EP0280189A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Surge arrester
Assignee: ABB AB
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Filing: 1988-02-18
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Granted: —
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Expires: 2008-02-18
Abstract
Abstract An open surge arrester comprises, on the one hand, and active part (1,2,3) with a number of surge arrester elements (10) of a metal oxide varistor material, arranged between two end fittings (4,5), and, on the other hand, a retaining part with at least one rod (6) of an insulating material for mechanically holding the surge arrester together. Both, the active part and the retaining part are exposed to the environment surrounding the surge arrester and are individually profiled to provide an extended creep distance between the end fittings (4,5).
Inventors
- 👤 Bengt Johnnerfelt
- 👤 Bengt Thors
- 👤 Peter Stengard
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 12:01
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/10; H01C7/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
100 words
Surge arrester comprising, on the one hand, an active part (1,2,3) including at least one substantially cylindrical surge arrester element (10) of a metal oxide varistor material, arranged between two end fittings, and, on the other hand, a retaining part including at least one rod (6) of insulating material extending between the end fittings for mechanically holding the surge arrester together, characterized in that both the active part (1,2,3) and the retaining part (6) are exposed to the environment surrounding the surge arrester and are individually profiled to provide a creep distance of sufficient length between the end fittings (4,5).
Claim 2
Dependent Claim
100 words
Surge arrester comprising, on the one hand, an active part (1,2,3) including at least one substantially cylindrical surge arrester element (10) of a metal oxide varistor material, arranged between two end fittings, and, on the other hand, a retaining part including at least one rod (6) of insulating material extending between the end fittings for mechanically holding the surge arrester together, characterized in that both the active part (1,2,3) and the retaining part (6) are exposed to the environment surrounding the surge arrester and are individually profiled to provide a creep distance of sufficient length between the end fittings (4,5).
Claim 3
Dependent Claim
40 words
Surge arrester according to Claim 1, characterized in that the active part (1,2,3) comprises a plurality of surge arrester elements arranged coaxially in a stack, the end surfaces of said surge arrester elements being provided with low resistive contact layers.
Claim 4
Dependent Claim
63 words
Surge arrester according to Claim 1 or 2, in which the envelope surfaces of the surge arrester elements (10) are tightly surrounded by annular protective members (11,12) of insulating material, which are formed and arranged so as to overlap each other around adjacent surge arrester elements, characterized in that the protective members are formed with at least one creep distance-extending annular projection (13).
Claim 5
Dependent Claim
77 words
Surge arrester according to Claim 1 or 2, characterized in that the surge arrester element (10) is formed at its envelope surface with a plurality of creep distance-extending annular projections arranged one after the other in the axial direction of the surge arrester element, said projections being of the same material as the ma terial in the rest of the surge arrester element and forming together with the rest of the surge arrester element a coherent unit.
Claim 6
Dependent Claim
39 words
Surge arrester according to Claim 4, characterized in that the envelope surface of the surge arrester element is provided with a protective coating of an electrically insulating material, said coating being formed and secured on the surge arrester element.
Claim 7
Dependent Claim
31 words
Surge arrester according to Claim 5, characterized in that the coating consists of a layer of a polymer or elastomer, or of a layer of glass, or of a ceramic material.
Claim 8
Dependent Claim
47 words
Surge arrester according to Claim 1 or 2, characterized in that the active part (e.g. 1) is provided with a tightly surrounding casing, applied by means of shrinkage and provided with grooves, of a plastic or rubber material, shrinkable by heating and being resistant to creeping current.
Claim 9
Dependent Claim
66 words
Surge arrester according to any of the preceding Claims, characterized in that the at least one rod (6), which is arranged for mechanically holding the surge arrester together, is threaded or grooved in such a way that the creep distance along the rod between the end fittings of the surge arrester is at least 30% longer than for a corresponding rod with a purely circular-cylindrical shape.
Claim 10
Dependent Claim
45 words
Surge arrester according to any of Claims 1 to 7, characterized in that the rod (6), which is arranged for mechanically holding the surge arrester together, is plain and is covered with a creep distance-extending, shrunk-on casing in the form of a grooved shrinking hose.
Claim 11
Dependent Claim
41 words
Surge arrester according to any of the preceding Claims, characterized in that its active part comprises a plurality of columns (1,2,3) arranged side-by-side in parallel between the end fittings, each of said columns including one or more surge arrester elements (10).
References Cited (Backward Citations)
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