FR2727240A1 - BREAKING CHAMBER OF AN ELECTRIC CIRCUIT BREAKER - Google Patents

Abstract

The present invention relates to an interrupting chamber of an electric circuit breaker. The interrupting chamber (9) of the circuit breaker comprises an arcing chamber (10) containing a fixed contact (8) and a movable contact (7), which at the time of their separation form an arc between them. The arc forming chamber (10) communicates with the inlet of a so-called arc extinguishing chamber (11). This interrupting chamber (9) is characterized in that it further comprises cooling elements (16) placed inside the arcing chamber (10) so as to cool the gases surrounding the movable contact. (7). These coolers (16) are placed around the movable contact (7) or at a certain distance therefrom and may consist, among others, of plates (17) or tubes (18).

Description

BREAKING CHAMBER OF AN ELECTRIC CIRCUIT BREAKER

  The invention relates to the breaking chamber of an electric circuit breaker, comprising an arc forming chamber containing a fixed contact and a movable contact, which, at the moment of their separation forming an arc between them, said training chamber

  communicating with the entrance of a second chamber, said arc extinction.

  In known circuit breakers, especially miniature circuit-breakers, it has been observed that, after the switching of the arc, and the displacement thereof in the breaking chamber 10 towards the extinguishing chamber, a current of a few ampere subsists on the moving contact. This weak current residue is the origin of a Greeklabeling phenomenon which is defined by the disappearance in a few milm of the arc paent

  in the extinction chamber and appearance of it at the mobile contact.

  The present invention solves this problem and proposes a circuit breaker burner chamber.

  in which the risks of reclasking are considerably reduced.

  To this end, the subject of the present invention is a switching chamber of an electric dijoctor comprising an arc forming chamber enclosing a fixed contact and a movable contact, which, at the moment of their separation, form an arc between them. The formation chamber communicates with the inlet of a second so-called arc-quenching chamber, and the interrupting chamber is characterized in that it comprises, in the form of a magnet, a cooler placed inside the chamber arc formation so as to cool

  the gases present around the moving contact after switching the arc.

  In a particular embodiment, the aforementioned refiders are placed around the moving contact. According to an alternative embodiment, the aforementioned coolers are placed between the movable contact and the aforementioned extinction chamber, at a required distance ermi of said moving contact. According to one particular embodiment, the aforementioned chillers are constituted by

plates or tubes.

  According to a first embodiment, the aforementioned efodisseu includes two sets

  plates parallel to each other, arranged on either side of the movable contact.

  Advantageously, these plates extend substantially parallel to the moving contact.

2 2727240

  According to an alternative embodiment, the aforementioned coolers comprise two sets

  tubes parallel to each other, arranged on either side of the movable contact.

  Advantageously, these tMbes extend substantially perpendicular to the moving contact.

  Advantageously, the aforementioned coolers are made of metal or ceramic.

  But other advantages and features of the invention will better appaMatrate in the

  detailed description which follows and refers to the attached drawings given solely for the purpose of

  for example, and in which: FIGS. 1, 2 and 3 are three diagrammatic sectional views, illustratively illustrating three

  particular embodiments of the invention.

  Figs. 1a, 2a and 3a are side schatic views, illustrating the shape and

  the arrangement of the coolers corresponding to FIGS. 1, 2 and 3, respectively.

  In the figures, there is seen a miniature circuit breaker pole 1 having an insulating housing B, having on its front face an operating lever 2 and on its two side faces 3, 4, connection terminals 5, 6. Inside the housing B are housed, as is known per se, a movable contact 7 and a fixed contact 8. The movable contact 7 is controlled by a control mechanism (not shown) connecting the aforementioned lever 2 to the movable contact 7 for the contact closure. In this housing B are also housed a thermal release and an electromagnetic release (not shown), may cause, in case of overload or short circuit, an automatic opening of the contacts. The lower part of the housing B reaffirms an interrupting chamber 9 constituted by a first arc-forming chamber 10, communicating with the inlet of a second chamber 11, called an arc quenching chamber, comprising separations 13 made of by a stack of plates (or sheets) which extend plralllm t to the base 12 of the botter B. The movable contact 7 extends substantially perpendicular to the plane of the plates 13, so as to draw an arc between the contacts 7, 8 at the time of their separation, the initial direction of which is sensibly parallel to the plates 13. The aforementioned breaking chamber 9 is delimited laterally by arc-shaped horns 14, 15 respectively connected to the two aforementioned terminals 5, 6. arc 14, 15 are arranged to capture the arc

  pulled between the contacts 7, 8 during their separation.

