GB2239350A

GB2239350A - Insulating case for a circuit breaker

Info

Publication number: GB2239350A
Application number: GB9026242A
Authority: GB
Inventors: Noel Lecorre; Michel Lazareth; Maurice Burrial
Original assignee: MERLIN GERLIN
Current assignee: MERLIN GERLIN
Priority date: 1989-12-22
Filing date: 1990-12-03
Publication date: 1991-06-26
Anticipated expiration: 2010-12-03
Also published as: GB2239350B; GB9026242D0; FR2656464B1; FR2656464A1

Abstract

An insulating case for a circuit breaker comprises an intermediate frame 20 positioned between first 28 and second (34, not shown) covers so as to define a first compartment on one side of the frame 20 housing the neutral line and the protection means and a second compartment on the other side of the frame 20 housing the phase line. Two recesses accommodating phase terminals are located at opposite sides of the case so as to face the second compartment. First and second case portions 30, 32 positioned between the intermediate frame 20 and the first cover 28 can be transposed whereby a second pair of side by side recesses for accommodating neutral terminals is defined adjacent to one or other of the phase terminals. <IMAGE>

Description

INSULATING CASE FOR A DIFFERENTIAL CIRCUIT BREAKER WITH PASSING OR DISCONNECTED NEUTRAL The invention relates to an insulating case for a differential circuit breaker with passing or disconnected neutral, comprising - a first compartment housing the neutral circuit, and the differential protection device with toroid associated with a trip relay, - a second compartment housing the phase circuit of the circuit breaker, - an intermediate frame made of insulating material having two opposite open bases, and a separating wall of the first and second adjacent compartments, - a first and second cover designed to be placed on said frame bases, - a first pair of recesses accommodating phase terminals located on the opposite narrow faces facing the second compartment, - and a second pair of recesses accommodating neutral terminals located side by side on the case, facing the first compartment.

The document FR-A 2,627,324 describes a differential circuit breaker with passing neutral, in which the insulating case presents a protruberance to house the neutral terminals, said protruberance being longitudinally offset with respect to the phase circuit compartment. A non-symmetrical case of this kind is designed for a single version of differential circuit breaker, with the direction of the neutral connection imposed.

According to the type of electrical switchboard installation, the neutral can be upstream or downstream. To comply with the specifications of both neutral connection modes, it is then necessary to provide two distinct types of cases, to the detriment of standardization.

The object of the invention consists in achieving a standard insulating case for a differential circuit breaker with independent neutral connection.

The case according to the invention is characterized in that it comprises a first and a second half-flange inserted between one of the bases of the frame and the first cover to form a portion of the opposite narrow faces of the first compartment, the second pair of recesses accommodating the neutral terminals being able to be directed upstream or downstream on the side of one or other of the phase terminals by a corresponding permutation of the two half-flanges.

Depending on whether the electrical switchboard is scheduled for a domestic or industrial installation, the two half-flanges merely have to be permuted to obtain the correct orientation of the neutral terminals. All the components of the case are identical for both the differential circuit breaker versions.

The horizontal edge of the first half-flange comprises a pair of blanking lugs designed to fit in conjugate cut-outs of the frame and of the first cover opposite from the neutral terminals.

The vertical face of the first half-flange is provided with a blind orifice located between two lateral protruberances designed to engage in conjugate recesses of the frame and of the first cover.

The second half-flange is equipped with a pair of cut-outs on the horizontal edge, and a pair of cut-outs on the vertical face, cooperating in abutment respectively with the cut-outs and conjugate recesses of the frame and of the first cover, to form two openings giving access to the tightening screws of the neutral terminals, and two housings to insert the connecting cables in the tunnels of the neutral terminals.

Other advantages and features will become more clearly apparent from the following description of an illustrative embodiment of the invention, given as a non-restrictive example only and represented in the accompanying drawings, in which : - Figure 1 is a schematic elevational view of the differential circuit breaker used for a first neutral connection mode; - Figure 2 represents a profile view of the circuit breaker in figure 1, after the first access cover to the first compartment has been removed; - Figure 3 is an identical view to figure 1, for another neutral connection mode; - Figure 4 shows a profile view of the circuit breaker in figure 3, after the first cover has been removed; - Figures 5 and 6 show elevational views on enlarged scales of a part of the case used for the circuit breakers in figures 1 and 3;; - Figure 7 is a perspective view of the complete case adapted for the connection mode in figure 1; - Figures 8 to 10 show different exploded views of the case according to figure 7, after the second cover has been removed, and in the observation direction indicated by the arrow F1 in figure 5; - Figure 11 is a perspective view (exploded) of figure 6 in the observation direction indicated by the arrow F2, the first cover not being represented.

