EP0283189B1
Expired / Lapsed
EP
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Electrical ring main unit
Assignee: Schneider Electric Ltd
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Filing: 1988-03-08
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Granted: 1992-12-16
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Expires: 2008-03-08
Abstract
Abstract A three-phase electrical ring main unit comprising a lower chamber module (30) having a wall structure formed from insulating resin material; three input contacts (35), one for each phase, mounted within the lower chamber; three lower switching contacts (37), each mounted within the lower chamber for movement between different switching positions; insulating closure means (55) closing the top of the lower chamber; three output contacts (49), one for each phase, carried by and exposed on a lower face of the closure means; three busbar contacts (59 to 61), each electrically connected to a respective output contact, carried by and exposed on an upper face of the closure member (55); an upper chamber module (31) having a wall structure formed from insulating resin material; means (32) securing the upper chamber above the lower chamber; three tee-off contacts (85), one for each phase, mounted within the upper chamber; and three upper switching contacts (83), each mounted in the upper chamber for movement between different switching positions; one switching position of the lower switching contacts effecting electrical connection between the input contacts and their associated output contacts; and one switching position of the upper switching contacts effecting electrical connection between the busbar contacts and their respective tee-off contacts.
Inventors
- 👤 Martin Christopher Oakes
- 👤 Graham David Scully
- 👤 Michael Adams
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 21:10
CPC Classifications
H; H02; H02B; H02B13/00; H02B13/02; H02B13/035; H02B13/0352; H01; H01H; H01H31/00; H01H31/003
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
275 words
A three-phase electrical ring main unit comprising a housing, three input contacts (35), one for each phase, mounted in a lower part of the housing; three output contacts (49), one for each phase; three lower switching contacts (37) each mounted in a lower part of the housing for movement between different switching positions; three busbar contacts (59 to 61), each connected to a respective output contact; three tee-off contacts (85), one for each phase, mounted in an upper part of the housing; and three upper switching contacts (83) each mounted in an upper part of the housing for movement between different switching positions; one switching position of the lower switching contacts effecting electrical connection between the input contacts (35) and their associated output contacts (49); and one switching position of the upper switching contacts effecting electrical connection between the busbar contacts (59 to 61) and their respective tee-off contacts (85); characterised in that the housing comprises a lower chamber module (30) and an upper chamber module (31) each having a wall structure formed from insulating resin material; the input contacts (35) and the lower switching contacts (37) are all mounted within the lower chamber module (30); the tee-off contacts (85) and the upper switching contacts (83) are all mounted within the upper chamber module (31); the top of the lower chamber module (30) is closed by insulating closure means (55); the output contacts (49) are exposed on a lower face of the closure means (55) and the busbar contacts are exposed on an upper face of the closure means (55); and means (32) securing the upper chamber module (31) above the lower chamber module (30).
Claim 2
Dependent Claim
47 words
A ring main unit according to claim 1 in which the insulating closure means is a base (55) formed integrally with the wall structure of the upper chamber module (31), and closing an open top of the lower chamber module (30) when these modules are secured together.
Claim 3
Dependent Claim
39 words
A ring main unit according to claim 1 or claim 2 in which the upper chamber module (31) has an open top, which is closed by a lid (91) secured to the wall structure of the upper chamber module.
Claim 4
Dependent Claim
36 words
A ring main unit according to any one of the preceding claims in which the outer surface of the wall structure of each chamber module (30, 31) is screened by an electrically conductive coating applied thereto.
Claim 5
Dependent Claim
111 words
A ring main unit according to any one of the preceding claims in which the input contacts (35) have axes that are substantially parallel and lie in a first plane, the output contacts (49) have axes that are substantially parallel and lie in a second plane substantially perpendicular to the first plane, the busbar contacts (59 to 61) have axes that are substantially parallel and lie in a third plane substantially perpendicular to the second plane and at an angle to the first plane, and each busbar contact is electrically connected to its respective output contact by a respective busbar (56 to 58) moulded in situ in the closure means (55).
Claim 6
Dependent Claim
73 words
A ring main unit according to claim 5 in which each respective busbar (56 to 58) has an extension (56a to 58a) electrically connected to an auxiliary tee-off contact, the auxiliary tee-off contacts having conductors that pass through the wall structure of the upper chamber module in a direction different to the direction in which conductors connected to the tee-off contacts pass through the wall structure of the upper chamber module (Fig 6).
Claim 7
Dependent Claim
117 words
A ring main unit according to any one of the preceding claims in which the input contacts (35) are electrically connected to supply conductors (34) entering the lower chamber module through the wall structure thereof; the lower switching contacts (37) are pivotally mounted on respective input contacts; three earthing contacts (48), one for each phase, are mounted within the lower chamber module and are electrically connected to earth connection points (50) lying outside the lower chamber module; and the lower switching contacts are moveable in unison between an off position, an on position wherein they connect respective input and output contacts (35, 49), and an earth position wherein they connect respective input and earth contacts (35, 48).
Claim 8
Dependent Claim
70 words
A ring main unit according to any one of the preceding claims in which the lower chamber (30) also houses a second set of three input contacts (51), a second set of three lower switching contacts (52) and a second set of three output contacts (54); in an arrangement that is substantially a mirror image of the first aforesaid input contacts (35), lower switching contacts (37) and ouput contacts (49).
Claim 9
Dependent Claim
124 words
A ring main unit according to any one of the preceding claims in which the tee-off contacts (85) are electrically connected to tee-off conductors (74) entering the upper chamber module (31) through the wall structure thereof; the upper switching contacts (83) are pivotally mounted on respective tee-off contacts; three tee-off earthing contacts (90), one for each phase, are mounted within the upper chamber module and are electrically connected to tee-off earth connection points lying outside the upper chamber module; and the upper switching contacts (83) are moveable in unison between an off position, an on position wherein they connect respective busbar and tee-off contacts (59 to 61, 85), and its tee-off earth position wherein they connect respective tee-off and tee-off earth contacts (85, 90).
Claim 10
Dependent Claim
51 words
A ring main unit according to claim 8 in which arc-extinction means (76 to 79) are associated with each busbar contact to extinguish any arc struck between a busbar contact (59 to 61) and its associated upper switching contact (83) when the latter moves from the on to the off position.
References Cited (Backward Citations)
No citation records indexed.
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