FR2704064A1 - Electric-current meter - Google Patents

Abstract

An electric-current meter intended to be installed on an electrical panel is composed of a plurality of electrical appliances, each of which delivers to a load, via electrical power cables, an electric current, the strength of which may be measured by the said electric-current meter, each electrical appliance including, on a side face, output connection contacts. According to the invention, the electric-current meter (1) comprises, on one side face, input connection contacts (8) and, on an opposite side face (10A), output connection contacts (3), said input connection contacts (8) being connected to said respective output connection contacts of one of the said electrical appliances and the said output connection contacts (3) being connected to the said electrical power cables.

Description

ELECTRIC CURRENT MEASURING BLOCK
The present invention relates generally to an electrical current measurement block.

 In a large number of electrical installations, for example in domestic or industrial low voltage electrical installations, a certain number of electrical apparatuses are assembled in a grouped manner in order to constitute what is conventionally called an electrical panel. Among these electrical devices, one can find, for example, monopolar or multipole circuit breakers, whether or not attached to differential protection blocks.

 During certain interventions carried out for example by an electrician, the electrician may need to add afterwards to the electrical panel one or more electrical current measuring devices. The electrician may wish this addition to be made temporarily or permanently. Often, there is no more space available on the electrical panel for a temporary or permanent addition of one or more electrical current measurement devices.

The electrician then manages to add electrical connections using visible electrical cables and to install on or beside the electrical panel, in any available location, one or more electrical current measurement devices. For example, if a circuit breaker on the electrical panel supplies a load with an electric current whose intensity the electrician wishes to measure, the electrician must disconnect the electrical connection between the circuit breaker and the load and use exposed cables to establish a bypass of the electric current in order to pass it through the electric current measuring device temporarily installed at a certain distance from this circuit breaker.

The electrician can also identify the electric cable that carries current between the circuit breaker and the load, move this cable without disconnecting it in order to separate it from other adjacent cables, surround this cable with a portable device used to inductively measure the current passing through the cable, then electrically connect this device with visible cables to a measured current display device installed temporarily at a certain distance from the circuit breaker.

 It is understood that such an intervention, even carried out temporarily, has a certain number of drawbacks and a certain number of dangers. First, the electrician can easily make connection errors. A connection error can result in either an electrical accident which could cause a personal accident or damage to devices. On the other hand, the current measuring device is located at a place distant from the circuit breaker which corresponds to it and, if the electrician has in this way installed a large number of current measuring devices each of which is supposed to correspond to a particular circuit breaker or a particular phase of circuit breaker, the electrician can easily be mistaken by reading a measurement displayed on a current measuring device believing that it corresponds to a particular circuit breaker or to a particular phase while it corresponds in fact to another circuit breaker or to another phase. On the other hand, the electrical connections added by the electrician using visible cables can let through very large electric currents, for example several tens or several hundred amps, which can cause either dangerous induced currents or harmful either overheating of certain parts of these visible cables, this heating can be as dangerous or harmful.

 An object of the present invention is to provide an electrical current measurement block intended to be installed on an electrical panel composed of a plurality of electrical devices each of which delivers an electrical current to a load, the intensity of which can be measured by said electric current measuring block.

 Another object of the present invention consists in proposing such an electric current measurement block avoiding the installation of a device for displaying the measured current located in a place remote from the electrical equipment of which said electric current measurement block measures the intensity of the electric current delivered.

 Another object of the present invention consists in proposing such an electric current measurement block making it possible to avoid errors in the assignment of an electric current measurement block to a particular electrical apparatus.

 Another object of the invention consists in proposing such an electric current measurement block whose design makes it possible to be able to use it as a device making it possible to display on itself the electric current which passes through it or as device allowing a remote display of the electric current which crosses the device.

 The invention therefore relates specifically to an electrical current measuring block intended to be installed on an electrical panel composed of a plurality of electrical apparatuses each of which delivers to a load, via electrical power cables, an electrical current, the intensity can be measured by said electrical current measuring block, each electrical apparatus comprising on one side face output connection pads.

