1、 No. 22 July 1952 Standard for AIR SWITCHES, INSULATOR UNITS, and BUS SUPPORTS (Effective July 31, 1952) (Supercedes AIEE No. 221942 and 22A1949) Published by AMERICAN INSTITUTE OF ELECTRICAL ENGINEERS 33 West Thirty-ninth Street, New York 18, N. Y. Development of the Standards of the American Insti
2、tute of Electrical Engineers Recognizing the importance in the development of electrical engineering, of standardiza tion in the electrical field, the AIEE in 1898 appointed a Committee on Standardization, consisting of seven members having qualifications and experience from designing, manufac turin
3、g and operating standpoints. The report of this Committee was accepted at a meeting of the Institute in June 1899. Experience gained in appHcations of the standards and further developments in electric apparatus and methods showed the necessity of revision, and a committee was appointed which after
4、consultation with manufacturing and operating engineers presented the first revised report on Standardization Rules of the AIEE in June 1902. The next revision was undertaken by a committee of ten, which presented its report in May 1906. In September 1906, a Standards Committee of eleven members was
5、 appointed for further revision, and its report was presented in June 1907. The appreciation of the importance and value of standardization resulted in the forma tion of a Standing Committee, with the title of Standards Committee of the AIEE. This became effective in the Constitution of June 1907. T
6、he scope and amount of work necessitated increasing the number of members from time to time until in 1922 there were 37 members divided into a number of subcommittees specializing on various subjects. AIEE Standards published in a single volume as each revision was adopted were generally accepted as
7、 standards of the electrical industry of the United States since the adoption of the first report in 1899. Subsequent reports on standards were made and pub lished, in some cases in several editions. The dates of adoption by the Board of Directors of such reports are as follows: June 20, 1902; June
8、21, 1907; June 27, 1912; July 10, 1914; June 30, 1915; June 28, 1916; November 8, 1918; October 8, 1920, and June 29, 1922. On June 29, 1922, in view of the increasing complexity of the work, a reorganization of the Standards Committee was effected, and a working organization established which pro v
9、ided for an increase in standardization work and for the appointment on Working Commit tees of the Standards Committee of non-Institute members. The present plan under which the Institute Standards are being issued involves the sepa ration of the complete body of standards into more than forty secti
10、ons, each published as a separate pamphlet and dealing with a specific subject. Each section of the standards has been formulated either by a subcommittee of the Standards Committee which was made as rep resentative as possible for the work in hand, by an AIEE Technical Committee or subcom mittee, o
11、r by a Sectional Committee organized according to the procedure of the American Standards Association. The division of the standards into a number of separate publications simplifies the process of keeping the standards revised to conform with the latest develop ment and enables those interested in
12、a particular field to obtain in concise form the material relating to that field. In framing the Institute Standards the chief purpose has been to define terms and conditions which characterize the rating and behavior of electric machinery and apparatus, with special reference to the conditions of a
13、cceptance tests. The AIEE Standards Committee takes this occasion to draw attention to the value of suggestions based upon experience gained in the application of the standards to general practice. Any suggestions looking toward improvements in the standards will be welcomed for the guidance of the
14、Committee in preparation of future editions, and should be communicated to the Secretary of the AIEE Standards Committee, 33 West 39th Street, New York 18, N. Y. TABLE OF CONTENTS Scope 5 Service Conditions S Definitions 6 GeneralProperties and Characteristics 6 Classification 7 Construction Arrange
15、ments and Parts 7 Classes of Operation 9 Rating 10 Classification of Insulation Materials 11 Tests 2 General 1Temperature Rise Tests 13 Interrupting Tests on Air Interrupter Switches 13 Nameplate Markings 14 Appendix A Recommended Methods for Determining the Rms Value of a Sinusoidal Current Wave 15
16、 Appendix Simplified Calculation of Fault Currents 19 INTRODUCTION The AIEE standards on certain related devices have been grouped into this one standard. This saves duplication and serves to set off important differences when they exist. Essential data from Reports and Standards of AIEE, as well as
17、 definitions from the American Standard Definitions of Electrical Terms, C42 have been incorporated for ready reference. These terms are fol lowed by their C42 designating number in parentheses. Specific defini tions have also been included. If there is need for further clarification, reference shou
