Abstract:
A device for protecting an electrical installation including an insulating body electrically defining an internal housing, the protective device including, within the internal housing: an active component of a device for protecting an electrical installation; a disconnection system for disconnecting the active component moveable between a contact position corresponding to a connected state of the active component and an open position corresponding to a disconnected state of the active component; a disconnection indicator, where the disconnection indicator is secured in movement to the disconnection system and the disconnection indicator and the insulating body are arranged to have a first configuration, which corresponds to the contact position, and a second configuration, which corresponds to the open position, the relative positioning of the disconnection indicator with respect to the insulating body in the first configuration being visually distinct from the outside of the insulating body from the relative positioning of the disconnection indicator with respect to the insulating body in the second configuration.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is related to and claims the benefit of European Patent Application Number 14/55681 filed on 20 Jun. 2014, the contents of which are herein incorporated by reference in their entirety. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to a device for protecting an electrical installation comprising a system for disconnecting an active component of the device with visual indicator. 
       BACKGROUND 
       [0003]    A varistor is an active component of a device for protecting an electrical installation, such as a lightning arrester. Current varistors, or variable resistors comprise a ceramic block for example composed of zinc oxide assembled by sintering and have a non-linear current/voltage characteristic: beyond a certain voltage threshold, the varistor impedance drops to allow the discharge of current following a voltage surge. When the voltage returns to its normal level, the varistor impedance assumes its value at the standby state. 
         [0004]    In a lightning arrester, one or several varistors are generally disposed in a cartridge also comprising a connection element, allowing to electrically connect them to the electrical installation to be protected. 
         [0005]    In order to prevent damage due to malfunctions and to abnormal heating phenomena of the varistors, the latter must be fitted with a disconnection system. This leads for a need to equip lightening arresters with systems for indicating a connected or disconnected state of the varistors. 
         [0006]    It is known to use indication systems comprising electrical lights mounted in parallel on the varistors. The use of electrical lights leads to permanent energy consumption. 
         [0007]    It is also known to use mechanical indication systems requiring the use of several expensive and bulky pieces which lead to a blocking risk of the mechanism. 
       BRIEF SUMMARY 
       [0008]    The disclosure resolves all or part of the aforementioned drawbacks. 
         [0009]    To this end, the present disclosure relates to a device for protecting an electrical installation comprising an insulating body electrically defining an internal housing, the protective device comprising a first joining element and a second joining element intended for joining the protective device to the electrical installation, and comprising, within the internal housing:
       a first portion of the electrical circuit connected to the first joining element and a second portion of the electrical circuit connected the second joining element;   a varistor comprising a first terminal electrically connected to the first portion of the electrical circuit and a second terminal;   a disconnection system for disconnecting the varistor comprising a connection element arranged for electrically connecting the second terminal of the varistor to the second portion of the electrical circuit, the connection element comprising a moveable part capable of occupying a contact position in which the connection element is electrically connected to the second terminal of the varistor, and an open position in which the connection element is electrically insulated from the second terminal of the varistor;   a disconnection indicator;   characterized in that the disconnection indicator is secured in movement to the moveable part of the connection element, and in that the disconnection indicator and the insulating body are arranged to have a first configuration, which corresponds to the contact position of the moveable part of the connection element, and a second configuration, which corresponds to the open position of the moveable part of the connection element, the relative positioning of the disconnection indicator with respect to the insulating body in the first configuration being visually distinct from the outside of the insulating body from the relative positioning of the disconnection indicator with respect to the insulating body in the second configuration.       
 
         [0015]    According to one aspect of the invention, there is no relative movement between the disconnection indicator and the moveable part of the connection element. 
         [0016]    Thanks to the dispositions according to the invention, the indicator of the connected or disconnected state of the active component is integrated to the disconnection system and thus has a limited size. In addition, no friction is caused by the passage of the moveable part of the connection element, and hence of the disconnection indicator, from the contact position to the closed position. Thus, the wear of the materials as well as the risks of blocking due to this movement are limited. Finally, this type of indicator does not cause any additional energy consumption. 