 According to an essential characteristic of the invention, said electrical current measuring block comprises, on a lateral face, input connection pads and on an opposite lateral face, output connection pads, in that said connection pads inputs of the electric current measurement block are designed so as to connect directly and simultaneously to said respective output connection pads of one of said electrical apparatuses and in that said output connection pads of the electric current measurement block are designed to connect directly and simultaneously to said electric power cables of said load which is normally connected to the same electrical equipment.

According to a particular embodiment of the invention, said electric current measurement block comprises
an insulating lower case
an insulating upper case;
metal parts, each of which has one end forming a said connection block for input of the measuring block and another end forming a said connection block for output of the measuring block
magnetic coil toroids, each surrounding a central wall of one of said respective metal parts; and
a display and control assembly designed so as to be mounted on a front face of said upper casing and making it possible to control a selection of one of said magnetic coil toroids, to receive electrical signals from said magnetic coil toroid thus selected and display a value indicative of the intensity of the electric current flowing through the metal part surrounded by this same magnetic coil toroid.

According to another particular embodiment of the invention, said display and control assembly comprises:
a display device; and
a switch making it possible to be able to establish at will an electrical connection between one as desired of said magnetic coil cores and said display device.

According to another particular embodiment of the invention, said display and control assembly further comprises
a lower plate designed to be fixed in said upper housing in the vicinity of a window formed in a front face of said upper housing and supporting a terminal block
an upper plate designed to be fixed laterally to the lower plate through said window, to have a central part located at the front of said front face of the upper housing and to be able to support at its said central part both said display device and said switch
appropriate electrical connections connecting said magnetic coil toroids, said switch said display device via said terminal block; and
an auxiliary box coming to surround both said upper plate, said switch and said display device, leaving accessible from the outside a control panel of said switch and leaving visible from the outside the indications of said display device.

These objects, characteristics and advantages as well as others of the present invention will be better understood during the detailed description of an exemplary embodiment which follows, illustrated by the appended figures among which
Figure 1 is a general perspective view of an electric current measurement block according to the present invention, this block being associated with a conventional circuit breaker
Figure 2 is a general perspective view of the electric current measuring block of Figure 1;
Figure 3 is an exploded perspective view of the electric current measuring block of Figure 2;
FIG. 4 is a perspective view of the electric current measurement block of FIG. 2, this view being taken from above and the rear of the measurement block and certain parts of the outer casing of the measurement block being removed in order to show some internal details of the measuring block;
Figure 5 is a perspective view similar to that of Figure 4 but in which other parts of the outer casing of the measuring block are removed to show some other internal details of the measuring block;
Figure 6 is a perspective view of the measurement block as shown in Figure 5 but this view is taken from above and the front of the measurement block;
Figure 7 is a top view of the electric current measuring block as shown in Figures 5 and 6;
Figure 8 is a side view of the electric current measuring block of Figure 7;
Figure 9 is a front view of the electric current measuring block of Figure 7;
Figure 10 is a perspective view similar to that of Figure 1 but in which the electric current measuring block is used so as to display the electric current measured remotely instead of being used in order to perform a display on him of the measured electric current; and
Figure 11 is a perspective view similar to that of Figure 1 but in which is interposed between the electric current measurement block and the circuit breaker a conventional differential protection block.

 In FIG. 1, there is a block of electrical current measurement 1 according to the present invention and a conventional electrical apparatus 2. In general, the electrical apparatus 2 is mounted vertically on an electrical panel (although it is represented horizontally on the figures), and there is in fact provided a large number of electrical devices 2 similar or different from each other, together constituting what is called an "electrical panel". In the embodiment of Figure 1, the electrical apparatus 2 is a circuit breaker, more particularly a four-pole circuit breaker.

 The electrical equipment 2 must have as a common point that they have on one side face of the input connection pads and on the opposite side face of the outlet connection pads. One of the features of the electric current measuring block 1 according to the present invention resides in the fact that the block 1 is designed so that it can be coupled directly to an electrical apparatus 2, this coupling being effected at the level of the lateral face of the electrical apparatus 2 which includes the outlet connection pads. It follows from this that the electric current measuring block 1 according to the present invention has a side face including input connection pads and an opposite side face including output connection pads.

