Abstract: Operating shaft 4 allows disconnecting switch-side and earthing switch-side moving contacts 7a and 7b to linearly reciprocate with the rotation of operating shaft 4. Operating shaft 4 has two-hole lever 5 allow an arc motion. Each one end of two curved links 6a and 6b is connected to two-hole lever 5 and the other end of two curved links 6a and 6b is respectively connected to the disconnecting switch-side moving contact or the earthing switch-side moving contact. When the two connecting points are axisymmetric with respect to the bisector, both the disconnecting switch and the earthing switch are in an open state; when two-hole lever 5 moves at a predetermined angle to the disconnecting switch-side, the disconnecting switch is in a closed state; and when two-hole lever 5 moves at a predetermined angle to the earthing switch-side, the earthing switch is in a closed state.

Abstract: Bus container 1 of cylindrical shape is filled with insulating gas and main circuit conductor 2 is housed with bus container 1 in taut condition. Bus container 1 has flange 3. Current transformer container 4 is installed adjacently to bus container 1. Current transformer container 4 includes inner cylinder 5 and outer sealing member 6. On the periphery of inner cylinder 5, three current transformers 11 are provided interposing insulative cushioning material 10. Other longitudinal end of inner cylinder 5 and bus container 1 are arranged so that insulation gap 9 is formed in between. Between inner cylinder 5 and outer sealing member 6 on insulation gap 9 side, varistor 15 of which resistance varies depending on a applied voltage is electrically connected through bonding conductor 16. Varistor 15 turns into a conducting state when a surge voltage over a predetermined intensity is applied.

Abstract: Operating shaft 4 allows disconnecting switch-side and earthing switch-side moving contacts 7a and 7b to linearly reciprocate with the rotation of operating shaft 4. Operating shaft 4 has two-hole lever 5 allow an arc motion. Each one end of two curved links 6a and 6b is connected to two-hole lever 5 and the other end of two curved links 6a and 6b is respectively connected to the disconnecting switch-side moving contact or the earthing switch-side moving contact. When the two connecting points are axisymmetric with respect to the bisector, both the disconnecting switch and the earthing switch are in an open state; when two-hole lever 5 moves at a predetermined angle to the disconnecting switch-side, the disconnecting switch is in a closed state; and when two-hole lever 5 moves at a predetermined angle to the earthing switch-side, the earthing switch is in a closed state.

Abstract: Bus container 1 of cylindrical shape is filled with insulating gas and main circuit conductor 2 is housed with bus container 1 in taut condition. Bus container 1 has flange 3. Current transformer container 4 is installed adjacently to bus container 1. Current transformer container 4 includes inner cylinder 5 and outer sealing member 6. On the periphery of inner cylinder 5, three current transformers 11 are provided interposing insulative cushioning material 10. Other longitudinal end of inner cylinder 5 and bus container 1 are arranged so that insulation gap 9 is formed in between. Between inner cylinder 5 and outer sealing member 6 on insulation gap 9 side, varistor 15 of which resistance varies depending on a applied voltage is electrically connected through bonding conductor 16. Varistor 15 turns into a conducting state when a surge voltage over a predetermined intensity is applied.

Abstract: A gas circuit breaker 40 automatically interrupts a fault current such as ground fault current flowing through a conductor 61 of a bus line 60. A high speed grounding switch 10 performs a higher grounding and its releasing operation than the open and close operation of the gas circuit breaker 40 during the open and close operation thereof and guarantees the current interrupting performance and the inter-electrode insulation performance of the gas circuit breaker 40. In association with the electrode arrangement of a disconnecting switch 20, bus lines 60A and 60B are disposed in horizontal direction, a stationary electrode 13 of the high speed grounding switch 10 is provided at the constitutional unit 21 of the disconnecting switch 20 so as to locate on the same straight line as the central axis of the bus line and the movable electrode 11 at the ground side is closed along the same straight line as the central axis of the bus line.

Abstract: An instrument current transformer for a main power cable which is composed of three power cables for three phases disposed in a power cable laying hole and three current transformer coils for the three phases, each of the three current transformer coils surrounding a corresponding one of the three power cables, the instrument current transformer including: a plurality of upper circumferential installation unit members disposed near an end portion of the power cable laying hole along circumference sides of an opening portion of the power cable laying hole, each of the upper circumferential installation members being provided with at least one securing portion extending in a radial direction and the upper circumferential installation unit members being secured to the end portion of the power cable laying hole via respective at least one securing portions; three axial installation members for the three phases, each extending along corresponding ones of the three power cables, first ends of the axial installation