages impressed on any electrical parts. The arrangement shal
31、l function in not less than 3 seconds and not more than 15 seconds when voltages of 110 percent and 85 percent of normal are impressed on electrical parts and when ambient temperatures are maintained at 57.5C (135F), simultaneously. 3.2 A draft regulator intended for use with liquid, combination gas
32、-liquid, or solid fuel-burning equipment and not provided with means for interlock as described in 3.1, shall substantially prevent the relief of ue gases from the ue pipe when under positive pressure into an adjoining space. 3.3 A draft regulator providing means for the relief of positive pressures
33、 in the ue pipe into the adjoining space and not equipped with a switch or other interlocking arrangement as described in 3.1 and 3.2 shall be for use only with gas-red commercial-industrial fuel-burning equipment and be so marked on its assembly. 3.4 Automatic damper controls intended to regulate t
34、he position of dampers installed in the ue pipe shall provide adjustable means for connection to such dampers. 3.5 An automatic damper control shall be designed to maintain a safe damper opening at all times and be arranged to prevent starting of the heating equipment until such damper is opened to
35、a safe position. 3.6 Interlocks provided for compliance with 3.1 and 3.5 shall be considered as a safety control. OCTOBER 27, 2006 DRAFT EQUIPMENT - UL 378 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 4 Assembly 4.1 A draft equipment ass
36、embly shall include all the components necessary for its normal function. 4.2 The construction of draft equipment shall be such that parts can be readily reassembled in a proper manner after being dismantled to the extent needed for normal care. 4.3 The assembly of a diaphragm-operated mechanism sha
37、ll be such that positive motion of the mechanism will follow as a result of diaphragm movements. 4.4 All metal parts of a diaphragm-type mechanism coming in contact with the diaphragm shall have no sharp edges, burrs, projections, etc., which might chafe or abrade the diaphragm. 4.5 Convenient means
38、 shall be provided for the purpose of making any necessary eld adjustment. 4.6 Screws or bolts used to attach parts which are detached for normal care or servicing of the equipment shall be capable of holding, upon the application of the torques indicated in Table 4.1 after removal and replacement.
39、Table 4.1 Maximum torque requirements for screws Screw size Torque, pound-inches No. 8 20 No. 10 25 1/4 inch 100 5/16 inch 200 3/8 inch 350 7/16 inch 550 1/2 inch 800 9/16 inch 1200 4.7 The device shall incorporate adequate provisions for support or attachment to a ue pipe, foundation, or wall surfa
40、ce independent of piping, tubing, or conduit that may be connected thereto. OCTOBER 27, 2006 DRAFT EQUIPMENT - UL 378 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 5 Materials 5.1 Draft equipment parts for conveying or in direct contact w
41、ith ue gases shall be made of noncombustible corrosion resistant materials. Such parts shall be made of material having durability and resistance to corrosion, re, and heat equivalent to suitable stainless steel, cast-iron, or hot-rolled steel. 5.2 The minimum thickness, with a minus tolerance of ze
42、ro, of sheet metal, including coatings where shown, for compliance with 5.1 as follows: Stainless steel 0.012 inch Aluminum-coated steel 0.053 inch Hot-rolled steel 0.053 inch 5.3 A part made of drawn brass or machined from brass rod shall be capable of withstanding, without cracking, a mercurous-ni
43、trate test for copper and copper alloys. See 22.1 22.4. 6 Springs 6.1 A spring shall be protected against abrasion and corrosion. 6.2 The design and application of a spring employed in a safety mechanism shall be such that it is not likely to fail because of corrosion, fatigue, overstress, wear, etc
44、., if failure of the spring will allow unsafe operation of the device. 7 Diaphragms 7.1 A diaphragm or bellows shall be designed to withstand the conditions of extended service without failure and shall be protected from physical damage. 8 General 8.1 A low-voltage safety control circuit shall be wi
45、red by the manufacturer as required for Class 1 low-voltage circuits. 8.2 Electrical equipment and wire shall be suitable for the particular application. 8.3 Draft equipment shall be constructed so that the enclosure, frame, and similar noncurrent carrying parts of all high-voltage electrical equipm
46、ent are bonded adequately to the means for connecting the metal-clad cable or conduit of the supply circuit. An insulated conductor provided for such purpose shall show a green color with or without one or more yellow stripes. 8.4 Attachment plugs or separable connectors shall not be used in circuit
47、s if the breaking or making of the circuit by such devices may allow unsafe operation of the system served by the draft equipment. 8.5 All electrical circuits of each assembly to which connections are to be made in the eld shall terminate at suitable boxes or enclosures in which connections to the c
48、ircuit can be made. The boxes and enclosures shall permit the proper connection of metal-clad cable or conduit. OCTOBER 27, 2006 DRAFT EQUIPMENT - UL 378 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 8.6 A box or enclosure included as par
49、t of the assembly and in which a branch circuit supplying power to the equipment is to be connected, shall not require that it be moved for normal care of the unit. 8.7 A box or enclosure in which eld-installation conductors are to be connected shall be so located that the temperature of conductors within the box or surfaces of the box likely to be in contact with the conductors will not exceed that specied for Type R wire when the draft equipment is tested in accordance with these requirements. 8.8 The
