From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Test setup and results for determining the electric strength and temperature rise of fibrous insulating materials under A.C. voltage stress.
| Identifier | ExFiles\Box 24\2\ Scan225 | |
| Date | 21th February 1922 guessed | |
| FIBROUS INSULATING MATERIALS. 801 VARIABLE A.C. SUPPLY HIGH RESISTANCE EARTH SHORT C'T'G SWITCH 52 VOLT BATTERY THERMOMETER COLD JUNCTION SPECIMEN 5" X 4 1/2" EUREKA COPPER TINFOIL 4" x 3 1/2" WEIGHT 6.2 lb. THERMO JUNCTION (a)= 1/2" COARSE FELT 4 3/4" x 4 3/4" Fig. 9.—Connections for ascertaining the electric strength when the material is subjected to long applications of voltage. NOTE: a, b, c, d, e & f represent the A.C. voltage stresses applied for the time interval between their respective arrow heads. A.C. VOLTS PER MIL Temperature Rise Leakage Current Temperature Rise °C Leakage Current microamps Time : Hours Fig. 10.—Showing method of expressing the results of the test illustrated in Fig. 9. | ||