         [0017]    According to optional features of the device for protecting an electrical installation:
       the protective device comprises an electrically insulating mounting portion comprising a reception housing for receiving the connection element and secured in movement to the connection element;   the mounting portion comprises a moveable part arranged for accommodating the moveable part of the connection element;   the disconnection indicator is formed of a single piece with the mounting portion, the disconnection indicator is thus secured to the mounting portion, and is hence secured in movement to the connection element;   the connection element is deformable;   the mounting portion is deformable;   a return element allows the passage of the moveable part of the connection element from the contact position to the open position;   the return element is a spring;   in the contact position, the moveable part of the connection element is mechanically fixed to the second terminal of the varistor;   the mechanical fixing of the moveable part of the connection element to the second terminal of the varistor is ensured by brazing a retaining element;   the retaining element can melt from a threshold temperature, the threshold temperature corresponds to a temperature of abnormal heating of the varistor;   when the varistor reaches the threshold temperature, the retaining element melts and the return element moves the moveable part the connection element from the contact position to the open position;   the insulating body comprises a viewing portion disposed facing the disconnection indicator, allowing the operator to know the position of the moveable part of the connection element;   the disconnection indicator comprises a first portion visible from the outside of the insulating body in the first configuration and a second portion visible from the outside of the insulating body in the second configuration, the first portion and the second portion being visually distinct;   the first portion and the second portion of the disconnection indicator have different colors, allowing the operator to distinguish between the contact position and the open position;   the first portion of the disconnection indicator is at the viewing portion in the first configuration and the second portion of the disconnection indicator is at the viewing portion in the second configuration;   the viewing portion is an opening in the insulating body;   the viewing portion is a transparent portion of the insulating body;   the connection element is electrically connected to the second portion of the electrical circuit;   the connection element comprises a stationary part at which it is connected to the second portion of the electrical circuit;   the insulating body comprises a rear face intended to be mounted on a support and a front face, opposite the rear face, the front and rear faces defining an internal housing along the first extension direction;   the varistor and the disconnection system being disposed in the internal housing of the insulating body, aligned along a second extension direction of the internal housing, transverse to the first extension direction, a transverse extension direction meaning, an extension direction oriented according to an angle between 60° and 120° with respect to the first extension direction;   preferably, the second extension direction is oriented according to an angle between 70° and 110° with respect to the first extension direction;   preferably, the second extension direction is oriented according to an angle between 80° and 100° with respect to the first extension direction;   preferably, the second extension direction is oriented perpendicularly to the first extension direction;   the varistor and the disconnection system are disposed in the internal housing of the insulating body aligned along the second extension direction;   a face of the insulating body delimits the insulating body in the second extension direction and is intended to form a lower face of the protective device when the latter is disposed on a substantially vertical support, in such a manner that the second extension direction be substantially vertical;   the first portion of the electrical circuit and the second portion of the electrical circuit extend along the second extension direction in the internal housing of the insulating body;   the first portion of the electrical circuit and the second portion of the electrical circuit extend facing the rear face of the insulating body;   the lower face comprises a first opening in which the first joining element is capable of being inserted, and a second opening in which the second joining element is capable of being inserted;   the insulating body comprises a solid upper face, opposite the lower face;   the insulating body comprises two solid lateral faces, opposite to one another;   the insulating body is substantially parallelepiped;   the insulating body is formed of two half shells brought onto one on another;   a contact zone of the half shells sealingly crosses the upper face;   the first and second joining elements are adjacent to one another;   the first and second joining element correspond, indifferently to the phase and the neutral;   the first and second conductive elements are conductive wires with screws;   the first and the second conductive elements are output terminals with screws;   the protective device comprises a third joining elements;   the third joining elements corresponds to neutral;   the third joining elements comprises a conductive element;   the conductive element is a conductive wire with screws;   the conductive element is an output terminal with screws;   the lower face of the insulating body comprises a third opening in which the third joining elements can be inserted;   the first, second and third joining elements are disposed on a same face of the insulating body;   the varistor comprises a first electrical joining lug, a second electrical joining lug and an active body comprising a first face and a second face;   the first face and the second face of the varistor are opposite each other;   the first and the second joining lugs each comprise a conductive path electrically connected to the active body the varistor;   the first connecting lug comprises a first portion extending facing the first face of the active body and a second portion electrically connected to the first portion of the electrical circuit;   the second joining lug comprises a first portion extending facing the second face of the active body, electrically connected to the connection element electrically connected to the second portion of the electrical circuit, and a second portion at a distance from the first portion and second portion of electrical circuit;   the device comprises an electrically insulating mounting element comprising the mounting portion comprising a housing for receiving the connection element and a second mounting portion comprising a housing for receiving the varistor;   the second mounting portion is formed of a same piece with the mounting portion comprising a housing for receiving the connection element;   the return element is disposed between the mounting portion accommodating the connection element and the second mounting portion;   the second mounting portion comprises a housing for receiving the second portion of the second connecting lug;   the active body of the varistor, the first joining lug and the second connecting lug are covered with an electrically insulating coating;   the insulating coating comprises a first opening at the second portion of the first joining lug, and a second opening at the second portion of the second joining lug;   the second portion of the first joining lug is electrically connected to the first portion of the electrical circuit at the first opening, which constitutes the first terminal of the varistor;   the second portion of the first joining lug extends along the first extension direction;   the second portion of the second joining lug extends along the second extension direction, transverse to the first extension direction;   the coating comprises a third opening at the first portion of the second joining lug;   the first portion of the second joining lug is connected to the disconnection system at the third opening, which constitutes the second terminal of the varistor;   the second portion of the first joining lug extends along the first extension direction;   the second portion of the second joining lug extends along the second extension direction.       