Consequently, when the block 1 is directly coupled to the electrical equipment 2, at the coupling zone, the output connection pads of the electrical equipment 2 are connected directly to the corresponding input connection pads of the measuring block 1. In FIG. 1, only the four output connection areas 3 of the measuring block are distinguished. The measuring block 1 also has a front face 4 on which a block of protrusion is mounted prominently. control and display 5 which mainly includes an ammeter 6 and a phase selection button 7. The function of block 5 will be described in more detail below.

 In FIG. 2, the same external details of the measuring block 1 can be distinguished substantially as those shown in FIG. 1. In FIG. 2, there is also a part of one of the input connection pads 8 of the measuring block. measure 1. Of course, there are the same number of input connection pads 8 as there are outlet connection pads 3. The input connection pads 8 are located on an upper side face 9 of the measuring block 1 and the output connection pads 3 are located on a lower lateral face 10 opposite the face 9.

 FIG. 3 shows in exploded view the different essential parts which constitute the measuring block 1 represented in FIGS. 1 and 2. The measuring block 1 essentially comprises an insulating lower case 11 and an insulating upper case 12. The upper case 12 can come to be fixed on the lower case 11 to form together a case having a generally parallelepiped shape. The lower housing 11 essentially comprises a bottom 13, a right side wall 14, a left side wall 15 and a part 10A of the lower side wall 10 (described previously in relation to FIG. 2), this part of the lower side wall 10A including the output connection pads 3 of the measuring block 1. The upper housing 12 generally comprises a front wall 16, a right side wall 17, a left side wall 18 and a part 10B of the lower side wall 10 (described above in relation to Figure 2). The front wall 16 has a window 19 of generally rectangular shape, the function of which will be explained later.

 The measuring block also comprises a certain number of metal parts 20, the number of these parts being equal to the number of poles of the measuring block. In the example shown, the measuring block 1 is four-pole and therefore four metal parts 20 are provided. Each metal part 20 is electrically conductive and has a generally elongated shape so that one end constitutes a range of inlet connection 8 (previously described in connection with FIG. 2) and the other end of which constitutes an outlet connection range 3 (previously described in relation to FIGS. 1 and 2). A conventional magnetic core with a coil 21 is arranged so as to surround the central part of the metallic part 20. There are as many magnetic core cores 21 as there are metallic parts 20.

 The measuring block 1 further comprises a lower metal plate 22 which is intended to be fixed inside the upper housing 12 below the window 19. The lower plate 22 comprises a window 23 which comprises a rigid part which is substantially flat on which is fixed on a terminal block 24.

 The measuring block 1 further comprises a metal upper plate 25 which generally comprises a front central flat part 26, a right lateral part 27 and a left lateral part 28. The lateral parts 27 and 28 are intended to be housed in the window 19 of the upper housing 12 so that the lower edges of the lateral parts 26, 27 are fixed on the lower plate 22 when the latter is already in place inside the upper housing 12. The front part 26 of the upper plate 25 comprises a circular window 29 in which an ammeter 6 (already described in relation to FIG. 2) can be housed and another window 30 through which a switch 7 (already described in relation to FIG. 2) ) can come and stay.

 The measuring block 1 further comprises an auxiliary box 31 which has a generally parallelepiped shape, which has four side walls, a front wall and no bottom wall and which is intended to fit over the upper plate 25. The front face of the secondary housing 31 includes a window 32 revealing the dial of the ammeter 6 and another window 33 allowing the passage of the control part of the switch 7.

 The measurement block I finally comprises a concealment 34 whose function will be explained later.

 The measuring block 1 can be generally mounted as follows. First of all, the lower housing 11 is placed and the various metal parts 20 are installed in this housing, on each of which is mounted a magnetic toroid with coil 21.

Each assembly consisting of a metal part 20 and a magnetic coil toroid 21 is housed in a corresponding housing of the lower housing 11 so that the input connection pad 8 is located outside the lower housing 11 at the level of the upper lateral face 9 (formed in a part of the upper housing 12) and that the outlet connection pad 3 is disposed outside the lower housing 11 at the level of part 10A of the lower lateral face 10. The same is mounted all the assemblies each consisting of a metal part 20 and a magnetic toroid with a coil 21 on the various corresponding housings formed in the lower housing 11.

