Portable schering bridge for field tests

Discussion of a paper by C. F. Hill, T. R. Watts, and G. A. Burr published in the January 1934 issue, pages 176–82, and presented for oral discussion at the insulation and protection session of the South West District meeting, Oklahoma City, Okla., April 24, 1935. This paper was also presented at the winter convention, New York, N. Y., January 25, 1934, and other discussion was published in the March 1934 issue, pages 478–81, April 1934 issue, pages 618–22, and September 1934 issue, page 1311. G. W. Gerell (Union Electric Light and Power Co., St. Louis, Mo.): The experience of my company with the power factor testing of bushings is rather limited. In 1933 the 66 and 132 kv transformer and oil switch bushings on Westinghouse equipment at the Cahokia and Venice stations only, were tested by means of the Schering bridge. In the fall of 1934 all bushings on the 66 and 132 kv system were tested. In addition quite a few 33 kv bushings in certain of the a-c distributing substations were included.