18、ld be made to the following: AIEE Standards Manual AIEE 1 Introduction to AIEE Standards General Principles Upon Which Temperature Limits are Based in The Rating of Electric Machines and Apparatus. AIEE IB Report on Guiding Principles for the Specification of Service Conditions in Electrical Standar
19、ds. AIEE 3 Guiding Principles for the Selection of Reference Values for Electrical Standards. AIEE 4 Measurement of Test Voltage in Dielectric Tests. AIEE 29 Wet Tests ASA C29.1 - Insulator Tests ASA C42 Definitions of Electrical Terms EEI-NEMA Report on Preferred Voltage Ratings There are other com
20、mittees of the AIEE working on various reports and standardization problems such as impulse ratings, simplified calcu lation of short-circuit currents, definitions, etc. When they are_ com pleted and approved some changes in this standard may be advisable. ACKNOWLEDGMENT The Institute wishes to ackn
21、owledge its indebtedness to those who have so freely given their time and knowledge, and have conducted experimental work on which many of the AIEE Standards are based. The work of preparing this standard was carried out by members of the Subcommittee on Switches, Fuses and Insulators of the AIEE Co
22、mmittee on Switchgear. The members of the subcommittee are: K. J. Falck, Chairman R. H. Amundson T. E. Curtis H. W. Graybill G. L. Hill J. B. Owens A. H. Powell J. C. Woods C. P. Zimmerman Standard of the American Institute of Electrical Engineers AIR SWITCHES, INSULATOR UNITS, AND BUS SUPPORTS SCOP
23、E This standard applies to the following types of devices designed for operation above 600 volts whether for indoor or outdoor service. (a) Air switches such as disconnecting, grounding, etc., for manual or automatic oper ation. (See 22-73, 75 and 79) (b) Air interrupter switches. (See 22-79.3) (c)
24、Insulator units and bus supports. (See 22-119 and 71) SERVICE CONDITIONS 22-1 Usual Temperature and Altitude Service Condi tionsEquipment conforming to this standard shall be suitable for operation at its standard rating, provided that: (a) The temperature of the cooling air (am bient temperature) d
25、oes not exceed 40C if the equipment has copper-to-copper contacts or equivalent. (b) The temperature of the cooling air (am bient temperature) does not exceed 55C if the equipment has all contacts silver surfaced or equivalent, and in addition has all conducting joints, including terminal connection
26、s, either (1) Separately held mechanically, and either soldered or silver surfaced, or (2) Brazed, welded or silver soldered and provided that such operation does not result in temperatures in excess of 90C for class O, lose for class A or 130C for class insula tions. (c) The altitude does not excee
27、d 3300 feet (1000 meters). 22-2 Unusual Temperature and Altitude Service ConditionsThe application of equipment at higher ambient temperatures or at higher alti tudes than specified in Usml Service Conditions shall be considered as special. Standard equipment may be applied at higher ambient tempera
28、tures or at higher altitudes than specified, but its performance may be affected and special consideration should be given to these applications. 22-3 Other Conditions Which May Affect Design and ApplicationWhere other unusual conditions exist they should be brought to the attention of those respons
29、ible for the design and appli cation of the equipment. Examples of such conditions are: (a) Damaging fumes or vapors, excessive or abrasive dust, explosive mixtures or dust or gases, steam, salt spray, excessive moisture or dripping water, etc. (b) Abnormal vibration, shocks, or tilting. (c) Excessi
30、vely high or low temperatures. (d) Unusual transportation or storage con ditions. (e) Unusual space limitations. (f) Unusual operating duty, frequency of operation, difficulty of maintenance, poor wave form, unbalanced voltage, special insulation re quirements, etc. 22-4 Applications at Altitudes Gr
31、eater Than 3300 Feet (1000 Meters)Equipment that depends on air for its insulating and cooling medium will have a higher temperature rise and a lower dielectric strength when operated at altitudes above 3300 feet. Dielectric strength and current ratings should be multiplied by factors shown in Table
32、s la and lb. Equipment designed for standard tempera ture rise may be used at its normal current rating without exceeding ultimate standard temperature limits provided that the ambient temperature does not exceed the ambient al lowed in paragraph 22-1 multiplied by the factor shown in Table Ic. TABL
33、E I ALTITUDE CORRECTION Altitude Correction Factor Altitude to be Applied To b c Dielectric Current Ambient Feet Meters Strength Rating Temperatur 3300 lOOO 1.00 1.00 1.00 4000 1200 0.98 0.995 0.992 5000 1500 0.95 0.99 0,980 6000 1800 0.92 0.985 0.968 7000 2100 0.89 0.98 0.956 80O0 2400 0.86 0.97 0.