 Then, the terminal block 24 is fixed to the lower plate 22 and the lower plate 22 is fixed in the upper housing 12. Then, each of the magnetic coil cores is electrically connected to corresponding input terminals of the terminal block 24 and then the upper case 12 on the lower case 11.

Then, the upper plate 25 is fixed on the lower plate 22 and it is mounted on the front face 26 of the upper plate 25, the ammeter 6 and the switch 7. Then, the terminals of the ammeter 6 are electrically connected and the terminals of the switch 7 to corresponding terminals of the terminal block 24 and the auxiliary housing 31 is fixed over the front face 16 of the upper housing 12.

 In this way, the measuring block 1 mounted as shown in FIG. 2 is obtained.

 The switch 7 is used to select a single one of the magnetic toroids with coil 21 so that the coil of this selected magnetic toroid is connected to the ammeter 6. Consequently, by turning the switch 7 to bring it successively to its various positions switching, each magnetic toroid coil is connected successively to the ammeter 6 and we can therefore select one of the poles for which we wish to measure the electric current, this measurement being displayed on the ammeter 6.

 In FIG. 4, the essential internal parts of the measuring block are distinguished in more detail 1. In this FIG. 4, there are in particular the input connection pads 8 of the four metal parts 20 which are mounted in the lower housing 11. There are also the four magnetic coil toroids 21 which surround each central part of the metal parts 20. In FIG. 4, the upper case 12 has been removed and consequently the assembly constituted by the lower plate 22, the upper plate 25, the ammeter 6 and the switch 7 appear to be suspended above the housing 11. The electrical connections between the coils of the four magnetic coil toroids 21 and the terminal block 24 (not visible in this figure) are not shown.

 FIG. 5 represents certain parts of the measuring block 1 according to a perspective view taken from the top and the rear of the measuring block. In this figure, we removed the upper plate 25, the ammeter 6, the switch 7 and the auxiliary box 31, so that we can see inside the upper box 12, through the window 19 provided in the front face 16 of the upper housing 12, the lower plate 22 and the terminal block 24 which is mounted thereon. There is also a more detailed distinction between the upper side face 9 which is produced on the upper housing 12 and through which the input connection pads 8 pass.

 Figure 6 is a view similar to that of Figure 5 but in which the portion of the measuring block 1 shown is seen in perspective from above and from the front. There is in particular a distinction between the lower lateral face 10 through which the outlet connection pads 3 pass, this lower lateral face 10 being in fact constituted by a face 10A formed on the lower housing 11 and another coplanar face lOB formed on the upper case 12.

 FIG. 7 represents in top view of the parts of the measuring block 1 which are represented in FIGS. 5 and 6. In this FIG. 7, one sees in particular both the input connection pads 8 and the connection pads output 3 which are located on either side of the measuring block.

 In FIG. 8, there is in particular a distinction between the shape of the metal part 20. The metal part 20 is in the form of an elongated part, the central part 34 of which is situated parallel to the end parts forming respectively the connection area. input 8 and the output connection area 3 and being located at a higher level than the connection areas. The magnetic toroid coil 21 surrounds this central part 34 of the metal part 20 and the coil of the magnetic toroid coil 21 is connected to corresponding terminals of the terminal block 24 by means of connection wires 35, 36 which pass through d 'An opening 37 formed in the lower plate 22.

 In FIG. 9, a distinction is made in particular between the magnetic toroids with a coil 21 which rest in corresponding curved parts 38 formed at the bottom 13 (already described in relation to FIG. 3) of the lower housing 11.

