EP1724804B1

EP1724804B1 - Reset module for an electrical safety device

Info

Publication number: EP1724804B1
Application number: EP06425295A
Authority: EP
Inventors: Fabrizio Fabrizi; Marcello Re; Flavio Purgato
Original assignee: BTicino SpA
Current assignee: BTicino SpA
Priority date: 2005-05-17
Filing date: 2006-05-03
Publication date: 2010-02-24
Anticipated expiration: 2026-05-03
Also published as: ATE459088T1; EP1724804A3; ITMI20050900A1; EP1724804A2; DE602006012394D1

Abstract

A reset module (200) for an electrical safety device (100) is described having a drive lever to be manually displaced. The reset module comprises a cover that extends to cover the drive lever (112) and prevent any manual contact with the lever. The cover includes an element that engages the drive lever in order to cause, by manually moving the cover from a first to a second position, the switching of the device (100) from the closed to the opened state.

Description

The present invention relates to a reset module for an electrical safety device.
Safety devices (such as, for example, automatic circuit-breakers, ground fault circuit interrupters, automatic ground fault circuit interrupters) fitted in an installation may cause inefficiencies if their action is ill-timed. Tripping is frequent phenomenon, i.e. the ill-timed opening of ground fault interrupters, due to ground leakage currents either resulting from transient surges on the power line (direct or indirect lightning striking) or temporary failure of the insulation.
If the installation place is not guarded, the safety device is not manually closed after it has tripped in a ill-timed manner, thereby severe inefficiency may occur, such as: failure of alarm operation, safety systems, pump systems or switching off of freezers with deterioration of the food contained therein.
These problems have been addressed and partially solved by modules to be associated with the safety devices, which are able to reset and then automatically close the devices at a preset time after tripping. Particularly, a known reset module comprises an inner kinematism acting on the manual lever of the safety device and a thermal actuator acting on the kinematism when the safety device has tripped, in order that the kinematism actuates the resetting.
Patent application EP 0 883 148 describes such a reset device associated with a safety device.
It should be observed that the safety devices provided with the reset module must however allow the manual switching (i.e. the non-automatic opening and closure) of the device.
It has been noticed that conventional reset modules does not allow these manual switching to be carried out in safe. and at the same time, comfortable conditions for the operator that often is not a skilled technician but a user who has only a general knowledge of electrical equipment.
The object of the present invention is to provide a reset module to be associated with the safety device which offers easiness and safety upon carrying out manual switching (particularly, the opening) of the device.
The object of the present invention is achieved by a module such as described in the annexed claim 1. Preferred embodiments of said module are described in the dependent claims 2 to 15. The object of the present invention is also an electrical assembly such as defined in the independent claim 16 having preferred embodiments being defined in claims 17 and 18.
In order to better understand the present invention and appreciate the advantages thereof, some exemplary embodiments thereof will be described below, with reference to the annexed drawings, in which:

Fig. 1 shows a perspective view of a reset module according to an example of the invention, which is assembled to a safety device;
Fig. 2 is a perspective view of an example of said safety device;
Fig. 3 and 4 show a front perspective view of the inside of said reset module comprising a cover in a first and second positions, respectively;
Fig. 5 schematically shows a mechanical coupling mode between the reset module and a drive lever of said safety device;
Fig. 6 and 7 show a side view and a perspective view of a mechanical coupling element used in said reset module, respectively;
Fig. 8 shows, in a rear perspective view, a detail of the inside of said reset module;
Fig. 9 shows a view of said reset module being provided with a door in the opened position.

