| 摘要 |
FIELD: transformer engineering. SUBSTANCE: transformer has magnetic core, high- voltage winding, at least one low-voltage winding, and one high- voltage lead, all mounted in molded insulating case. Socket provided in its top part houses high-voltage fuse connected to high-voltage lead. Fuse has two bases, body of gas-producing material accommodating extension spring and low-power metal- film resistor that functions as fusible link. One of fuse bases has at least one hole opposing at least one hole provided in high-voltage lead and inner surface of the latter has annular slot facing hole in base and joined with lead hole. Rated value of resistor is found from expression where rr,rtd is rated value of resistor, Ohm; Pr.rtd is rated power of resistor, W; is overpower factor of resistor affording operation of fuse within time tpr; Ipt is current through fuse operating within time tpr (found from time-current characteristic of fuse), A; ITr.1max is maximum permissible current of potential transformer high-voltage winding, A; Ir.rtd is rated current of resistor, A. EFFECT: enhanced reliability of protective gear. 1 cl, 3 dwg
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