xiv LIST OF ILLUSTRATIONS 



Seating Oarves of Oil Transformer. (Sec Fig. 77 for Key to 



1'o-itions of Thermometers for Curves A. B, ( ' and I )) .1 19 



77. Diagram showing Positions of Thermometers for the Hfatin.ir 



Curves shown in Fig. 70 . . . . . 1-0 



78. Heating Curves for 5-kva Transformer in Air and ( )il. ( 'nrve 



A in ( asc without Oil. Curve B in Case with Oil . .121 



79. Heating Curve for 50-kva Transformer in Air and in Oil . l'-M 



80. Curves showing Temperature Rise of Transformers in Air and 



in Oil . . . . ' 122 



81. Curve showing Time for 50-kva Transformer to reach 40 C. 



at Various Loads . . 12:J 



82. Curves showing Quantity of Oil used for Single-phase Trans- 



formers . . . . . . . . . .137 



83. Temperature Curves for 10-kva Single-phase Oil-cooled Trans- 



former in Small and Large Cases 139 



84. Cases for 10-kva Transformer Temperature Test, showing 



Various Positions of Thermometers 1 1 1 



85. Temperature Test on a 10-kva Single-phase Transformer, with 



a Load of 8 kw (for Positions of Thermometei s Tl, T2, T3, 



see Fig. 84) 142 



85A. Elevation of Ribbed Cast-iron Case 1 Hi 



85s. Plan of Ribbed Cast-iron Case 147 



86. Method of Jointing the Sides and Bottom of a Transformer . 



Case 150 



87. Westinghouse 1000-kva 100 000-volt 60-cycle Oil-immersed 



Self -cooled Transformer 152 



88. Johnson and Phillips' 600-kva Transformer for Oil Immer- 



sion 153 



89. Diagram showing Construction of an Air-blast Trans- 



former 155 



90. Coils of a Shell-type Air-blast Transformer after Completion 



of Impregnating Process . . . . . . .156 



91. Diagrammatic Sketch of American General Electric Co.'s 



Air-blast Transformers . .. 157 



92. 550-kva 50-cycle Air-blast Transformer by the Westinghouse 



Co 15s 



93. Diagram showing Arrangement of Transformers and Blowers . 159 



94. Bank of Air-blast Transformers KM) 



95. 10000-kva Oil-insulated Water-cooled Westinghouse Trans- 



formers .......... 163 



96. View of the Interior of the American General Electric Co.'s 



10000-kva 100 000-volt 60-cycle Design for a Water- 

 cooled Oil immersed Transformer before the Cooling Coils 

 have been Mounted 164 



97. American General Electric Co.'s 10 000-kva 100 000-volt 



Design with the Cooling Coils in Place .... 165 