With reference to the annexed figures, in which similar or identical components are designated with the same numerals, an electrical assembly 300 will be described according to an exemplary embodiment of the invention.
Fig. 1 shows the electrical assembly 300, in the assembled configuration, comprising an electrical safety device 100 and a reset module 200.
The safety device 100 is of a known type and is any circuit breaker suitable to interrupt or establish a current in a circuit by means of suitable contacts that can be separated from each other. These contacts are maintained close to each other with a suitable force when the safety device is in the closed state and are separated by an insulating distance when the device is in an opened state. The safety device 100 can be one of the following circuit breakers: automatic circuit-breaker, ground fault circuit interrupter, automatic ground fault circuit interrupter (such as a magneto-thermal ground fault interrupter).
In Fig. 2 an example of safety device 100 is schematically shown comprising an insulating enclosure body 107, the side walls of which are provided with one or more pair of terminals 109 for the connection of the safety device to matching pairs of electrical wires of an external circuit (not shown in the figures).
The safety device 100 comprises a drive lever 112 (such as a handle) that can be manually displaced between two different positions (indicated by axes 112' and 112"). Particularly, the drive lever 112 can be rotated about an axis 113 for the manual switching of the safety device from the closed state to the opened state, and vice versa. The insulating body 107 houses electromechanical means (not shown, as know per se) therein, which automatically cause the opening of the safety device 100, with the consequent displacement of the drive lever 112, following the detection of a failure, such as a ground leakage current or a short-circuit.
The reset module 200 comprises an insulating enclosure body 201, for example, comprising two portions to be fixed by means of screws that pass through through holes 202. A side of the enclosure 201 is provided with a plurality of terminals 203 for the reset module 200 to be connected to the power line. For example, two input terminals (phase F and neutral N) of the reset module are connected to terminals 109 of the safety device 100. The terminals 203 can be also used to send suitable command signals to the reset module 200, which are transmitted by remote control units, in order to close the safety device 100.
As may be seen in Fig. 3 and 4, the reset module 200 is provided with a rotating bar 204 parallel to the axis of rotation 113 and rear wall of the enclosure 201. In the rotating bar 204 there is formed a longitudinal channel 205, in which the drive lever 112 of the safety device 100 (Fig. 5) can be inserted. The drive lever 112 are slidable within channel 205 in the same direction as the axis 113, such that the electrical assembly 300 can be mounted and such that the drive lever 112 results integral in the rotation with the bar 204. The bar 204, which can be also seen in Fig. 6 and 7, is integral with a rotating body 234 having a substantially cylindrical shape, which is hinged on a pivot 217, of axis 113, from which a first moving rod 218 extends orthogonal to the axis 113.
The reset module 200 comprises automatic actuating means capable of causing the resetting of the device, i.e. causing the same to switch from the opened condition to the closed condition, and optionally causing also the opening thereof. Preferably, these automatic actuating means include a reversible synchronous electric motor 206 (represented with a dotted line in Fig. 3 and partially seen in Fig. 8), which is coupled to the bar 204 by means of a drive mechanism 207. Particularly, a disk 208 is connected to the motor 206 such as to be rotated about a further axis 209 parallel to the axis 113.
A side wall of the disk 208 is provided with recesses, such as three recesses 210-213 being arranged such as to form 120° angles in the middle of the disk 208. In the vicinity of the disk 208 there is arranged a first microswitch 214 having a leaf spring 215 (or other equivalent elastic means) associated therewith, which ends with an idle wheel 216 that is free to rotate about an axis parallel to the further axis 209. This first microswitch 214 acts as a limit switch and opens thus interrupting the power supply to the motor 206 and, accordingly, the rotation of the disk 208 when the idle wheel 216 is within one of the recesses 210-213.
According to the exemplary embodiment of the invention as represented in the figures, the disk 208 is mechanically coupled with the first rod 218 by means of a plurality of relieves, such as three relieves 219-221 (the reference numbers of these relieves have been designated, for clarity, only in Fig. 4). During the rotation of the disk 208, the relieves 219-221 are suitable to engage the first rod 218, which extends above the disk 208 only when it is in the position corresponding to the opened state of the device 100, thereby causing the bar 204 to rotate in the opposite direction relative to the rotation of the disk.
The container 201 of the reset module 200 is also provided with a second microswitch 222 (shown in Fig. 7 and Fig. 8) having a respective leaf spring 223 intended to be biased by a second rod 224 that is integral with the rotating body 234 and such as to extend, in the example illustrated, parallel to the axis 113 in the opposite direction to that of the bar 204. The second microswitch 222 is sensitive to the "tripped" condition of the safety device 100 and allows the activation of the motor 206 and, thus, the resetting of the safety device only after the bar 204 has moved to the opened state condition.
