4. DIELECTRICS AND DIELECTRIC PHENOMENA STATIC STRAINS IN HIGH-TENSION CIRCUITS AND THE Percy H. Thomas Discussion, pp. 265-276, by Messrs. C. P. Steinmetz, F. O. Blackwell, H. W. Fisher, Philip Torchio, P. H. Thomas and B. A. Behrend. Results of investigation of needle gap, showing the effect of sharpness on sparking distance; also results of experimental investigation of hightension transmission line, showing the effects of switching with oil and air-break switches. Mathematical study of distribution of potential stress in model as to time and distance measured from time and position of application. ENERGY LOSS IN COMMERCIAL INSULATING MATERIALS WHEN SUBJECTED TO HIGH-POTENTIAL STRAINS Charles Edward Skinner Vol. xix-1902, pp. 1047-1062 Experimental study of energy losses in dielectrics, showing the effects of variation in voltage, temperature, moisture and frequency. The exact nature of the dielectric not given. Test of energy losses in 5,000-kilowatt engine type alternator of Manhattan Railway Company. Discussion (including that of paper by Percy H. Thomas on "The Function of Shunt and Series Resistance in Lightning Arresters," and paper by Miles Walker on "Electrostatic Wattmeter in Commercial Measurements"), pp. 1063-1073, by Messrs. Edw. L. Nichols, Chas. F. Hopewell, Chas. E. Skinner, W. S. Andrews, F. A. C. Perrine, Elihu Thompson, William Maver, Jr., P. B. Woodworth, C. P. Steinmetz and P. H. Thomas. Observed dielectric strength of mica under oil. Electrolytic conduction in cable insulation. Effect of moisture on dielectric strength of oil. General remarks on lightning arresters. SOME RECOMMENDATIONS CONCERNING ELECTRICAL AND MECHANICAL SPECIFICATIONS OF TROLLEY INSULATORS Samuel Sheldon & John D. Keiley Vol. xxii-1903, pp. 231-239 Description of methods and results of testing strain insulators for tensile strength, breakdown e. m. f., insulation resistance and determination of maximum working temperature for round top trolley suspension insulators. Specifications for various forms of insulators for overhead trolley construction. Discussion, pp. 240-242, by Messrs. Joseph Sachs, Ralph D. Mershon and Samuel Sheldon. Recommendations for standard railway insulator specifications. Alternating current vs direct current for testing insulators for use on direct current circuits. THE TESTING OF ELECTRICAL APPARATUS FOR DIELECTRIC STRENGTH P. H. Thomas Vol. xxii-1903, pp. 353-360 Brief discussion of the difficulties and dangers of testing dielectrics, followed by a list of precautions and general recommendations for making such tests. Discussion, pp. 361-371, by Messrs. L. A. Hawkins, M. H. Gerry, Jr., H. G. Stott, J. S. Peck, P. M. Lincoln, Gano S. Dunn, P. H. Thomas, W. L. Waters, C. E. Skinner, Ralph D. Mershon, A. S. Langsdorf, Henry Pikler, Louis Bell and P. G. Gossler. General discussion of dielectric testing; methods of voltage application and measurement; duration of test; effect of fatigue; choice of value of test voltage, etc. Wave distortion due to resistor in series with transformer. Experience with overhead grounded wire. Henry W. Fisher ELECTRIC CABLES FOR HIGH VOLTAGE SERVICE Vol. xxii-1903, pp. 417-420 Brief discussion of requirements to be met in the manufacture, installation and operation of rubber and paper insulated cables. Discussion, incorporated with that of paper by H. G. Stott on "The Use of Automatic Means for Disconnecting Disabled Apparatus." THE CONDUCTIVITY OF THE ATMOSPHERE AT HIGH VOLTAGES · Harris J. Ryan Vol. xxiii-1904, pp. 101-134 Analytical discussion of corona phenomena, reviewing previous experiments of the author and others, followed by account of experimental investigation of corona losses in