Design of a 20,000 . y^^r^A u^^jOT*^ A/^. S the external diameter over the Insulation at thecenter will be 3x3=9 inches. Allow 4000 volts per layer, hence use 28 layeriof insu^tion alternating with 28 layers of tin-foil. The projec t ion of the terminal above the grounded plate (the cover of the transformer case) need not be so great as would be indicated by the application of the practical rule previously given for surface leakage distance; namely, that this distance shouM be ( kv/2) in., where kv. stands for the working pressure. The reason why a somev/hat shorter distanc
Design of a 20,000 . y^^r^A u^^jOT*^ A/^. S the external diameter over the Insulation at thecenter will be 3x3=9 inches. Allow 4000 volts per layer, hence use 28 layeriof insu^tion alternating with 28 layers of tin-foil. The projec t ion of the terminal above the grounded plate (the cover of the transformer case) need not be so great as would be indicated by the application of the practical rule previously given for surface leakage distance; namely, that this distance shouM be ( kv/2) in., where kv. stands for the working pressure. The reason why a somev/hat shorter distance is permissible is that zhe surface of the terminal proper has been cov- farered by varnish and asolid compound, and so as the enclosing cylinder is concerned, the stress alongthe surface of this cylinder will be fairly uni-form, eBpecially if a large flux-control shield isprovided, as feJiown in Fig. 9. In order to avoidthe formation of corona at the lower terminal (be-low the surface oif the oil) this end may conveni-ently be in t
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Keywords: ., bookcentury1900, bookdecade1920, bookiddesignof2000, bookyear1920
