Improvements in or relating to apparatus for the localization of oil leakages in the lead sheaths of oil-filled electric cables

摘要

369,119. Locating leakages in oilfilled cables. SOC. ITALIANA PIRELLI, 21, Via Fabio Filzi, Milan, Italy. July 22, 1931, No. 20983. Convention date, April 15. [Class 99 (ii).] A leakage of oil through a hole in the lead sheath of one of three parallel cables 1, 2, 3 constituting a line is located by connecting the leaky cable 1 say to one of the sound cables 2 by a connection m at the cable joints A1, A11 respectively, and then connecting oil reservoirs S1, S11 to the other ends of the said cables at the joints A1o, A11o. The position of the leak P is determined by maintaining an equal level of oil in the two reservoirs, noting the quantities Q1, Q2 flowing from each in a definite time, and then substituting in the formula where L, x respectively are the lengths of the two cables and the distance of the leak from the joint A1. Variations in the volume of oil in the reservoirs due to variations in temperature during testing are compensated for by connecting a reservoir S111 to the third cable 3. Several devices are described for maintaining a constant level of oil in the reservoirs. Specifications 255,033 and 268,27], [both in Class 38 (i), Electric couplings &c.], are referred to.