the laboratory with a cathode tube wave tracer, showing effects of conductor dimensions and atmospheric conditions upon critical voltage, all of which are expressed in equation for critical e. m. f. Discussion, pp. 135-145 and 168-170, by Messrs. C. F. Scott, Samuel Sheldon, Harold B. Smith, P. H. Thomas, Harris J. Ryan, P. M. Lincoln, G. T. Hanchett, Elihu Thomson, Ralph D. Mershon, S. M. Kintner, H. W. Fisher, W. A. Blanck and C. E. Freeman. General remarks on losses to atmosphere at high e. m. f's., with special reference to the critical e. m. f. and the factors which affect it. Difficulties in measuring very high e. m. f's. TERMINALS AND BUSHINGS FOR HIGH-PRESSURE TRANSFORMERS Walter S. Moody Vol. xxiii-1904, pp. 225-230 Location, arrangement and insulation of transformer terminals. Discussion, pp. 23-235, by Messrs. Ralph D. Mershon, C. E. Skinner, Irving A. Taylor, N. M. Snyder, A. C. Pratt. General remarks on transformer terminals and terminal bushings. Weak spots in construction of transformer terminals, taps and bushings. Bushing treated as a condenser. DATA RELATING TO ELECTRIC CONDUCTORS AND CABLES H. W. Fisher Vol. xxiv-1905, pp. 397-414 Experimental study of the safe current-carrying capacity of insulated wires and cables. Effect of steel strands on cable impedance and method of overcoming it. Table of reactances for different sizes of wire and cables at different spacings. Tests of variation of insulation resistance and electrostatic capacity with temperature and of the heating of cables in ducts. Discussion, pp. 415-419, by Messrs. H. G. Stott, C. W. Rice, C. O. Mailloux, Charles P. Steinmetz and H. W. Fisher. Conditions under which high-reactance cable is desirable. John Langan STANDARDIZING RUBBER-COVERED WIRES AND CABLES Vol. xxv-1906 pp. 191-204 Protest against potential test as a criterion of insulation. Characteristics and properties of different grades of rubber, with instructions for easily determining the quality of rubber insulation. Suggested specifications for rubber-covered wires. Discussion, incorporated with paper by Wallace S. Clark on "Comments on Present Underground Cable Practice." COMMENTS ON PRESENT UNDERGROUND CABLE PRACTICE Wallace S. Clark Vol. xxv-1906, pp. 205-213 Notes on electrolysis troubles with the low-tension cables. Effect of grounding sheath. Properties of insulation, tests of durability and record of operation of 11,000-volt 25-cycle rubber-covered leaded cables. Specifications of Rubber-Covered Wire Engineers' Association for 30 per cent. rubber compound. Discussion (included with paper by John Langan on "Standardizing Rubber-Covered Wires and Cables"), pp. 214-239, by Messrs. H. W. Fisher, H. G. Stott, Wallace D. Clark, John Langan, Philip Torchio, A. E. Kennelly, E. W. Stevenson, Townsend Wolcott, Durand Woodman, William McClellan, J. B. Taylor, C. F. Scott, S. S. Wheeler, Dugald C. Jackson, F. R. Cutcheon, J. H. Schumacher, H. J. Gille, John Pearson and E. H. Scofield. General discussion of the requirements of rubber insulation and the methods of fixing and testing them. Results of tests on rubber insulated wires showing effect of percentage of Para on the performance characteristics under different conditions and indicating the method of determining the quality of insulation. THE HEATING OF COPPER WIRES BY ELECTRIC CURRENTS A. E. Kennelly & E. R. Shepard Vol. xxvi-1907, pp. 969-995 Experimental investigation of the heating of wires under various conditions of cooling by thermal conduction-through insulation, sand, water, and molding. Much data on thermal resistivity of insulation materials, wood and various soils. Graphical diagrams of the current carrying capacity of different