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0081]    Other features and advantages of the present invention will become apparent in light of the following description and by examining the accompanying figures, in which: 
           [0082]      FIG. 1  represents a device for protecting an electrical installation in a cutaway view; 
           [0083]      FIG. 2  represents the elements disposed in the internal housing of the insulating body; 
           [0084]      FIG. 3  represents a varistor and a disconnection system in the contact position; 
           [0085]      FIG. 4  represents a varistor and a disconnection system in the open position. 
       
    
    
       [0086]    On all these figures, identical or similar references designate identical or similar members or assemblies of members. 
       DETAILED DESCRIPTION 
       [0087]      FIG. 1  represents a device  1  for protecting an electrical installation intended to be added onto a support (not represented), for example a DIN type rail, within an electrical box along a substantially vertical direction. The protective device  1  comprises an electrically insulating body  3 , substantially parallelepiped. The insulating body  3  comprises a rear face  3   a  intended to be fixed onto the support. The insulating body  3  further comprises a front face  3   b  opposite the rear face  3   a,  visually accessible when the device is added onto the support. The front  3   b  and rear  3   a  faces define an internal housing  5  along an extension direction D 1 . The insulating body comprises a face  3   c,  destined to be the lower face of the insulating body  3  when the protective device  1  is added onto the support, that is to say, during operation. A face  3   d,  solid and opposite the face  3   c  is intended to be the upper face of the insulating body  3  when the protective device  1  is added onto the support. The faces  3   c  and  3   d  define a second extension direction D 2 . The second extension direction D 2  is substantially perpendicular to the first extension direction D 1 . The insulating body  3  further comprises faces  3   e,  solid and opposite to one another. 
         [0088]    As represented in  FIG. 2 , the internal housing  5  comprises a printed circuit  7  including two portions of electrical circuit or conductive paths  7   a,    7   b,  represented on  FIGS. 3 and 4 . The internal housing  5  further comprises an active component, here a varistor electrically connected to a disconnection system  11 . A first conductive path  7   a  is electrically connected to the varistor  9  and a second conductive path  7   b  is electrically connected to the disconnection system  11 . The conductive paths  7   a,    7   b  are each further electrically connected to a joining element  13   a,    13   b  and  13   c  of the protective device  1  to the main circuit of the electrical installation to be protected. 
         [0089]    The internal housing  5  here comprises, a second varistor  9 ′ coupled to a second disconnection system (not represented), having a disposition and operation identical to the varistor  9  coupled to the disconnection system  11 . 
         [0090]    The varistor  9  and the disconnection system  11  are disposed in an aligned manner in the internal housing  5  along the second extension direction D 2  of the internal housing  5 . The printed circuit  7  is oriented along the second extension direction D 2 . The printed circuit  7  runs along the length of the varistor  9  and the disconnection system  11 . Thus, the connection of the varistor  9  and disconnection system  11  to the conductive paths  7   a,    7   b  is facilitated. 
