Mulhall, V. R.
Engineer, Canadian General Electric Co., Peterborough, Ont.
Pages: 1 Published: Jan 1960
This symposium, the eighth in a series on insulating oils presented over a period of 13 years, fits naturally into the general theme of previous symposia but emphasizes the growing interest in high-voltage cables and reflects the trend towards operating voltages of 300 kv and higher. The theme of this symposium is insulation for high-voltage cables or, more specifically, the composite insulation system of oil-impregnated paper. Of necessity the subject deals with solid as well as liquid materials but with special emphasis on the petroleum-oil component. Thus the previous interest in transformer applications has been expanded to include insulated cables. The need for a symposium on this subject has been apparent for several years in order to direct the interests of the Committee D-27 membership towards the development of test methods and interpretation of test results for these applications and to explore, in greater depth, the needs of the manufacturers and the industrial and utility users of finished cable. Perhaps the main achievement of the symposium was to make the oil technologists more aware of some of the problems which now exist and which may be expected in the future in the application of cable oils, especially with the advent of extra-high voltages. The first two papers are concerned with the traditional oil-impregnated paper-insulation system. It has been predicted that, as operating voltages increase and technology advances, this system will very quickly recede into obsolescence. These two papers present information to refute this statement. Author Wm. A. Del Mar expresses the need for effective cooperation within the industry and suggests the direction in which such cooperation must move to achieve the goal of improved quality at elevated operating voltages. Author R. B. Blodgett, in an extensive review, provides an interpretation of the test methods which in his opinion, are most important for the evaluation of cable oils and correlates in detail the observed properties of oil with the necessary properties of an insulation system suitable for use in a 345-kv cable. The third paper by Messrs. A. M. Gates and R. W. Gillette defines, from the viewpoint of the ultimate user, a presently existing problem associated with the continuing purchase of acceptable cable oils and proposes that complete, self-sufficient continuity specifications must be established. The authors contend that with the present state of knowledge, such an accomplishment is not impossible.
Paper ID: STP46958S