EP2269204B1

EP2269204B1 - Modular electrical apparatus comprising protection means for preventing electric arcs

Info

Publication number: EP2269204B1
Application number: EP08763822A
Authority: EP
Inventors: Flavio Purgato
Original assignee: BTicino SpA
Current assignee: BTicino SpA
Priority date: 2008-04-21
Filing date: 2008-04-21
Publication date: 2012-03-28
Anticipated expiration: 2028-04-21
Also published as: PL2269204T3; RU2470403C2; RU2010147393A; CN101960548B; ES2384813T3; CN101960548A; EP2269204A1; SI2269204T1; WO2009130716A1; ATE551709T1

Abstract

A modular electrical apparatus (10) adapted to be installed inside an electric panel, comprising: a primary cased body (12); at least one electrical connection terminal (30) suitable for receiving an electrical conductive cable (32) for connecting the electrical apparatus (10) to said conductive cable; protective means (36, 38) for preventing electric arcs, which may be associated with said electrical connection terminal (30); and mechanical coupling means for coupling the protective means (36, 38) to said primary cased body (12. In particular, the mechanical coupling means allow to movably constrain the protective means (36, 38) to said primary cased body (12).

Description

The present invention relates to an electrical apparatus, and more particularly to a modular electrical apparatus according to the preamble of claim 1.
The present invention generally refers to the technical field of modular electrical apparatuses, such as electrical circuit breakers, adapted to be installed in an electric panel or distribution and protection panel for an electrical installation.
As is known, in civil as well as in industrial applications, electrical distribution installations are based on above said type of electrical apparatuses and panels.
Normally, these electrical apparatuses comprise at least one electrical connection input terminal or input clamp suitable for interacting with electrical conductive input cables for connecting said apparatuses to an electrical supply line. Normally, above said electrical apparatuses also comprise at least one electrical connection output terminal or output clamp suitable for interacting with electrical conductive output cables for connecting the electrical apparatus to a load circuit.
Electrical apparatuses of above said type are manufactured according to protection guidelines, which, among other things, impose minimum distances between adjacent terminals of same electrical apparatus and/or between terminals of adjacent electrical apparatuses which are installed in the electrical panel, both for input terminals and for output terminals.
These constraints are imposed in order to avoid formation of electric arcs or discharges between adjacent electrical conductive cables and/or electrical connection terminals.
Above said electric arcs may be caused for instance by connecting electrical apparatuses with electrical cables, in which the electrical conductor of the cable is exposed along a certain length in proximity to the connection terminals. This may be the case, for example, in electrical conductive cables in which excessive removal of insulating sheath has taken place, or when the sheath is shrunk due to prolonged and repeated overheating of same conductive cable.
Electrical discharges between adjacent conductors may also take place, even if the electrical apparatuses are properly connected, if a single electrical conducting wire of the wire bundle forming the electric cable extends beyond the bundle, dangerously approaching an adjacent electrical connection terminal and/or electrical cable.
The traditional solution in order to obviate to above said drawbacks, provides for the application of protective baffles of insulating material onto the electrical apparatuses. These protective baffles are particularly intended to be fixed on the external portion of above said electrical apparatuses, by using corresponding slots or fixing means which are provided for this purpose or are already present on casing of same apparatuses.