         [0091]    The joining elements  13   a,    13   b  are adjacent to one another. The face  3   c  comprises a first insertion opening  15   a  in which the joining element  13   a  is suitable to be inserted. The joining element  13   a  comprises a conductive element, here a conductive wire with screws  16   a.  The face  3   c  further comprises a second insertion opening  15   b  in which the joining element  13   b  is suitable to be inserted. The joining element  13   b  comprises a conductive element, here a conductive wire with screws  16   b.  The conductive wires  16   a  and  16   b  are attached to the phase and the neutral. The face  3   c  further comprises an opening  15   c,  in which the joining element  13   c  is suitable to be inserted here having the shape of an output terminal with screws, attached to the ground. The conductive wires  16   a  and  16   b , and the output terminal are then joined to the printed circuit  3 . The connecting of the conductive wires  16   a  and  16   b  and the output terminal is, for example, achieved by welding on the printed circuit  3 , at the conductive paths. 
         [0092]    These insertion openings  15   a,    15   b  are disposed on the face  3   c  of the insulating body  3 . 
         [0093]    The insulating body  3  comprises two half shells added onto each other at a contact zone. The contact zone sealingly crosses the face  3   d.  Thus, in case of bad weather or condensation, water mainly flows on the upper  3   d  and lateral  3   a,    3   b,    3   e  faces of the insulating body  3 . The risk of water infiltrating inside the protective device  1  is thus reduced. 
         [0094]    The internal housing  5  of the insulating body  3  further comprises an electrically insulating mounting element  17  including a first mounting portion  17   a  and a second mounting portion  17   b,  formed of a same piece. The first mounting portion  17   a  comprises a reception housing  19  arranged for accommodating the varistor  9 . The second mounting portion  17   b  comprises a reception housing  21  arranged for accommodating the disconnection system  11 . The mounting element  17  thus allows the insulation of the varistor  9 , the disconnection system  11  and the printed circuit  7  with respect to one another. It is thus possible to bring these elements closer to one another without risking unwanted electrical connection. This arrangement of elements within the internal housing  5  of the insulating body  3  thus allows reducing the size of the protective device  1 . 
         [0095]    As it is also represented in  FIGS. 3 and 4 , the varistor  9  comprises an active body comprising a ceramic block, here having the shape of a pellet  23 . The varistor  9  further comprises a first joining lug  25  and a second joining lug  27 , electrically connected to the pellet  23 . The pellet  23  comprises a first main face  23   a  and a second main face  23   b,  opposite to the first main face  23   a . The connecting lugs  25 ,  27  each comprise a portion extending facing one of the main faces of the pellet  23 . For example, the connecting lug  27  comprises a portion  27   a  disposed facing the second main face  23   b  of the pellet  23 . The pellet  23  and the connecting lugs  25 ,  27  are covered with an insulating coating. The connecting lug  25  comprises an end portion  25   b  and the connecting lug  27  comprises an end portion  27   b.  The insulating coating comprises a first opening  29  at the end portion  25   b  of the connecting lug  25 . The insulating coating comprises a second opening  31  at the end portion  27   b  of the connecting lug  27 . The end portions  25   b  and  27   b  hence each comprise a conductive portion at the openings  29 ,  31  respectively. 
         [0096]    The conductive portion of the connecting lug  25  constitutes a first terminal  9   a  of the varistor  9 , which allows connecting the varistor  9  to the first conductive path of the printed circuit  7 . The end portion  25   b  extends along the extension direction D 1  and is substantially perpendicular to the printed circuit  7 , extending along the extension direction D 2 . 
         [0097]    The conductive portion of the connecting lug  27  is located at a distance from the printed circuit  7  and is hence directly isolated from the latter. The end portion  27   b  extends along the direction D 2 , it is thus substantially perpendicular to the end portion  12   b  and substantially parallel to the printed circuit  7 . The end portion  27   b  is disposed in a housing  33  for receiving the first mounting portion  17   a.    
         [0098]    On the second main face  23   b  of the pellet  23 , the insulating coating comprises a third opening  35  at the portion  27   a  of the connecting lug  27 . The portion  27   a  thus comprises a conductive portion at the opening  35 . The conductive portion constitutes a second terminal  9   b  of the varistor  9  by which the varistor  9  can be electrically connected to the disconnection system  11 . 
         [0099]    These dispositions allow for example using standard varistors, from a store. 