sized wires under the various conditions. No discussion. POWER-FACTOR, ALTERNATING-CURRENT INDUCTIVE CAPACITY, CHEMICAL AND Henry W. Fisher Discussion, pp. 1021-1025, by Messrs. Henry W. Fisher, Charles P. Steinmetz, E. W. Stevenson and Henry G. Stott. General remarks on dielectric properties of cables. HIGH-VOLTAGE MEASUREMENTS AT NIAGARA Ralph D. Mershon Vol. xxvii-1908, pp. 845-903 Detailed account of tests on high-tension lines, covering the losses of line to atmosphere by corona, leakage over insulators, etc., with various spacings, conductor diameters, frequencies and atmospheric conditions; also the effect of the various factors in the occurrence of the critical voltage. Most data is presented in graphic form. In conclusion there are 22 items that have a distinct bearing upon the operation of very hightension lines, and which have been deduced from the results of these tests and those made at Telluride and by Professor Ryan. Discussion, pp. 904-929, by Messrs. Henry Doherty, Elihu Thomson, Samuel Sheldon, Henry Floy, Chas. P. Steinmetz, Percy H. Thomas, P. M. Lincoln, Carl Hering, Chas. F. Scott, A. E. Kennelly, W. I,. Waters and N. M. Snyder. General discussion of line and insulator losses at high tension. Defini tion of critical point and explanation of physical meaning of relation between atmospheric losses and vapor product. Analysis of insulator losses. C. E. Skinner THE TESTING OF HIGH-VOLTAGE LINE INSULATORS Vol. xxvii-1908, pp. 945-951 Proposed specifications for routine and design testing of high-tension line insulators. Discussion, pp. 952-958, by Messrs. Percy H. Thomas, Ralph D. Mershon, Clayton H. Sharp, E. M. Hewlett, Chas. P. Steinmetz, C. E. Skinner and N. J. Neall. General remarks on insulator test specifications, with special reference to methods of making the rain test. CONDENSER TYPE OF INSULATION FOR HIGH-TENSION TERMINALS A. B. Reynders Discussion (including that of K. C. Randall's paper on "High-Tension Transformers and Protective and Controlling Apparatus for Outdoor Installation"), pp. 221-268, by Messrs. W. S. Moody, Percy H. Thomas, David B. Rushmore, Paul M. Lincoln, E. M. Hewlett, S. Piek, Guido Semenza, A. E. Kennelly, J. S. Peck, Ralph D. Mershon, W. S. Franklin, N. J. Neall, G. Faccioli, C. L. de Muralt, V. D. Moody, M. W. Franklin, K. C. Reynders, Ralph W. Pope, F. G. Baum, O. S. Lyford, Jr., Carl Schwartz, J B. Whitehead, John J. Frank, W. L. Waters, L. L. Perry, J. N. Kelman, August H. Kruesi and D. Kos. General discussion of the advisability of using outdoor transformer and switching stations. Experience with outdoor high-tension apparatus. Theory and calculation of condenser type bushings. Construction of oil and asphalt filled insulating bushings. CORONA PHENOMENA IN AIR AND OIL AND THEIR RELATION TO W. S. Moody and G. Faccioli Vol. xxviii-1909, pp. 769-798 Theoretical and experimental investigation of corona formation in apparatus of limited dimensions in air and in oil, showing the effect of character of surface, insulating masses, conductor masses, dimensions of conductor, etc. Discussion, pp. 799-804, by Messrs. John B. Whitehead, J. C. Lincoln, Ralph D. Mershon, S. B. Charters, Jr., W. S. Moody and Harris J. Ryan. Dielectric strength and conducting character of air. Mechanical strains due to corona under oil. Description of Ryan's corona voltmeter. THE APPLICATION OF PORCELAIN TO STRAIN INSULATORS Vol. xxix-1910, pp. 967-974 W. H. Kempton Brief account of tests on several different types of strain insulators, giving the utlimate shearing, tensile and compressive stresses. Discussion, incorporated with that of paper by W. N. Smith on "Electric Railway Catenary Trolley Construction." |