The reset module 200 is further equipped with a cover 225 coupled with the enclosure 201 such as to be manually moved relative to the enclosure. Particularly, the cover 225 is coupled with the respective enclosure by means of guide means allowing the cover to slide (preferably, along an axis orthogonal to axis 113) between a first position 1P and a second position 2P.
In the first position 1P (illustrated in Fig. 3), the cover 225 is aligned with a side wall 226 of the enclosure 201. Depending on the particular operating condition, in the first position 1P, the bar 204 can be in the "lowered" position corresponding to the open state (such as in the particular case of Fig. 3), or it can be in a "raised" position, corresponding to the closed state of the safety device 100.
In the second position 2P (Fig. 4), the cover 225 is misaligned relative to the side wall 226 of the enclosure 201. As will be explained below, when the cover is in the second position 2P, the bar 204 can be only in the "lowered" position (as illustrated in Fig. 4), corresponding to the opened state of the safety device 100. To cause the sliding movement between the first and second positions and vice versa, the cover 225 can be manually gripped and advantageously has an ergonomic recess 227 that facilitates this manual operation.
The cover 225, which is made of an electrically insulating material, comprises a front wall 228 (Fig. 1), an upper wall 229, a lower wall 230, and an outer side wall 230' and an inner side wall 229' (illustrated in Fig. 3 and 4). Furthermore, this cover extends past the enclosure 201 such that, when the reset module 200 is assembled to the safety device 100, it covers the drive lever 112 thus protecting the latter and preventing any manual contact therewith.
The cover 225 is such as to engage the bar 204 (and thus the drive lever 112) such as to cause, by sliding from the first 1P to the second 2P position, the rotation of the bar 204 (and the drive lever 112) with consequent switching of the safety device from the closed to the opened state. Particularly, to the purpose, the cover 225 is provided with an engaging element 231 extending inside the cover to abut against the bar 204 and cause the rotation thereof, together with the drive lever 112. According to the example of Fig. 3 and 4 this abutment element 231 is embodied by a projection provided inside the upper side wall 229 such as to pull the bar 204 (at least to half the travel thereof) during the sliding of the cover 225.
Advantageously, the cover 225 comprises a door to be opened/closed 232 (Fig. 1 and Fig. 9) which allows access to the bar and particularly to a handle 242 (Fig. 6 and Fig. 9) integral with the bar, in order to rotate the same and bring the safety device 100 from the opened to the closed state, when the cover is in the first position 1P.
Preferably, the reset module 200 includes locking means that inhibit the raising of the bar 204 and thus the closure of the safety device 100, when the cover 225 is in the second position 2P of Fig. 4. Particularly, these locking means are associated with the cover 225 and are embodied by a projection 233 (seen in Fig. 3 and 4) protruding from the inner side wall 229' such as to be inserted in an aperture 235 (indicated with the numeral reference only in Fig. 7) being formed in the rotating body 234. When the cover 225 is caused to slide from the first 1P to the second 2P position, the projection 233 is inserted in the slot 235 of the rotating body 234, thereby the rotation of the bar in the opposite direction is inhibited. If the cover 225 is moved from the second position back to the first position, the projection 233 is then disengaged from the slot 235 and the bar 204 can be rotated to close the safety device.
Advantageously, the reset module 200 is provided with a reset deactivation device such that, when the cover 225 has been displaced by moving the safety device from the closed to the opened state, the automatic resetting is inhibited, which would close the safety device. Preferably, this deactivation device is a conventional circuit-breaker (not shown) having contacts that can be opened and closed when the cover 225 slides from a suitable portion of the cover 225.
It should be observed that, for clarity purposes, the electrical wires of the synchronous motor 206 and the wires connecting the first microswitch 214 to the second microswitch 222, or the reset deactivation device as discussed above have not been shown in the figures. The electrical connections of these circuit-breakers appear from the above description of their operation.
With reference to the mounting of assembly 300, the reset module 200 (which may have, for example, a size equal to two DIN modules) is structurally coupled with the safety device 100 in a manner known per se, and for example, by means of clips 250 (Fig. 2) to be inserted in apertures 172 provided in the enclosure body 107 of the safety device 100. These clips 250 are fixed to a respective L-shaped element 251 to be inserted in a seat (not shown) that is formed on the side wall of the enclosure 201 and to be fixed thereto by means of a screw 253 (Fig. 2). Advantageously, the cover 225 can be adapted such as to extend and cover the front surface of the safety device 100, whatever the standardized width of the devices. To the purpose, additional covering elements (not shown) are provided to be (removably) fittingly fixed (and preferably with screws) to the outer side wall 230' of the cover 225 to increase the size thereof.
Furthermore, as illustrated in Fig. 8, the cover 225 can be provided with a through hole 255 for a padlock to be applied in the second position 2P, such that unauthorized users are prevented from causing the cover 225 to slide to the first position 1P.
With reference to the operation of the reset module 200 being mounted to the safety device 100, the operating steps are as follows: automatic opening, automatic closure, manual opening and manual closure.