Protective baffles of above said type are usually sold separately from electrical apparatuses, in suitable packages, each containing a certain quantity of baffles, and are usually connected to said apparatuses after installation thereof, for example inside an electrical panel.
However, protective baffles of the known art have some drawbacks.
In the first place, there are drawbacks relating to the fact that connection of protective baffles to the electrical apparatuses is generally difficult. Usually one has to insert small extensions, which are provided on protective baffles, into small complementary slots, which are arranged on external casing of the electrical apparatuses. This requires, during baffle installation, at least an alignment step of baffle extensions and corresponding slots on electrical apparatus and an insertion step of extensions into same slots. These operations are moreover difficult due to small size of above said extensions. Moreover, it is to be noted that above said connection procedure is particularly clumsy and complicated if lighting is reduced.
It is to be underscored the fact that inconveniences connected with the installation of protective baffles of the known art are present when the electrical conductive cables are connected to electrical apparatuses before baffle installation as well as when these cables are connected after baffle installation. In fact, in the first case, electrical cables form an encumbrance for baffle installation whereas in the second case, baffles are an obstacle for connecting cables to the electrical apparatuses. In this latter case, in particular, during connection of electrical cables, hands of operator may inadvertently hit against protective baffles, for example causing their disconnection from the electrical apparatus.
Further drawbacks of protective baffles of the known art are related to the fact that during connection of baffles to the electrical apparatuses, above said small extensions may inadvertently break, requiring use of new protective baffles.
Moreover, the separating baffles may be damaged to the extent that small portions may remain locked inside the coupling slots provided on the electrical apparatus. This prevents insertion of replacement baffles, therefore requiring temporary removal or even replacement of the electrical apparatus, therefore increasing installation times of the baffles and corresponding installation costs.
Patent document FR 2787933 discloses an electrical apparatus comprising protective means associated to the electrical connection terminals of an electrical apparatus and which are constrained to the case body thereof. However, protective means disclosed in such document only serve for the purpose of preventing involuntary contacts with live electric parts of the electrical apparatus and not for preventing electric arcs between adjacent electrical conductive cables and/or electrical connection terminals. Patent documents GB 1517913 and EP 0881727 disclose barriers between adjacent connection terminals or phases.
The object of the present invention is to provide a modular electrical apparatus which avoids generation of arcs or electrical discharges between adjacent electrical connection terminals and/or electrical conductive cables, eliminating above said drawbacks of the known art.
This object is achieved by an electrical apparatus as defined and characterized by annexed claim 1, in its most general form, and by the dependent claims, which relate to particular embodiments.
A further object of the present invention is a group of parts and a modular electrical circuit breaker as defined by claim 14 and claim 15, respectively.
The invention will be readily understood by reading following detailed description of one of its embodiments, which is illustrative only and therefore in no way limiting, with reference to attached drawings, wherein:

