1、ANSI Z21.23-2010American National Standard ForGas Appliance ThermostatsCopyright 2010CSA America, Inc.Permission is granted to republish material herein in laws or ordinances, and in regulations, administrative orders, or similar documents issued by public authorities. Those desiring permission for
2、other republication should consult CSA America, Inc., 8501 East Pleasant Valley Road, Cleveland, Ohio 44131.Eleventh Edition - 2010The standards is a revised edition of the former standard forGas Appliance Thermostats, Z21.23-2000 Z21.23a-2003 Z21.23b-2005ApprovedAugust 27, 2010American National Sta
3、ndards Institute, Inc.Standard DeveloperCSA AMERICA INC.8501 East Pleasant Valley RoadCleveland, Ohio 44131Published - October 2010American National Standards InstituteResponsibility of approving American National Standards rests with theAmerican National Standards Institute, Inc.25 West 43rd Street
4、, Fourth FloorNew York, NY10036The American National Standards Institute (ANSI), Inc. is the nationally recognized coordinator of voluntary standards development in the United States through which voluntary organizations, representing virtually every technical discipline and every facet of trade and
5、 commerce, organized labor and consumer interests, establish and improve the some 10,000 national consensus standards currently approved as American National Standards.ANSI provides that the interests of the public may have appropriate participation and representation in standardization activity, an
6、d cooperates with departments and agencies of U.S. Federal, state and local governments in achieving compatibility between government codes and standards and the voluntary standards of industry and commerce.ANSI represents the interests of the United States in international nontreaty organizations s
7、uch as the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). The Institute maintains close ties with regional organizations such as the Pacific Area Standards Congress (PASC) and the Pan American Standards Commission (COPANT). As such, ANSI
8、 coordinates the activities involved in the U.S. participation in these groups.ANSI approval of standards is intended to verify that the principles of openness and due process have been followed in the approval procedure and that a consensus of those directly and materially affected by the standards
9、 has been achieved. ANSI coordination is intended to assist the voluntary system to ensure that national standards needs are identified and met with a set of standards that are without conflict or unnecessary duplication in their requirements.PrefaceThis publication represents a basic standard for s
10、afe operation, substantial and durable construction, and acceptable performance of gas appliance thermostats. It is the result of years of experience in the manufacture, testing, installation, maintenance, inspection and research on gas appliance thermostats designed for the utilization of gas. Ther
11、e are risks of injury to persons inherent in some appliances that, if completely eliminated, would defeat the utility of the appliance. The provisions in this Standard are intended to reduce such risks while retaining the normal function of the appliance.Nothing in this standard is to be considered
12、in any way as indicating a measure of quality beyond compliance with the provisions it contains. It is designed to allow compliance of gas appliance thermostats, the safety construction and performance of which may exceed the various provisions specified herein. In its preparation, recognition has b
13、een given to possibilities of improvement through ingenuity of design. As technical advances take place, revisions may become necessary. When they are believed desirable, recommendations or suggestions should be forwarded to the Chairman of Standards Committee Z21/83, 8501 East Pleasant Valley Road,
14、 Cleveland, Ohio 44131. A proposal form is provided in the back of this document.Safe and satisfactory operation of gas appliance thermostats depends to a great extent upon its proper installation, use and maintenance. It should be installed, as applicable, in accordance with the National Fuel Gas C
15、ode, ANSI Z223.1/NFPA 54; the (U.S.) Manufactured Home Construction and Safety Standard, Title 24 CFR, Part 3280, or when such standard is not applicable, Manufactured Home Installations, ANSI/NCSBCS A225.1 or the Standard for Manufactured Home Installations, Sites, and Communities, ANSI/NFPA 501A,
16、manufacturers installation instructions, and local municipal building codes.Users of this American National Standard are advised that the devices/products/activities within its scope may be subject to regulation at the Federal state or local level. Users are strongly urged to investigate this possib
17、ility through appropriate channels. In the event of a conflict with this standard, the Federal, state or local regulation should be followed.CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute, Inc., req