In figures 1 to 11, a single-pole differential circuit breaker 10 with passing neutral is housed in an insulating case 12 comprising a first compartment 14 housing the neutral circuit and the differential protection device 16, and a second compartment 18 containing the phase circuit of the circuit breaker.

The case 12 comprises an intermediate frame 20 with a reversed H section having two opposite open bases 22, 24, and an insulating middle wall 26 separating the two adjacent compartments 14, 18.

The base 22 cooperates with a first cover 28 with two permutable half-flanges 30, 32 interposed to form the first compartment 14.

The other base 24 of the frame 20 is associated with a second cover 34 (figure 7) to form the second compartment 18.

The first compartment 14 contains a differential transformer with toroid 36 cooperating with a trip relay 38 (figs. 2 and 4) associated with a tripping mechanism 39 of the type described in the document FR-A 2,628,262. A test button 40 enables a differential trip of the circuit breaker 10 to be simulated. The neutral circuit comprises a primary neutral winding wound on the toroid 36 and electrically connected to neutral terminals 42, 44 arranged side by side in recesses of the case 12 (figs. 1 to 4).

The neutral is passing, i.e. the neutral circuit is never broken when the circuit breaker 10 is open.

The second compartment 18 contains the phase circuit of the circuit breaker electrically connected to phase terminals 46, 48 arranged longitudinally in the recesses on the opposite narrow faces of the case 12 (figures 1 and 3). The phase circuit comprises a current interruption circuit with separable contacts, and a manual operating mechanism by a handle 50 and an automatic operating mechanism by a magnetic and thermal trip device. The mechanism is described as an example in the document FR-A 2,616,583.

The phase circuit comprises in addition, a primary phase winding wound on the toroid 36 and electrically connected in series with the trip device by means of connecting conductors passing through two orifices provided in the wall 26 of the frame 20 (see figures 2 and 4).

The two opposite half-flanges 30, 32 form a portion of the narrow side faces of the first compartment 14. The first half-flange 30 comprises a pair of blanking lugs 52, 54 arranged on the opposite flanks of the horizontal edge 55, parallel to the front face, from which the handle 50 protrudes out, and a blind orifice 56, of rectangular section on the vertical face.

The second half-flange 32 is equipped with a pair of opposing semi-circular cut-outs 58, 60 (figs. 8 to 11) on the horizontal edge 62, and a pair of semi-rectangular recesses 64, 66 on the vertical face (fig. 11).

The assembly edges of the frame 20 and first cover 28 cooperate with the two half-flanges 30, 32 by means of cut-outs 68 (figs.

10 and 11) of conjugate shape with the cut-outs 58, 60 and lugs 52, 54, and recesses 70 capable of coming face to face with the recesses 64, 66 of the second half-flange 32 (fig. 11), or of being blanked off by lateral cut-outs 72, 74 located on either side of the orifice 56 of the first half-flange (figs. 8 to 10).

The two opposite faces of the separating wall 26 of the two compartments 14, 18 are provided with assembly spindles 76 or rivets coming from casting with the frame 20, and passing through circular holes 78 arranged in the covers 28, 34 and the two half-flanges 30, 32 of the case 12.

Permutation of the two half-flanges 30, 32 enables two different versions of the differential circuit breaker 10 to be obtained according to the type of electrical switchboard installation.

In a distribution switchboard for industry, the neutral terminals 42, 44 of the differential circuit breaker 10 are located downstream, on the side of the phase terminal 48 (figs.