34、944 9000 2700 0.83 0.96S 0.932 10000 3000 0.80 0.96 0.920 12000 3600 0.75 0.95 0,896 14000 4200 0.70 0.935 0.872 16000 4800 0.65 0.92S 0.848 18000 5400 0.61 0.91 0.824 20000 6000 0.56 0.90 0.80O If the derating as determined from the table is seri ous, equipment of a suitably higher rating should be
35、 chosen to meet requirements after derating factors have been applied. The correction factors in Table I columns b and c are not to be applied at the same time. DEFINITIONS Definitions as given herein apply specifically to the apparatus treated in this standard. These and other standard definitions
36、may be found in the American Standard Definitions of Electrical Terms, C42. The numbers in parentheses following many of the defi nitions are the C42 designating numbers. General 22-50 Air (used as a prefix)The prefix air ap plied to a device indicates one in which air is the insulating medium betwe
37、en contacts in the open position. (95.90.005 modified) 22-51 Proof (used as a sufBx)Apparatus is desig nated as splashproof, dustproof, etc., when so constructed, protected or treated that its suc cessful operation is not interfered with when subjected to the specified material or condition. (95.90.
38、015) 22-52 Tight (used as a suffix)Apparatus is desig nated as watertight, dust-tight, etc., when so constructed that the enclosing case will exclude the specified material. (95.90.025) 22-53 Resistant (used as a suffix)Apparatus is designated as moisture-resistant, fume-resistant, etc., when so con
39、structed, protected or treated that it will not be injured readily when subjected to the specified material (95.90.020) 22-54 Outdoor (used as a prefix)The prefix out door, applied to a device, indicates that the device has been designed for outdoor service. (95.90.192 modified) 22-55 Indoor (used a
40、s a prefix)The prefix in door, applied to a device, indicates that the device has been designed for indoor service. (95.90.190 modified) Properties and Characteristics 22-56 Gasproof ApparatusGasproof apparatus is apparatus so constructed or protected that the specified gas will not interfere with i
41、ts success ful operation. (95.90.105) 22-57 Gastght ApparatusGastight apparatus is ap paratus so constructed that the specified gas will not enter the enclosing case under specified conditions of pressure. (95.90.110) 22-58 Fume-Resistant ApparatusFume-resistant apparatus is apparatus so constructed
42、 that it will not be injured readily by the specified fumes. (95.90.115) 22-59 Dustproof ApparatusDustproof apparatus is apparatus so constructed or protected that the accumulation of dust will not interfere with its successful operation. (95.90.125) 22-60 Dust-Tight ApparatusDtist-tight apparatus i
43、s apparatus so constructed that the dust will not enter the enclosing case. (95.90.130) 22-61 Moistiu-e-Resistant ApparatusMoisture-resis tant apparatus is apparatus so constructed or treated that it will not be injured readily by a moist atmosphere. Such apparatus shall be capable of operating in a
44、 very humid atmos phere, such as that found in mines, evaporating rooms, etc. (95.90.140 modified) 22-62 Drip-Proof ApparatusDrip-proof apparatus is apparatus so constructed or protected that its successful operation is not interfered with when subjected to falling moisture or dirt. (95.90.150) 22-6
45、3 Driptight ApparatusDriptight apparatus is apparatus so protected as to exclude falling moisture or dirt. Driptight apparatus may be semi-enclosed apparatus if it is provided with suitable protection integral with the apparatus, or so enclosed as to exclude effectively falling solid or liquid mater
46、ial. (95.90.155 modified) 22-64 Splashproof ApparatusSplashproof appara tus is apparatus so constructed and protected that external splashing will not interfere with its successful operation. (95.90.160) 22-65 Watertight ApparatusWatertight apparatus is apparatus so constructed that a stream of wate
47、r from a hose (not less than 1 inch in dia meter) under a head of about 35 feet and from a distance of about 10 feet can be played on the apparatus for several minutes without leak age. 22-66 Submersible ApparatusSubmersible appara tus is apparatus so constructed that it will operate successfully wh
48、en submerged in water under specified conditions of pressure and time. (95.90.195) 22-67 Weatherproof ApparatusWeatherproof ap paratus is apparatus so constructed or protected that exposure to the weather will not interfere with its successful operation. (95.90.185) 22-68 Sleetproof (Glazeproof) App
49、aratusSleetproof apparatus is apparatus so constructed or pro-protected that the accumulation of sleet will not interfere with its successful operation. (95.90.170) 22-69 Explosionproof ApparatusExplosionproof apparatus is apparatus so constructed that ex plosion of gas within the casing will not injure it or ignite flammable gas outside it. (9S.90.23S modified) Miscellaneous Terms 22-70 Ambient TemperatureAmbient temperature is the temperature of the surrounding cooling medium, such as gas or liquid, which comes in t