18、uire that action be taken to reaffirm, revise or withdraw this standard no later than five (5) years from the date of approval. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute, Inc., 25 West 43
19、rd Street, Fourth Floor, New York, N.Y. 10036, (212) 642-4900.EFFECTIVE DATE: An organization using this standard for product evaluation as a part of its certification program will normally establish the date by which all products certified by that organization should comply with this standard.iiHis
20、tory Of The Development Of Standard ForGas Appliance Thermostats(This History is informative and is not part of the standard.)There appears to be no evidence of the existence of construction and performance standards for gas appliance thermostats prior to the preparation of this standard, except for
21、 certain performance provisions in previous American Gas Association standards for domestic gas appliances, such as gas ranges and gas water heaters. These standards were primarily concerned with appliance performance, and thermostats were considered only to the extent of their effect on appliance o
22、peration.In September 1930, a representative of the National Gas Appliance Manufacturers Association appeared before American Standards Association Sectional Committee Z21 requesting recognition of various accessories used on, or in conjunction with, gas appliances. A special committee was appointed
23、 to study this problem which resulted in the formation of the Subcommittee on Listing Requirements for Gas, Pressure and Temperature Control Accessories in May 1931 for the development of standards for various control accessories.At the first meeting of this group in March 1932, the general scope of
24、 its assignment was considered and, since there were a number of distinct types of accessories to be considered, representative subgroups were appointed to draft standards for specific classes of accessories.One of these subgroups was the Subcommittee on Listing Requirements for Thermostats and Ther
25、mostatic Pilots. A draft standard for thermostats was developed by this group and distributed to the industry for review and comment during August 1933. The draft standard was reconsidered in April 1934 in conjunction with the comments received and was adopted with minor revisions. The resultant dra
26、ft standard was adopted by the Z21 Committee at its June 1934 meeting. The first edition of this standard was subsequently approved as American Standard by the American Standards Association in February 1935.An expansion of the standard to cover thermostats used on various gas appliances, including
27、substituting the words “gas appliance thermostats” for the term “water heater, gas range and space heater thermostats” was distributed for review and comment in April 1939. The revisions were adopted by the Z21 Committee, and the second edition of this standard was subsequently approved as American
28、Standard in February 1940.The development of new types of gas appliance thermostats, such as range top burner thermostats and low temperature oven thermostats, and general progress in the development of gas appliance thermostats prompted the subcommittee to prepare extensive revisions to the standar
29、d. Following the procedures outlined above, these revisions were adopted by the Z21 Committee at its March 1961 meeting. This third edition was subsequently approved as American Standard by the American Standards Association, Inc., in October 1961.The increasing use of electric switch type thermosta
30、ts prompted further revisions to the standard to cover this type of thermostats, in addition to integral gas valve type thermostats, and revisions covering thermostats of both types for use in gas refrigerators. These revisions were subsequently adopted by the Z21 Committee at its March, 1963 meetin
31、g. The fourth edition was approved as American Standard by the American Standards Association, Inc., in December 1963.iiiIn August, 1966, the American Standards Association, Inc., was reconstituted as the United States of America Standards Institute which, in October, 1969, was in turn renamed the A
32、merican National Standards Institute, Inc. As a result, the fifth through seventh editions of the gas appliance thermostat standard were approved as American National Standards by the American National Standards Institute, Inc., between 1971 and 1980.Following the procedure outlined above, further r
33、evisions to this standard were developed in line with industry developments. This, the tenth edition of the gas appliance thermostat standard was approved as an American National Standard by the American National Standards Institute, Inc., on August 27, 2010.Previous editions of the gas appliance th
34、ermostat standard, and addenda thereto, approved by ANSI or its predecessor organizations are as follows:Z21.23-1935 Z21.23-1975 Z21.23a-1977 Z21.23b-1978Z21.23-1940 (R1947, 1950, 1953) Z21.23-1980 Z21.23a-1985 Z21.23b-1988Z21.23-1961 Z21.23-1989 Z21.23a-1991 Z21.23b-1993Z21.23-1963 (R1968) Z21.23-1
