A switching device has a commutation flow path, a first isolating gap, and a second isolating gap. The first isolating gap and the second isolating gap form an electrical series circuit which is arranged parallel to the commutation flow path. The second isolating gap has a first contact, a second contact, and a third contact. The first contact is a moving contact. The first contact is mounted movably along a switching axis from a first galvanic contacting position with the second contact to a second galvanic contacting position with the third contact. In the second contacting position, a mechanical contact force acts between the first contact and the third contact in a radial direction.

An arc-extinguishing apparatus includes a first device, main loop electrodes of the first device include a first electrode and a second electrode; and a switch, which needs to be subjected to arc extinguishing and includes a first end, a second end and a contact bridge, the first electrode and the second electrode are respectively configured to connect to the first end and the second end. The apparatus further includes a capacitor and a first voltage detection switch, the first voltage detection switch and a third electrode and the second electrode of the first device constitute a first series circuit, the contact bridge and the second end constitute a second series circuit, the first series circuit is connected in parallel to the second series circuit, and the capacitor is connected in parallel to the second series circuit.

An arc-extinguishing apparatus includes a first device, main loop electrodes of the first device include a first electrode and a second electrode; and a switch, which needs to be subjected to arc extinguishing and includes a first end, a second end and a contact bridge, the first electrode and the second electrode are respectively configured to connect to the first end and the second end. The apparatus further includes a capacitor and a first voltage detection switch, the first voltage detection switch and a third electrode and the second electrode of the first device constitute a first series circuit, the contact bridge and the second end constitute a second series circuit, the first series circuit is connected in parallel to the second series circuit, and the capacitor is connected in parallel to the second series circuit.