Fuse devices and electrical systems using the fuse devices are disclosed, with the fuse devices having internal components to cause a fuse blown event when the pre-determined current level is reached through the contacts. The internal components can comprise a levitation actuator that causes separation between one or more of the contacts as the current level approaches the predetermined level. This causes contact levitation and arcing, which increases the resistance at the contact being separated. This in turn causes the current through the contacts to seek another path that in the embodiments herein is a path to a pyro feature. The current activates the pyro feature, which causes the contacts to separate and puts the fuse device in “fuse blown” condition where currents can no longer flow through the contacts.

A protection device for an electrical circuit comprising at least one circuit breaker comprising a control zone, suitable for receiving a tripping signal (S), and a power zone for the passage of electric current. The device also comprises a control circuit configured to produce and transmit the tripping signal to the control zone. The device further comprises a fuse connected in series between the first conductor and the circuit breaker and capable of supplying a supply voltage (V) to the control circuit, the control circuit being connected between the fuse and the control zone.

An interrupter includes a gas producer, an actuator pin, and an electrical conductor. The electrical conductor includes a first terminal portion, a first separable portion, a second terminal portion, and a second separable portion. The second separable portion is electrically connected to the first separable portion in parallel. A first timing when the first separable portion starts to be cut off from the first terminal portion is earlier than a second timing when the second separable portion starts to be cut off from the second terminal portion.

A fusible switch disconnect device includes a housing adapted to receive at least one fuse therein, and a switchable contact for connecting the fuse to circuitry. A tripping mechanism and control circuitry are provided to move the switchable contact to an open position in response to a predetermined electrical condition.

A fusible switch disconnect device includes a housing adapted to receive at least one fuse therein, and a switchable contact for connecting the fuse to circuitry. A tripping mechanism and control circuitry are provided to move the switchable contact to an open position in response to a predetermined electrical condition.

A switch-fuse module and a ring main unit. The switch-fuse module includes: a housing having therein a first enclosure including a first insulating gas and a second enclosure including a second insulating gas; at least one switch disconnector arranged within the first enclosure; and at least one fuse at least partially surrounded by the second enclosure; wherein each of the first insulating gas and the second insulating gas has a global warming potential less than a global warming potential of SF6, and the first enclosure is different and separate from the second enclosure.

A switch-fuse module and a ring main unit. The switch-fuse module includes: a housing having therein a first enclosure including a first insulating gas and a second enclosure including a second insulating gas; at least one switch disconnector arranged within the first enclosure; and at least one fuse at least partially surrounded by the second enclosure; wherein each of the first insulating gas and the second insulating gas has a global warming potential less than a global warming potential of SF6, and the first enclosure is different and separate from the second enclosure.

A protection structure is disclosed and is applied in a fuse link switch. The fuse link switch comprises: an insulator, a fuse tube including an upper connection portion and a lower connection portion, an upper-end fixing unit, a lower-end fixing unit, and a toggle mechanism, wherein the upper connection portion is connected with a pull hook. The protection structure comprises at least one electrically insulating shielding layer covering at least one of the upper-end fixing unit, the pull hook, the upper connection portion, the lower connection portion, the lower-end fixing unit, and the toggle mechanism through overmolding technique.

A switch-fuse module and a ring main unit. The switch-fuse module includes: a housing having therein a switch enclosure including an insulating gas and a cable compartment that is different and separate from the switch enclosure; at least one switch disconnector arranged within the switch enclosure; and at least one fuse canister with a vertically oriented longitudinal axis; wherein the fuse canister i) is adapted to receive a fuse, and ii) is arranged within the cable compartment, and the insulating gas has a global warming potential less than a global warming potential of SF6.

A fuse in form of breaking fusant by fusing breaking and mechanical breaking includes hollow shell; arc extinguishing medium filled in the shell; at least one piece of fusant arranged in the shell; and conductive terminals provided as penetrating through shell wall and capable to be connected to external circuit, two ends of the fusant are respectively connected with the conductive terminals, at least one breaking device that mechanically breaks the fusant is provided in the shell; driving device arranged outside the shell, after receiving external excitation signal, drives the breaking device to break the fusant in one of linear and rotational displacement modes or their combination; blocking structures are arranged between the breaking device and the shell wall; and the fusant located in the arc extinguishing medium is provided with weak positions where mechanical breaking strength of the fusant is reduced and fusing is easy to be achieved.