         [0100]    The disconnection device  11  comprises a connection element, here constituted by a conductive wire  37 . According to another embodiment of the invention, the connection element may for example be constituted of a thin conductive blade. The conductive wire  37  comprises a stationary part  39   a  at which it is electrically connected to the second conductive path  7   b  of the printed circuit  7 . The conductive wire  37  is hence able to electrically connect said second terminal  9   b  of the varistor  9  to the printed circuit  7 . A portion  37   a  of the conductive wire  37  is covered by a protective insulating coating. The conductive wire  37  comprises a moveable portion  39   b.  The second mounting portion  17   b  comprises a housing for receiving the conductive wire  37 . The second mounting portion  17   b  is secured in movement to the thread  37  and comprises a moveable part  41 , accommodating the moveable part  39   b  of the conductive wire  37 . The moveable parts  39   b ,  41  of the conductive wire  37  and the second mounting portion  17   b  are deformable between a contact position and an open position. The friction phenomena due to the passage of the moveable parts  39   b,    41  the conductive wire  37  and of the second mounting portion  17   b  from the contact position to the open position are hence limited. 
         [0101]    An elastic return element, here a spring  43  is disposed between the second mounting portion  17   b  and the first mounting portion  17   a  and is capable of moving the moveable parts  39   b,    41  of the conductive wire  37  and of the second mounting portion  17   b.    
         [0102]    A disconnection indicator  45  is formed of a single piece with the mounting element  17 . The disconnection indicator  45  is located at the moveable part  41  of the second mounting portion  17   b.  The disconnection indicator  45  is thus also moveable between the contact position and the open position. The disconnection indicator  45  comprises two visually distinct portions: a first uncolored portion  45   a  and a second colored portion  45   b.    
         [0103]    The insulating body  3  comprises a viewing portion at its front face  3   a,  here an opening  47  allowing to view from the outside, one of the portions  45   a,    45   b  of the disconnection indicator  45  facing the opening  47 . 
         [0104]    In the contact position represented in  FIGS. 1 ,  2  and  3 , the conductive wire  37  is electrically connected to the second terminal  9   b  of the varistor  9 . The spring  43  is compressed and exerts a stress in a direction indicated by the arrow  49 . In order to maintain the position of the moveable parts  39   b,    41  of the conductive wire  37  and of the second mounting portion  17   b,  a retaining element allows fixing an end portion  37   b  of the conductive wire  37  to the second terminal  9   b  of the varistor  9 . The retaining element is a solder. The solder is selected from a material capable of melting from a threshold temperature, corresponding to an abnormal overheating temperature of the varistor  9 . As represented on  FIG. 1 , in contact position, the uncolored portion  45   a  of the disconnection indicator  45  is located at the opening  47  of the insulating body  3 . This uncolored portion  45   a  is visible from the outside of the insulating body  3  and indicates to an operator the connected state of the varistor  9 . 
         [0105]    In an open position, represented on  FIG. 4 , the conductive wire  37  is isolated from the second terminal  9   b  of the varistor  9 . The spring  43  is released. The solder is melted. In this position, the colored portion  45   b  of the disconnection indicator  45  is located at the opening  47  of the insulating body  3 . The colored portion  45   b  is visible from the outside of the insulating body  3  and indicates to an operator the disconnected state of the varistor  9 . 
         [0106]    During an abnormal heating of the varistor  9 , the intrinsic temperature of the varistor  9  reaches a temperature that is higher than or equal to the threshold temperature from which the solder is capable of melting. Thus, the solder melts, the spring  43  is released and allows a displacement along the direction  49  of the moveable parts  39   b,    41  of the conductive wire  37  and the second mounting portion  17   b,  as well as the disconnection indicator  45 . The colored portion  45   b  of the disconnection indicator  45  is hence located at the opening  47  of the insulating body  3 . 
         [0107]    The second varistor  9 ′ identically cooperates with identical elements. Obviously, the present invention is not limited to the described and represented embodiment, provided by way of illustrating and non-limiting example. 
         [0108]    According to one embodiment, the disconnection indicator  45  could be independent from the second mounting portion  17   b  while remaining secured in movement to the moveable part  39   b  of the conductive wire  37 . 
         [0109]    According to one embodiment, the viewing portion of the insulating body  3  may be constituted by a transparent portion, thus revealing the disconnection indicator  45  from the outside, and ensuring the sealing of device. 
         [0110]    According to one embodiment, the joining elements may comprise output terminals with screws for the phase, the neutral and the ground. 
         [0111]    According to one embodiment, the joining elements may comprise conductive output wires with screws for the phase, the neutral and the ground.