fig. 1 shows a perspective view of a modular electrical apparatus according to an embodiment of the present invention, wherein the electrical apparatus is shown in a first operating arrangement;
fig. 2 shows a perspective view of modular electrical apparatus of fig. 1, in a second operating arrangement;
fig. 3 shows a perspective view of the electrical apparatus of fig. 1, wherein a lateral face of electrical apparatus is shown, which is opposed with respect to the one shown in fig. 1 and 2;
fig. 4 shows a perspective view of a part of the electrical apparatus of fig. 1, in greater detail;
fig. 5 shows a perspective view of a group of parts including three electrical apparatuses according to the present invention, in operating arrangement of fig. 2;
fig. 6 shows a perspective view of a currently preferred embodiment of a modular electrical apparatus according to the present invention, in a first operating arrangement;
fig. 7 shows a perspective view of the electrical apparatus of fig. 6, shown in a second operating arrangement; and
fig. 8 shows a perspective view of the electrical apparatus of fig. 6, wherein some parts are separated.

In the following description, same or like elements are provided with same reference numerals.
With reference to fig. 1, a modular electrical apparatus according to an embodiment of the present invention is generally shown at 10.
In the exemplary embodiment, apparatus 10 is in particular and in a non limiting way, a modular electrical circuit breaker, of the type adapted to be installed inside an electrical distribution and protection panel of an electrical installation.
Circuit breaker 10 comprises a primary cased body 12 provided with an internal portion facing the internal electrical-mechanical members provided for operating the circuit breaker, and an external opposed part.
More in detail, primary body 12 comprises a rear wall 14 and an opposed front wall 16. In particular, rear wall 14 is suitable for interacting with supporting means, in order to install circuit breaker 10, for example, inside an electrical panel. These mounting means of circuit breaker may comprise a mounting rail 20 (fig. 5), such as a DIN rail, of the type well known to the skilled in the art. On front wall 16 an operating lever 18 is provided, for switching circuit breaker 10 between a closed state and an open state.
In addition to above said front and rear walls, primary cased body 12 comprises an upper wall 22, an opposing lower wall 24 and a pair of mutually opposed side walls 26, 28 (fig. 1, 3).
In the embodiment of fig. 1, circuit breaker 10 comprises an upper electrical connection terminal 30 associated with upper wall 22, and a lower electrical connection terminal, which is not visible in the drawings, associated with lower wall 24.
Upper 30 and lower electrical connection terminals are each suitable for receiving a corresponding electrical conductive cable 32, 34 (fig. 5), or for receiving similar or equivalent connection means, for connecting the electrical circuit breaker to an electrical supply line and to a load circuit, respectively.
Circuit breaker 10 comprises protective or insulating means 36, 38, which may be associated to upper 30 and lower electrical connection terminals, for inhibiting or limiting generation of electrical arcs or discharges. More particularly, these electrical arc protecting means are in this example an upper protective baffle 36 and a lower protective baffle 38, which are associated to upper 30 and lower electrical connection terminals, respectively. In particular, these protective baffles 36, 38 are two generally plate-like elements.
As shown in fig. 1, protective baffles 36, 38 are movably constrained to primary cased body 12 of circuit breaker 10, by means of mechanical coupling means.
Protective baffles 36, 38 are constrained so as to be independently movable between a first and second end stop position, which are distinct and correspond to a non-protective operating arrangement (fig. 1) and a protective operating arrangement (fig. 2), respectively, of protective baffles 36, 38.
In the exemplary embodiment, mechanical coupling means provide a rotary connection of protective baffles 36, 38 to primary cased body 12. More in particular, protective baffles are hinged on one of opposed side walls 26, 28 of primary cased body 12, at two respective mutually opposed end portions of said primary body. In order to hinge each protective baffle to primary cased body, mechanical coupling means may be used, for example comprising a rivet, a screw, a pin and similar. Preferably, mechanical coupling means allow to constrain protective baffles in a substantially not removable way. However, according to an embodiment of the invention, the baffles may be also removably constrained to primary cased body.
According to an embodiment of the present invention, for example, protective baffles 36, 38, may be slidably, instead of rotatably, constrained to primary cased body.
Advantageously, protective baffles 36, 38 each comprise a protruding catching extension 36A, 38A, provided on an edge portion of respective protective baffle. These protruding extensions 36A, 38A may be operated for example manually, in order to move each protective baffle, starting from first end stop position (fig. 1 and 6).