1, 2 and 7). The first half-flange 30 with blind orifice 56 is then positioned upstream, i.e. on the side of the other phase terminal 46, with the lugs 52, 54 housed in the conjugate cut-outs 68 of the frame 20 and of the first cover 28 to block the access by the horizontal edge 55 (figs. 8 to 10). The blind orifice serves the purpose of inserting an unused tooth of a comb connector, such as is described in French Patent application nO 8,903,278 of 10/3/1989. The protrusions 72, 74 fit into the conjugate recesses 70 of the cover 28 and the frame 20. The second half-flange 32 is downstream, on the side of the phase terminal 48, so that the abutment of the cut-outs 58, 60 and 68 and of the recesses 64, 66, 70 respectively forms two circular openings 80, 82 on the horizontal edge 62 (fig. 5) and two rectangular housings on the vertical edge.The circular openings 80, 82 allow a screwdriver to pass through to access the tightening screws of the two neutral terminals 42, 44. The rectangular housings enable the neutral circuit connecting cables to be inserted in the tunnels of said terminals.

For a domestic distribution switchboard, the two half-flanges 30, 32 merely have to be inverted to direct the neutral terminals 42, 44 upstream on the side of the phase terminal 46, and the orifice 56 downstream on the side of the other phase terminal 48 (figs. 3, 4, 6 and 11).

It can be noted that the orientation of the neutral terminals 42, 44 upstream or downstream is achieved by simply permuting the two half-flanges 30, 32, which enables a standard case 12 to be used for two different versions of a differential circuit breaker 10, and with the same basic components.

The invention also extends to a differential circuit breaker with disconnected neutral.

Claims

1. An insulating case for a differential circuit breaker (10) with passing or disconnected neutral, comprising - a first compartment (14) housing the neutral circuit, and the differential protection device (16) with toroid (36) associated with a trip relay (38), - a second compartment (18) housing the phase circuit of the circuit breaker, - an intermediate frame (20) made of insulating material having two opposite open bases (22, 24), and a separating wall (26) of the first and second adjacent compartments (14, 18), - a first and second cover (28, 34) designed to be placed on said bases (22, 24) of the frame (20), - a first pair of recesses accommodating phase terminals (46, 48) located on the opposite narrow faces facing the second compartment (18), - and a second pair of recesses accommodating neutral terminals (42, 44) located side by side on the case (12) facing the first compartment (14), wherein a first and a second half-flange (30, 32) inserted between one of the bases (22) and the first cover (28) to form a portion of the opposite narrow faces of the first compartment (14), the second pair of recesses accommodating the neutral terminals (42, 44) being able to be directed upstream or downstream on the side of one or other of the phase terminals (46, 48) by a corresponding permutation of the two half-flanges (30, 32).

2. The insulating case for a differential circuit breaker according to claim 1, wherein the horizontal edge (55) of the first half-flange (30) comprises a pair of blanking lugs (52, 54) designed to fit in conjugate cut-outs (68) of the frame (20) and of the first cover (28), opposite the neutral terminals (42, 44).

3. The insulating case for a differential circuit breaker according to claim 2, wherein the vertical face of the first half-flange (30) is provided with a blind orifice (56) located between two lateral protruberances (72, 74) designed to engage in conjugate recesses (70) of the frame (20) and of the first cover (28).

4. The insulating case for a differential circuit breaker according to claim 3, wherein the second half-flange (32) is equipped with a pair of cut-outs (58, 60) on the horizontal edge (62), and a pair of cut-outs (64, 66) on the vertical face, cooperating in abutment respectively with the cut-outs (68) and conjugate recesses (70) of the frame (20) and of the first cover (28) to form two access openings (80, 82) to the tightening screws of the neutral terminals (42, 44), and two housings to insert the connecting cables in the tunnels of the neutral terminals.

5. The insulating case for a differential circuit breaker according to claim 4, wherein each cut-out (58, 60, 68) presents a uniform semi-circular cross-section, and each recess (64, 66, 70) has a semi-rectangular cross-section.

6. The insulating case for a differential circuit breaker according to one of the claims 1 to 5, wherein the two opposite faces of the separating wall (26) are provided with assembly rivets (76) coming from casting with the frame (20), and passing through circular holes (78) provided in the covers (28, 34), and the two half-flanges (30, 32).

7. An insulating case for a differential circuit breaker substantially as hereinbefore described with reference to the accompanying drawings.

8. Any novel feature or combination of features described herein.