In the automatic opening, starting from the safety device 100 being in the closed condition an event may occur (leakage current or a short-circuit) causing the opening thereof. In this case, the drive lever 112 rotates and pulls the bar 204 therewith thereby causing the body 234 to rotate. The cover 225 remains in the first position 1P of Fig. 3, but the rotation of the body 234 integral with the second rod 224 causes the switching of the second microswitch 222, which can allow the power supply to the synchronous motor 206 by means of a possible external circuit, in order to operate the motor 206 to close.
As a further consequence of the opening of the safety device 100, the second microswitch 222 can also generate an "open state" signal provided on one of the terminals 203 in order to signal to a remote unit that the safety device has been opened. Furthermore, it should be noted that, in the opened state, the ON/OFF indication which is normally written on the drive lever of the safety devices, is not seen because it is hidden by the (opaque) cover.
For example, the reset module 200 may be provided with a window 241 (Fig. 1) from which one of two alternative indications I-ON and I-OFF can be seen. The indication I-ON, seen through the window 241 following an automatic opening, indicates that the reset module is in the active state.
For the automatic closure of the safety device, subsequent to the automatic opening thereof, the synchronous motor 206 (powered by means of an external circuit by means of the second microswitch 222 of Fig. 8) causes the disk 208 to rotate (for example, in the counter-clockwise direction, with reference to Fig. 3). The rotation of the disk 208 causes one of the relieves 219-222 to act on the first rod 218 thereby causing the bar 204 and the first drive lever 112 to rotate such that the safety device is moved to the closed state. The first microswitch 214 of Fig. 3 and 4 is opened, after one-third of revolution, the power supply to the motor 206 being thus interrupted.
With reference to the manual opening, the safety device 100 has to be considered as being in the closed state. The manual opening can be carried out by directly acting on the cover 225 (particularly, on recess 227), which is caused to slide and brought from position 1P to 2P. During this step, the abutment element 231 acts on the bar 204 causing the same to rotate, and the consequent opening of the safety device 100. It should be noted that the Fig. 3 relates to a condition in which the cover 225 is caused to slide after an automatic opening has occurred and thus the element 231 does not appear abutted against the bar 204.
Advantageously, by moving the cover 225 to the second position 2P, due to the projection 233 being inserted in the slot 235 of the body 234, a blockage of the bar 204 is caused, which bar cannot be rotated to close the safety device 100. Furthermore, advantageously, during the sliding movement of the cover 225, the contact of the deactivation circuit-breaker opens, thus interrupting the power supply to the motor 206, in order to inhibit the automatic resetting. For example, in the second position following the manual opening, the window 241 will indicate the wording I-OFF to indicate the opened condition but also that the resetting, either manual or automatic, is inhibited. The wordings I-ON and I-OFF are reported, for example, on a suitable portion of the cover 225 which slides below the windows 241.
Following a manual opening, an automatic closure can be carried out, which is provided by simple manoeuvres. First, the cover 225 must be brought back to the first position 1P by causing the projection 233 to be disengaged from the slot 235 of the body 234. Then, the door 232 is opened (for example, manually) such as to gain access to the handle 242 which is then manually rotated to close the safety device 100. The door 232 can be advantageously provided with an elastic element or other means causing the same to close again. When the cover 225 has been brought to the first position 1P, an automatic closure by means of a command signal that activates the motor 206 is also possible.
The teachings of the present invention are particularly advantageous. In fact, it should be noted that the manual opening of the device 100 associated with the reset module 200 is particularly advantageous, since it can take place with a single manoeuvre (i.e. by acting only on cover 225 without having to remove the same to gain access to the lever 112) and in total safety, since the cover is made of an insulating material and the drive lever 112 is not accessible. Furthermore, as the mechanical lock of the bar 204, when the cover is in the second position 2P, can be removed only by bringing the cover 225 to the first position 1P, this prevents any inadvertent manual resetting. The inhibition of the resetting, due to the deactivation circuit-breaker, when the cover is moved to the second position 2P also contributes to the safety of the inventive electrical assembly. The fact that the signalling of the opened state (I-OFF, at window 232) is provided only when it is ensured that the automatic resetting is inhibited makes the inventive assembly particularly safe.
Another advantage of the reset module described by way of example is that it employs a synchronous motor which ensures the resetting after a few seconds from opening, thereby being much faster than the known module, which uses a thermal actuator before activating the resetting.
Obviously, to the electrical assembly according to the present invention, those skilled in the art, aiming at satisfying contingent and specific requirements, may carry out a number of modifications and variations, all being however contemplated within the scope of protection of the invention, such as defined in the annexed claims.