Advantageously, protruding catching extensions 36A, 38A are inclined with respect to a peripheral edge portion 36B, 38B of respective protective baffle, forming an acute angle with this edge portion. In this way, each protruding catching extension 36A, 38A is inclined towards rear wall 14 of primary cased body 12, when corresponding protective baffle 36, 38 is in its first end stop position.
In the particular embodiment shown in fig. 1 to 5, protective baffles 36, 38 each comprise a protruding tooth 36C, 38C (fig. 2). In this example, each tooth 36C, 38C is connected to a portion of protective baffle 36, 38 comprising a corresponding reduced thickness portion 36D, 38D.
In the exemplary embodiments, circuit breaker 10 comprises two receiving seats 44, 46, inside of which are respectively movable protective baffles 36, 38.
In particular, in the first end stop position, protective baffles 36, 38 are almost completely received inside respective seats 44, 46, with the substantial exception of edge portions comprising protruding catching extensions 36A, 38A. On the contrary, in the second end stop position, protective baffles 36, 38 are at least partially positioned outside of receiving seats, significantly protruding from primary cased body 12 in order to provide respective protection. More particularly, in the second end stop position, portions of protective baffles 36, 38 protruding from cased body 12 of circuit breaker 10 are adjacent to upper 30 and lower electrical connection terminal, respectively.
Advantageously, each receiving seat 44, 46 is comprised of a cavity in the external portion of primary cased body 12 and more particularly of side wall 28 to which protective baffles 36, 38 are constrained.
Each receiving seat 44, 46 has a bottom wall 48, 50 joined with a peripheral wall 52, 54. Peripheral walls 52, 54 at least partially face peripheral edges 36B, 38B of protective baffles 36, 38, and each of them comprises at least an interruption adapted to be passed through by the corresponding protective baffle 36, 38 in order to allow such baffle to move from its first to its second end stop position, and vice versa.
In the embodiments shown, protective baffles 36, 38 are provided with a thickness smaller or equal to height of peripheral walls 52, 54 of receiving seats 44, 46, so that these baffles substantially don't protrude laterally from side wall 28 of primary body 12 to which said baffles are constrained.
According to embodiments shown, circuit breaker 10 comprises stopping means for stopping protective baffles at least at second end stop position. In the embodiment of the invention shown in fig. 1 to 5, stopping means comprise abutment portions 56, 58, against which protruding teeth 36C, 38C (fig. 2) of protective baffles 36, 38 abut, when protective baffles are in the second end stop position.
In the embodiments shown, circuit breaker 10 comprises approaching means 60, 62, also substantially plate-like, which are adapted to interact with the reduced thickness portions 36D, 38D of protective baffles 36, 38. In particular, approaching means 60, 62 are each adapted to define a channel between the bottom walls 48, 50 of respective receiving seats 44, 46 and same approaching means. This channel is adapted to at least partially receive the reduced thickness portion 36D, 38D of respective protective baffle, when said baffle is positioned at or near the first end stop position (fig. 1 and 6).
More particularly, approaching means 60, 62 interact with reduced thickness portions 36D, 38D in order to maintain contact between the protective baffles 36, 38 and the bottom walls 48, 50 of receiving seats 44, 46, when protective baffles 36, 38 are positioned at or near the first end stop position.
According to the embodiments shown, in particular, approaching means 60, 62 have a thickness substantially corresponding to depth of reduced thickness portions 36D, 38D, so that they do not substantially protrude, in a lateral direction, over the side wall 28 of primary cased body 12.
Installation of circuit breaker 10 inside the electrical panel is preferably accomplished in the following way.
Rear wall 14 of circuit breaker is approached to the electrical apparatus mounting rail 20 (fig. 5), in order to couple the circuit breaker to same rail. In this condition, protective baffles 36, 38 are in particular disposed in the first end stop position.
Once the circuit breaker has been coupled to the rail, upper 30 and lower electrical connection terminals are connected to respective electrical conductive cables 32, 34.
Afterwards, protective baffles 36, 38 are moved from first to second end stop position, by manually operating protruding catching extensions 36A, 38A, for example, by pulling with a finger of an hand these protruding extensions towards the front wall 16 of the circuit breaker.
It is clear that above said installation operations may be accomplished in a similar way on a group of parts including two or more modular circuit breakers according to the present invention.
Based on above description, it is therefore possible to understand how a modular electrical apparatus according to the present invention may solve above said problems with reference to the known art.
By advantageously providing protective baffles movably constrained to primary cased body of electrical apparatus, it is possible to considerably reduce time required for setting the protective baffles in the protective arrangement, in particular when lighting is reduced. In fact, protective baffles are preferably integral part of electrical apparatus and may be brought into protective condition by a simple rotation, without the need for complicated and difficult coupling operations, which are required by protective baffles according to the known art.
