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Conference proceedings front matter may contain various advertisements, welcome messages, committee or program information, and other miscellaneous conference information. This may in some cases also include the cover art, table of contents, copyright statements, title-page or half title-pages, blank pages, venue maps or other general information relating to the conference that was part of the original...
The recent large increase in the number of new wire enamels, with the attendant emphasis on improvement in some particular wire property, necessitates refocusing our attention on the test methods used to obtain these values. Many of these are time honored tests and it is sometimes taken for granted that they will give meaningful values. This results in a tendency to put a number, or a small range,...
Transformer insulation is a broad subject involving many types of materials and numerous methods of test. These materials can be combined in many ways in different designs to operate under various environmental conditions. In addition, insulating materials are called upon to help meet the thermal and mechanical requirements of a transformer as well as the dielectric requirements.
Dry type transformers arc transformers in which the dielectric medium is atmospheric air or nitrogen. Some are ventilated or free breathing while others are hermetically sealed. In both kinds the principal dielectric medium-air or nitrogen — has a dielectric constant of unity while the available insulation materials have dielectric constants considerably greater. This presents a relatively perplexing...
Amid the highly technical papers presented at a conference such as this, it has been suggested that it might be well if there were a few comments from a representative of those who are the ultimate beneficiaries of these developments, the end-users. While no one end-user can fully represent all of the others, this paper will review one particular process by which transformers are selected and new...
In recent years, interest in 155°C materials and Class F insulation systems has been increasing rapidly and apparently the general feeling in the motor industry is that use of such systems will gradually increase in the future. This feeling is made obvious by the amount of research and development work being done by various organizations to create and evaluate 155°C materials. The papers in this session...
Silicone dielectric materials, because of their unique properties, are used to improve reliability and to extend the life of electronic components and assemblies where: a. temperatures up to 250C are continuously encountered; b. transient temperatures up to 400 or 500C are encountered; c. repairability or depotting of encapsulated equipment is desirable; d. temperatures down to −70C are encountered;...
I have been asked to speak to you today on "How to Introduce a New Product". This sounds simple enough on the surface — and would be if we were discussing techniques involved in getting an appealing, uncomplicated, consumer-type product to the market. But we are not. We are in a materials $$ a component products — business, and nobody buys what we are selling on impulse alone. Far from it.
The first electrical property we shall discuss is the d.c. conductivity. Gases have essentially no d.c. conductivity beyond that due to stray charges produced by various radioactive processes always present. The reason for this lack of conductivity even when the gas is composed of a substance quite conducting in the liquid state is the difficulty of separating charge in a medium of low dielectric...
When new materials are introduced into an established insulating system it is important to consider the effects of the new insulation system on the other insulating materials in the system. Gaseous by-products and liquid exudates from one unstable component may degrade the entire system. For this reason epoxy resin systems have been developed which are compatible with conventional wire enamels, with...
The recent development of new alumina filled, highly track resistant insulating materials has focused attention on the new ASTM "Suggested Method of Test for Dust and Fog Tracking Resistance of Electrical Insulating Materials", which unfortunately requires 200 to 1000 hours to evaluate the better materials of this class. The required long duration of the test has been a serious limitation...
Mica segments have been used for commutator insulation for about seventy years. The type produced at the turn of the century was very inferior to that being used today. It certainly would not survive the compressive force, temperature requirements, or spin test exerted or required of this more modern era.
New and Challenging fields have been opened by these copper and aluminum film insulated wires The upgrading of temperatures for electrical apparatus and controls generally goes hand-in-hand with the reduction of overall size and weight of the equipment. In the pursuit of size and weight reduction, each and every component of the total unit must sooner or later be subjected to intelligent scrutiny...
The advances in insulating materials in the past few years have been major indeed. Yet the users of electrical apparatus are continually imposing new demands on those who manufacture the products containing insulation and upon the technology of the materials themselves. Controls, motors and other devices are now becoming physically smaller with respect to the duties they must perform. The result is...
Much time, effort, and money are being spent today to develop new and exotic insulation for rotating electrical equipment. Insulation specialists are able to determine to the most minute detail the chemical, physical, and electrical characteristics of the insulation. But the reliability factor is almost forgotten.
FIBERGLAS∗ yarns are manufactured by melting glass at $$ high temperature (2400°F–2800°F) in specially made bushings of furnaces equipped with very small holes in the bottom. As the molten glass runs through these holes, the fibers are pulled at a very high rate of speed to reduce the diameter to the desired size. As the fibers are being pulled out of the bushing a binder is applied to them which...
The last twenty years have covered a period which has seen drastic changes in the insulating materials used in electric motors. The method of using these materials, however, has remained virtually unchanged. This paper will attempt to illustrate how a motor is insulated and why. The comparison of the virtues of the newer materials with the old standbys will no doubt be the subject of papers being...
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