| 摘要 |
PURPOSE:To make a cast molding into a product having a good corona characteristics and so on in a short time by the method wherein a coil present inside of a molded current transformer or transformer is conducted D.C. directly to be developed heat which hardens a casting material from periphery of the coil. CONSTITUTION:A coil 2 present inside a die 3 of a molded transformer of 6kV, 500kVA is vacuum-cast its periphery by an epoxy resin casting material 4. After that, periphery of the die 3 is covered with a heat insulator (rock wool) 5 and a coil terminal 10 present inside the die is previously insulated from the die 3 by an insulating plate 8 and a lead 12 fixed by a nut 9 is connected to a power source for the conduction of current. At first, the conduction is started setting a voltage and a current at 65V and 55A and hardening reaction of the casting material 4 is started by heat developed of the coil 2. In case of a molded transformer coil of the capacity, it can be released from the die 3 in 220min. |