Moreover, since there are no parts in the protective baffles, which have to be inserted into slots provided on casing of electrical apparatuses, the possibility that protective baffles and electrical apparatus may inadvertently break is substantially eliminated.
By conveniently providing a protruding catching extension on the protective baffles, it is possible to easily move the baffles from first to second end stop position. This is particularly useful when the electrical apparatuses are mounted in an adjacent arrangement, wherein respective side walls are facing each other and are substantially adhering to each other (fig. 5). In this condition, and particularly when the protective baffles are in the first end stop position (fig. 1 and 6), protruding catching extensions are in fact essentially the only catching part available for moving the protective baffles.
Moreover the fact that the moving extensions are inclined towards the rear wall of electrical apparatus when protective baffles are in the first end stop position, further facilitates moving of protective baffles when the protective baffles are in such position and the electrical apparatuses are connected to respective electrical conductive cables. Moving of the protective baffles may in fact be readily accomplished for example by inserting a finger nail in the acute angle defined by the protruding catching extension and peripheral edge of protective baffle.
By providing receiving seats for the protective baffles, defined by cavities in side wall to which the protective baffles are constrained and having a depth substantially corresponding to thickness of protective baffles, it is advantageously possible to place the single electrical apparatuses side by side along respective side walls, in order to form compact modular groups.
It is evident that modifications and changes may be introduced to above said description and illustrations, which are only provided as examples.
Fig. 6, 7 and 8 show a currently preferred embodiment of a modular electrical apparatus according to the present invention.
With reference to fig. 8, approaching means 60, 62 particularly comprise two coupling ears or flaps, which interact with respective reduced thickness portions 36D, 38D of protective baffles 36, 38. In this example, flaps 60, 62 interact with mechanical coupling means, for constraining protective baffles to primary cased body 12 of circuit breaker 10. In the example of fig. 8, mechanical coupling means comprise two rivets 64, 66, each suitable for passing through a bore 68, 70 provided on ears 60, 62 and an opposed bore 72, 74 provided on the protective baffles 36, 38, for constraining the protective baffles and the coupling elements 60, 62 to primary cased body 12.
According to the particularly preferred embodiment shown in fig. 6, 7 and 8, ears 60, 62 comprise blocking means for holding said ears substantially fixed when protective baffles move from first to second end stop position and vice versa.
Blocking means of this example comprise a notch 76, 78 provided on each ear 60, 62 and a complementary protrusion 80, 82, provided on primary cased body 12 of circuit breaker. Notches 76, 78 are adapted to receive complementary protrusions 80, 82, in order to avoid rotation of ears around rotation axis of respective protective baffles 36, 38.
According to the currently preferred embodiment of fig. 8, stopping means for stopping protective baffles 36, 38 at least in the second end stop position comprise snap blocking means.
In the example shown in fig. 6, 7 and 8, snap blocking means comprise an elastic tooth 84, 86 provided on each protective baffle and a first 88, 90 (fig. 7) and second 92, 94 (fig. 6) coupling cavity provided in each receiving seat 44, 46. When the protective baffles 36, 38 are in the first end stop position, elastic teeth 84, 86 are respectively received in first coupling cavities 88, 90. Engaging the protruding catching extensions 36A, 38A in order to move protective baffles from first end stop position, elastic teeth 84, 86 elastically load moving back away from bottom walls 48, 50 of respective receiving seats 44, 46. The elastic teeth remain elastically loaded until protective baffles 36, 38 reach second end stop position. At this end stop position, the elastic teeth snap back into the second coupling cavities 92, 94, releasing the elastic energy previously stored and locking the baffles in the protective operating arrangement.
Starting from second end stop position, returning protective baffles 36, 38 to a non-protective configuration only requires acting on elastic teeth 84, 86 in order to disengage them from second coupling cavities 92, 94 and then pushing on protective baffles, until they return to the first end stop position. Preferably, elastic teeth can be disengaged from second coupling cavities, inserting a tool in said cavities, for example a screwdriver, and acting with the tool on the elastic teeth for disengaging the elastic teeth from respective cavities.
It being understood the principle of the invention, the embodiments and the embodiment details will be able to be widely modified compared to what has been described and illustrated by way of non-limitative example only, without for this departing from the scope of the invention as defined in the appended claims.