3 2727240

  As such a circuit breaker is well known to specialists, it will be unnecessary to describe in more detail

  its arrangement or operation.

  According to the embodiment illustrated in Figures 1 and la, refioidisment lémnents 16 are placed around the movable contact 7 and are intended to cool the hot gases present around the movable contact 7 after switching the arc. These refidisses 16 are constituted by two sets 17a, 17b of plates 17 parallel to each other, said

  sets being disposed respectively on either side of the movable contact 7.

  According to the embodiment illustrated in FIGS. 2 and 2a, these cooling elements 16, or coolers, consist of two sets 18a, 18b of tubes 18 parallel to one another,

  said assemblies 18a, 18b being disposed on either side of the movable contact 7.

  According to the embodiment illustrated in FIGS. 3 and 3a, these tubes 18, instead of being arranged around the moving contact 7, are placed in the arc-forming chamber 10, at a certain distance from said contact 7, by example at the same distance separators 13 and the movable contact 7. Note that in this case, the two sets of tubes 18a, 18b sernt

  separated by a distance a greater than the width of the movable contact 7.

  In these three embodiments, the large exchange surface of the coolers 16 causes a

cool ignificative gas.

  Thus, after switching the arc, hot organic vapors due to evaporation of the insulating walls (19) located between the forming and extinguishing chambers, are formed in the breaking chamber 9, (mainly during the stagnation of the bow). These organic vapors favor the appearance of the phenomenon of reclamation, in particular when they are combined with an increase in the arc voltage observed during the

  penetration of the arc into the chamber.

  The cooling of the vapors situated in the vicinity of the moving contact 7 by the above-mentioned cooling elements 16 makes it possible to considerably reduce the risk of appaition of

this phenomenon of reclamation.

  Naturally, the invention is not limited to the described and illustrated embodiments which have been given by way of example only. It is thus possible to consider other

  forms and arrangements of coolers without departing from the scope of the invention.

  On the contrary, the invention includes all the technical equivalents of the means thus described.

  that their combinations if they are carried out according to his spirit.

4 2727240

REVEDICATIONS

  1. A circuit breaker of an electric circuit breaker comprising an arc forming chamber containing a fixed contact and a movable contact, which, at the time of separation, form an arc between them, said operating chamber being operated with the input of a second so-called arc extinction chamber, characterized in thatdele further comprises at least one cooler (16) placed inside the arc forming chamber (10) so as to cool the gases present around the moving contact (7)

after switching the arc.

  2. Cut-off chamber according to claim 1, characterized in that the cooling devices

  mentioned above (16) are placed around the moving contact (7).

  3. Cutoff chamber according to claim 1, characterized in that the aforesaid refrmidim (16) are placed between the movable contact (7) and the extinction chamber preci (11),

  at a predetermined distance from said movable contact (7).

  4. Cutoff chamber according to any one of the preceding claims, 'ise

  in that the aforesaid coolers (16) consist of plates (17).

  5. Cutoff chamber according to any one of claims 1 to 3, characterized in that

  that the aforesaid coolers (16) consist of tubes (18).

  6. Cutoff chamber according to claim 4, characterized in that the aforementioned (16) comprise two sets of plates (17a, 17b) parallel to each other,

  disposed on either side of the movable contact (7).

  7. Cutoff chamber according to claim 5, characterized in that MEfroidissems supra comprise two sets of tubes (18a, 18b) parallel to each other, disposed of

  both sides of the moving contact (7).

  8. Cutoff chamber according to claim 6, characterized in that the aforementioned plates

  (17) extend parallel to the movable contact (7).

  9. Cutoff chamber according to claim 7, characterized in that the aforementioned tubes

  (18) extend substantially perpendicularly to the movable contact (7).

2727240

  10. Cutting chamber according to any one of the preceding claims, characterized in that the aforesaid coolers (16) are made of metal or ceramic.