 In FIG. 10, it can be seen that it is possible to use the measuring block 1 described above by coupling it in the same way to an electrical apparatus of the circuit breaker type but by removing the ammeter 6 and the switch 7 and by replacing it with a cover 39. In this case, the measuring block 1 is intended to supply the electrical signals which are communicated via a connection cable (not shown) to an amperage display device installed remotely. It can be noted that this connection cable intended to connect the measuring block 1 and the amperage display device located at a distance can be a cable of small section intended to transmit the electrical signals produced in the coils of the magnetic cores with coil 21 included in the measuring block 1, these electrical signals being of low intensity. In FIG. 10, we can also see an additional part which is advantageously added to the measuring block 1, this part constituting the connection cover 34 which has already been mentioned in relation to FIG. 3. The connection cover 34 can be arranged similarly on the measuring block 1 when the latter is arranged so as to include the display device thereon (FIGS. 1 to 9) or when the latter is arranged to command a remote display of the measurement of the electric current. The connection cover 34 is intended to be housed on the front of the upper housing 12, in a coplanar manner with the front wall 16 of this upper housing 12, so as to close the space between this front wall 16 and a front wall 41 of the electrical equipment 2. When the connection cover 34 is not in place, a space exists between the front wall 16 of the measuring block 1 and the front wall 41 of the electrical equipment 2 and this space allows to have access to locking screws mounted on the input connection pads 8 of the measuring block 1 or on the output connection pads (not shown) of the electrical equipment 2, these screws being used to establish the connection physical and electrical output connection pads of electrical equipment 2 with the corresponding input connection pads of measuring block 1.

 When the person carrying out an installation blocks these screws in order to connect an electrical appliance 2 to a measuring block 1, for example by using a screwdriver which passes through the space situated between the front wall 16 and the front wall 41, this person can then install the connection cover 34 in order to make the locking screws or the corresponding connection pads inaccessible.

 In Figure 11, there is shown an alternative mounting of a measuring block 1 according to the present invention. In this mounting variant, the measuring block 1 is not directly coupled to an electrical apparatus 2 constituting a circuit breaker but is coupled to a differential protection block 42 which is itself coupled to the circuit breaker 2. In other words, the differential protection block 42 can be arranged between the circuit breaker 2 and the measurement block 1.

Claims (4)

 1. Electric current measuring block intended to be installed on an electrical panel composed of a plurality of electrical devices (2) each of which delivers to a load, via electric power cables, an electric current whose intensity can be measured by said electrical current measuring block (1), each electrical apparatus (2) comprising on an lateral face output connection pads,  said electrical current measuring block (1) being characterized in that it comprises on an lateral face (9) input connection pads (8) and on an opposite lateral face (10) output connection pads (3), in that said input connection pads (8) of the electric current measuring block are designed so as to connect directly and simultaneously to said respective output connection pads of one of said electrical equipment and in that said output connection pads (3) of the electric current measurement block are designed so as to connect directly and simultaneously to said electric cables for the power of said load which is normally connected to this same electrical apparatus (2).  2. Electric current measuring block according to claim 1, characterized in that it comprises  an insulating lower case (11)  an insulating upper case (12);  metal parts (20) for current flow, each of which has one end forming a said input connection range (8) of the measuring block and another end forming a said output connection range (3) of the measurement block measured  magnetic coil cores (21), each surrounding a central wall (35) of one of said respective metal parts (20); and  a display and control assembly designed so as to be mounted on a front face (16) of said upper housing (12) and making it possible to control a selection of one of said magnetic coil cores (21), to receive signals electric from said magnetic coil torus thus selected and display a value indicative of the intensity of the electric current flowing through the metal part (20) surrounded by the same magnetic coil torus.  3. Electric current measuring block according to claim 2, characterized in that said display and control assembly comprises:  a display device (6); and  a switch (7) making it possible to be able to establish at will an electrical connection between one of the choice of said magnetic coil cores and said display device.  4. Electric current measuring block according to claim 2, characterized in that said display and control assembly further comprises  a lower plate (22) designed to be fixed in said upper housing in the vicinity of a window (19) formed in a front face (16) of said upper housing (12) and supporting a terminal block (24)  an upper plate (25) designed to be fixed laterally to the lower plate (22) through said window (19), to have a central part (26) located at the front of said front face (16) of the upper housing and to be able to support at its said central part both said display device (6) and said switch (7)  appropriate electrical connections (36, 37) connecting said magnetic coil toroids, said switch and said display device via said terminal block; and  an auxiliary box (31) surrounding both said upper plate, said switch and said display device, leaving accessible from the outside a control panel of said switch and leaving visible from the outside the indications of said device 'display.