Claims

A modular electrical apparatus (10) adapted to be installed inside an electric panel, comprising:
- at least an electrical connection terminal (30) suitable for receiving an electrical conductive cable (32) for connecting the electrical apparatus (10) to said conductive cable;

- a primary cased body (12) comprising a rear wall (14) suitable for interacting with supporting means (20) for installing the electrical apparatus (10), an opposed front wall (16), an upper wall (22) and an opposed lower wall (24) of which at least one may be associated with the electrical connection terminal (30), and a pair of mutually opposed side walls (26, 28);

- protective means (36, 38) which may be associated with said electrical connection terminal (30); and

- mechanical coupling means for coupling the protective means (36, 38) to said primary cased body (12), the mechanical coupling means allowing to movably constrain the protective means (36, 38) to said primary cased body (12);
characterized in that said protective means are means for preventing electric arcs and include at least one plate-like protective element (36, 38) constrained to one of said opposed side walls (28) of the primary cased body (12).
The electrical apparatus (10) according to claim 1, wherein said at least one plate-like protective element (36, 38) is movable between a first and second end stop position which are distinct each other, the first and second end stop positions corresponding to an operating non-protective arrangement and an operating protective arrangement, respectively, of said plate-like element (36, 38).
The electrical apparatus (10) according to claim 1 or 2, wherein the protective means (36, 38) are slidably constrained to said primary cased body.
The electrical apparatus (10) according to claim 1 or 2, wherein the protective means (36, 38) are rotatably constrained to said primary cased body.
The electrical apparatus (10) according to claim 1, wherein said primary cased body (12) comprises at least one receiving seat (44, 46) inside which is movable the protective plate-like element (36, 38), the receiving seat being a cavity of the side wall (28) to which said plate-like protective element is constrained.
The electrical apparatus (10) according to claim 5, wherein the plate-like protective element (36, 38) comprises a protruding catching extension (36A, 38A) provided on a respective edge portion, for moving said plate-like element between the first and second end stop position, and wherein the plate-like element (36, 38), in its first end stop position, is almost completely received inside the receiving seat (44, 46) with the exception of said edge portion, and in its second end stop position, it is positioned at least partially outside of said receiving seat (44, 46), significantly protruding from primary cased body (12) in order to provide respective protection.
The electrical apparatus (10) according to any of claims 2 to 6, including stopping means (56, 58, 84, 86, 88, 90, 92, 94) for stopping said plate-like protective element (36, 38) at least in its second end stop position.
The electrical apparatus (10) according to claim 7, wherein the stopping means (56, 58, 84, 86, 88, 90, 92, 94) comprise snap blocking means (84, 86, 88, 90, 92, 94) for blocking the plate-like element (36, 38) in the first and second end stop position, respectively.
The electrical apparatus (10) according to claim 1, wherein the plate-like protective element (36, 38) is substantially not protruding laterally from the side wall (28) of the primary cased body (12) to which it is constrained.
The electrical apparatus (10) according to claim 5, wherein the plate-like protective element includes a respective reduced thickness portion (36D, 38D), and wherein the electrical apparatus (10) comprises approaching means (60, 62) adapted to define a channel between said approaching means (60, 62) and the receiving seat (44, 46) of the plate-like protective element; the channel being in particular suitable for receiving said reduced thickness portion (36D, 38D) when the plate-like protective element is positioned at or near the first end stop position, and the approaching means (60, 62) being able to interact with the plate-like protective element (36, 38) for maintaining said protective element (36, 38) adherent with a portion of said receiving seat (44, 46).
The electrical apparatus (10) according to claim 10, wherein said approaching means (60, 62) substantially do not protrude laterally from the side wall (28) to which the plate-like element (36, 38) is constrained.
The electrical apparatus (10) according to claim 10 or 11, including blocking means (76, 78, 80, 82) for substantially fixing the approaching means (60, 62) when plate-like protective element (36, 38) moves from first to second end stop position and vice versa.
The electrical apparatus (10) according to claim 1, comprising at least two plate-like protective elements (36, 38), said plate-like protective elements (36, 38) being constrained to the same side wall (28) of the primary cased body (12).
A group of parts including a plurality of adjacent modular electrical apparatuses (10) according to any of preceding claims.
A modular electrical circuit breaker (10), comprising at least one electrical apparatus (10) according to any of claims 1 to 13.