Claims

A reset module (200) for an electrical safety device (100) having a drive lever (112) to be manually displaced, the module comprising:
- automatic actuating means (206) housed in an enclosure (201) that can be associated to the device in order to switch the latter from an opened state to a closed state,
mechanical coupling means (208, 218, 234, 204) which are operatively associated with the actuating means (206) and drive lever (112) to allow the switching between the opened and closed state, said opened and closed states corresponding to respective positions of the drive lever.

- a cover (225) to be coupled to the container in a manually movable manner,
characterized in that the cover extends from the enclosure (201) to cover the drive lever (112) and prevent manual contact therewith and is such as to be engaged with the coupling means or drive lever such as to cause the switching of the device (100) from the closed to the opened state by manually moving the cover from a first (1P) to a second (2P) position.
The module (200) according to claim 1, wherein said cover (225) comprises:
- guide means for slidingly coupling the cover with the enclosure such that the cover can be caused to slide between the first (1P) and second (2P) positions,

- at least one portion (227, 229) to be manually gripped to impose the sliding between the first and second positions and vice versa,

- an engaging element (231) extending inside the cover to abut against at least a part of said mechanical coupling means (204) and causing the displacement of the drive lever (112) and the switching from the closed to the opened state consequently to the cover sliding from the first (1P) to the second (2P) position.
The module (200) according to claim 1, wherein the enclosure (201) and cover (225) are made of an electrically insulating material.
The module (200) according to claim 1 or 2, wherein the drive lever (112) of the device can be rotated about an axis (113) between two operative positions corresponding to the closed state and opened state, said mechanical coupling means comprising a rotating bar (204) connected to the automatic actuating means (206), which is parallel to said axis of rotation, and provided with a longitudinal channel (205) in which the drive lever (112) can be inserted.
The module (220) according to claim 4, wherein the cover (225) slides orthogonal to said axis of rotation (113).
The module (200) according to claims 2 and 4, wherein the engaging element (231) is such as to act on the bar (204) thus causing the bar and drive lever to rotate.
The module (200) according to claim 1, comprising a device for deactivating the automatic actuating means such that, when the cover has been moved from the first to the second position, by bringing the device to the opened state, the automatic resetting is inhibited, which would bring the device from the opened to the closed state.
The module (200) according to claim 1 or 7, wherein said cover comprises a door (232) to be opened to gain access to the mechanical connection means and activate them manually in order to perform a manual resetting of the device by bringing the latter from the opened state to the closed state.
The module (200) according to claim 8, further including locking means (233) of the mechanical coupling means to inhibit the manual activation of the same when the device (100) has been brought from the closed to the opened state by manually moving the cover from the first to the second position; the manual switching from the closed to the opened state being allowed by the locking means only after the cover has been moved from the second to the first position.
The module (200) according to claim 4, wherein said coupling means further include a body (234) integral with said bar (204), which is intended to be rotated by the actuating means (206).
The module (200) according to claims 9 and 10, wherein the locking means comprise a projection (233) integral with said cover (225) which is intended to be inserted in an aperture (235) of the rotating body (234) in order to inhibit the rotation of the same, during the movement of the cover from the first to the second position.
The module (200) according to claim 1, wherein said automatic actuating means include a synchronous motor.
The module (200) according to claims 10 and 12, wherein the mechanical coupling means include:
- a disk (208) intended to be operated by the motor (206) and provided with a plurality of relieves (219-221),

- a rod (218) integral with said rotating body (234) and such as to rotate the rotating body when it is engaged with one of the relieves provided on the rotating disk.
The module (200) according to claim 13, further comprising a first microswitch (214) to be operatively associated with said disk (208) and intended to interrupt the power supply to the motor (206) following a rotation of the disk (208) such as to cause the switching from the opened to the closed state.
The module (200) according to claim 13, further comprising a second microswitch (222) which is operatively associated with said rotating body (234) and such as to inhibit the power supply to the motor (206) following a first displacement of the cover (225) from the first (1P) to the second (2P) position.
An electrical assembly (300) comprising a safety device (100) associated with a reset module (200) of said device, characterized in that said reset module is provided according to at least one of the preceding claims.
The electrical assembly (300) according to claim 16, wherein said safety device is one of the following devices: automatic circuit-breaker, ground fault circuit interrupter, automatic ground fault circuit interrupter.
The electrical assembly (300) according to claim 16, wherein said resetting module is housed in an enclosure (201) separated from a further enclosure (107) that houses the safety device; the assembly comprising means (250, 251, 253) for fixing the reset module to the safety device.