| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a three-phase transformer that reduces its cost by reducing the using amount of shield materials while controlling the loss generated in each lower-core clamping metal fitting of the three-phase transformer within an allowable range. Ž<P>SOLUTION: Each lower-core clamping metal fitting 5 of the three-phase transformer whose shape is hollow and rectangular in its cross-sectional view is formed so that its longitudinal length is larger than the length of a lower yoke of the transformer, and is such constituted that refrigerant passing ports are punched in its upper horizontal surface 5a opposed to the lower end of the winding of the transformer and working holes 14 punched in its non-contacting vertical surface 5b with the lower yoke 3 are closed with insulating covers 15. A non-magnetic shield 8c is disposed in its contacting vertical surface 5d with the lower yoke 3 of the clamping metal fitting 5 from both longitudinal ends of the clamping metal fitting 5 to the place of the lower yoke 3 in end-portion core legs 1U, 1W. A non-magnetic shield 8c is disposed in its whole upper horizontal surface 5a excluding the refrigerant passing ports 13. A non-magnetic shield 8b is disposed in the whole longitudinal region of its non-contacting vertical surface 5b and from its upper end to the place of the insulating covers 15. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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