35、993 Z21.23a-1994 Z21.23b-1997Z21.23-1971 Z21.23a-1971 Z21.23b-1974 Z21.23-2000 Z21.23a-2003 Z21.23b-2005NOTE: This edition incorporates changes to the 2000 edition of Z21.23, and addenda thereto. Changes other than editorial, are denoted by a vertical line in the margin.ivZ21/83 Technical Committee
36、on Performance and Installation of Gas Burning Appliances and Related AccessoriesDARYL L. HOSLER, ChairmanPAUL E. BEACH, Vice ChairmanREPRESENTING AIR CONDITIONING, HEATING AND REFRIGERATION INSTITUTE:Charles W. Adam Allen Kessler Gary J. PotterPaul Beach Norm Mattson Neil Rolph (Alternate)Mark Dies
37、ch Frank MyersREPRESENTING AMERICAN ASSOCIATION OF FAMILY AND CONSUMER SCIENCE:JoAnn EmmelREPRESENTING AMERICAN GAS ASSOCIATION:Jim RanfoneREPRESENTING AMERICAN PUBLIC GAS ASSOCIAITIONMike DeeganREPRESENTING ASSOCIATION OF HOME APPLIANCE MANUFACTURERS:Peter HoekstraREPRESENTING ATMOS ENERGY:Ronnie R
38、ay FrazierREPRESENTING CRANE ENGINEERINGMatthew WilberREPRESENTING BURNER TECHNOLOGY UNLIMITED, INC.:Carl SuchovskyREPRESENTING CRANE ENGINEERING:Matthew WilberREPRESENTING CONSUMER:Hall Virgil Amy SherwinvZ21/83 Technical Committee on Performance and Installation of Gas Burning Appliances and Relat
39、ed Accessories (cont.)REPRESENTING DIRECT ENERGY CORPORATION:Geoff AdkinsonREPRESENTING HEARTH, PATIO AND BARBEQUE ASSOCIATION:Thomas StroudREPRESENTING INDIVIDUAL MEMBERS:Daryl L. Hosler Issac SargunamREPRESENTING NATIONAL GRID:Edward J. AngeloneREPRESENTING NATIONAL ELECTRICAL MANUFACTURERS ASSOCI
40、ATION:Gerard WinstanleyREPRESENTING NATIONAL PROPANE GAS ASSOCIATION:Bruce J. SwiecickiREPRESENTING NORTH AMERICAN ASSOCIATION OF FOOD EQUIPMENT MANUFACTURERS:Charles Souhrada Terry Wiseman (Alternate)REPRESENTING SOUTHERN CALIFORNIA GAS COMPANY:Lance DeLaura Ron Caudle (Alternate)REPRESENTING UNDER
41、WRITERS LABORATORIES:Robert Wozniak Travis Hardin (Alternate)REPRESENTING U.S. CONSUMER PRODUCT SAFETY COMMISSION (Non-voting):Donald W. SwitzerREPRESENTING U.S. DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT:Victor J. FerranteviTechnical Advisory Group On Standards For Automatic Gas ControlsSCOTT J. D
42、ALEY, ChairmanREPRESENTING GAS COMPANIES:Scott J. DaleyGene McPhersonREPRESENTING MANUFACTURERS:Paul E. BeachJohn BieritzKevin CarlisleThomas A. ChodackiRichard CowenDavid DelequilaRobert DunnDavid FallonAlex Gafford (Alternate)Greg FilkovskiJim JollayDon KasprzyPaul KinninghamFlorin LazarKerry Leas
43、onGene McPhersonKen MinklerJim MyersKevin NorbyJoe RoseRobert RothrockJohn SchlachterTom StroudFranklin SwitzerviiContentsPagePart I Construction 1.1 Scope .11.2 General .11.3 Data Furnished By Manufacturer .31.4 Connections .31.5 Mounting .41.6 Bolts, Nuts, Screws And Other Threaded Parts 41.7 Adju
44、stments 41.8 Strength .51.9 Materials .51.10 Temperature Markings 51.11 Resistance To Corrosion 61.12 Assembly 61.13 Electrical .71.14 Instructions .101.15 Marking 11Part II Performance 2.1 General .152.2 Leakage 162.3 Strength And Deformation 172.4 Accuracy Of Temperature Set Point .202.5 Effect Of
45、 High Ambient Temperature On Performance OfThermostats For Top Burners And Griddles .232.6 Capacity .242.7 Valve Opening Characteristics Of Snapacting Thermostats 262.8 Continued Operation 272.9 Dielectric Strength 302.10 Maximum Allowable Operating Temperatures ForVarious Component Parts Of Electri
46、c Thermostats .312.11 Overload .312.12 Current Input 322.13 Resistance To Permanent Damage At Excessive Supply Pressure 322.14 Exemptions .322.15 Marking Material Adhesion And Legibility .33TablesTable I Minimum Thread Length And Length To Shoulder .34Table II Recommended Dial Temperature Markings .
47、34Table III Calibration Reference Point(s) .35Table IV Minimum Spacings Line Voltage Circuits For Safety Circuits 36Table V Minimum Spacings - Millivoltage Circuits Intended for Access After the Control Manufactured andfor Class 2 Low Voltage Safety Circuits (0-30 Volts) .37Table VI Minimum Spacings
48、 - Isolated Limited Secondary Circuits for Safety Controls 38Table VII .39viiiContents (Continued)PageTable VIII Permissible Temperature Variation From Set Point .40Table IX Loads For Bending Moments Test (kg) 41Table X Torques For Turning Effort Test .41Table XI Number of Cycles for ThermostatTempe
49、rature Selecting Mechanism .41Table XII Maximum Allowable Rise OperatingTemperatures For Various Component Parts 42FiguresFigure 1 Typical Arrangement of Thermostat Capacity Test Apparatus 44Figure 2 Typical R/T curve for a ceramic PTC thermistor .45Figure 3 Typical R/T curve for a NTC thermistor .46EXHIBIT A List Of Reference Standards .47Part III Manufacturing And Production Tests .49Part IV Definitions 51APPENDIX A Preferred Graphic Symbols Of Commonly Used Items, Extracted From ANSI/IEEE Standard 315, Graphic Symbols For Electrical And Electronics Diagrams, And Abbreviations For These
