A high-voltage power switch, preferably with a dead tank design, contains: a switching unit that has a switching device and an actuation element that is axially movable in relation to a longitudinal axis of the switching device to actuate the switching device and a closing resistor unit that has a closing resistor arrangement and an adjusting element that is axially movable in relation to a longitudinal axis of this closing resistor arrangement to actuate the closing resistor arrangement. The actuation element is coupled to the adjusting element in order to move the latter. Accordingly, the longitudinal axis of the switching unit and the longitudinal axis of the closing resistor unit are spaced apart, and the actuation and adjusting elements are coupled by a coupling device of the high-voltage power switch.

An improved circuit breaker is disclosed herein. The improved circuit breaker includes one or more main contacts and only one resistor contact. The only one resistor contact is connected in parallel with at least one of the one or more main contacts.

A high-voltage power switch, preferably with a dead tank design, contains: a switching unit that has a switching device and an actuation element that is axially movable in relation to a longitudinal axis of the switching device to actuate the switching device and a closing resistor unit that has a closing resistor arrangement and an adjusting element that is axially movable in relation to a longitudinal axis of this closing resistor arrangement to actuate the closing resistor arrangement. The actuation element is coupled to the adjusting element in order to move the latter. Accordingly, the longitudinal axis of the switching unit and the longitudinal axis of the closing resistor unit are spaced apart, and the actuation and adjusting elements are coupled by a coupling device of the high-voltage power switch.

An on-load tap changing apparatus includes a first switching unit connected to a first tap of a transformer provided in a power system and switching power supplied from the first tap, a first impedance changing unit connected in series with the first switching unit and increasing an impedance when the first switching unit executes a switching operation, a second switching unit connected to a second tap of the transformer and switching power supplied from the second tap, and a second impedance changing unit connected in series with the second switching unit and increasing an impedance when the second switching unit executes a switching operation. The on-load tap changing apparatus can suppress an arc at the time of switching, reduce deterioration of a switching unit, and have excellent durability.

An improved circuit breaker is disclosed herein. The improved circuit breaker includes one or more main contacts and only one resistor contact. The only one resistor contact is connected in parallel with at least one of the one or more main contacts.

A vacuum capacitor switch with pre-insertion contact includes first and second contact systems. The first contact system includes an annular stationary contact and an annular moving contact retained on a moving contact drive rod. A second contact system includes a moving contact retained on an end of the moving contact drive rod and a floating contact retained along the same axis as the second moving contact. Both contact systems are enclosed in a vacuum envelope. A mechanical adjustment system is provided for the floating contact, which allows it to be positioned so that the secondary moving contact and floating moving contact may engage at a set interval before the annular moving contact engages the annular stationary contact. A resistor or inductor is connected between the second contact system and a load to prevent a current in-rush into the load.

Disclosed is a supporting structure of a closing resistor unit for a circuit breaker which connects the closing resistor unit to the fixed portion through the first supporting plate and the second supporting plate to allow the closing resistor unit to move back and forth with respect to the fixed portion through the first supporting plate and to move up and down with respect to the fixed portion through the second supporting plate, whereby the closing resistor unit or its joints may be prevented from being damaged from impact.