EP2045827B1 - Circuit breaker interruptor tube with double compression volume - Google Patents

Description

TECHNICAL AREA

The invention relates to the field of breaking chambers of power circuit breakers, and more particularly that of double volume compression breaking chambers. The invention is particularly suitable for high-voltage use, for example for voltages greater than or equal to about 72.5 kV.

STATE OF THE PRIOR ART

In the field of circuit breakers, and particularly that of power circuit breakers, it is important to use the least possible operating energy to cut off currents, whether fault currents, for example short-circuit currents, or load currents such as vacuum line currents. The documents US 4,559,425 and US 3,975,602 disclose self-blowing circuit breakers that compress a dielectric gas to blow an arc that is formed between arcing contacts during a power failure operation, or opening operation of the circuit breaker. Compression is generally performed by an operating member actuating a moving part, such as a piston, in the breaking chamber. These circuit breakers also use the energy provided by the arc under heat, thereby reducing external power consumption compared to conventional gas compression circuit breakers. In such a circuit breaker, the stroke of the moving part of the breaking chamber producing the compression is approximately proportional to the nominal voltage of the circuit breaker. The higher the nominal voltage, especially when this voltage is greater than about 245 kV, the greater the stroke, which increases the energy required for the circuit breaker to cut the current.

However, in order to cut off strong currents, that is to say currents whose value is greater than about 30% of the value of the breaking capacity assigned to the circuit breaker, it is not necessary to carry out the compression of the gas during the whole opening operation of the circuit breaker because the energy provided by the arc is sufficient to blow the arc and interrupt, without the compression stroke is completed. The documents EP 0 897 185 and EP 0 591 039 describe self-blowing circuit breakers with reduced compression stroke. These circuit breakers perform the compression of the gas only during a part of the race. But when the current is low, for example less than or equal to about 30% of the value of the breaking capacity, the energy provided by the arc is much less important than when the current is high, and if moreover the duration of the arc is long (between about 13 and 20 ms), there is a risk that the blowing is insufficient to ensure the interruption of the current.

The document " EP 0 821 382 A "discloses a current-breaking chamber according to the preamble of claim 1.

The document FR 2,892,851 discloses a current breaking chamber of a circuit breaker having two compression chambers cooperating during an opening operation of the circuit breaker. The second compression chamber injects dielectric fluid into the first compression chamber during a portion of the circuit breaker opening operation, when the pressure in the first compression chamber is less than the pressure in the second compression chamber.

In this current-breaking chamber, the cooperation between the two compression chambers makes it possible, during a strong power failure, to preserve the advantages of a reduced compression stroke produced by the first compression chamber, and when a cut of a weak current, to achieve this cut without unnecessarily increasing the external power consumption whatever the duration of the arc, and in particular when the duration of arc is long.

There are also currents, called capacitive currents, that can occur when the line of the network connected to the circuit breaker is open at one end, or that power exchange adjustment capacitors are connected to the network. The breaking of these currents, whose value is for example less than 500 A, is an operation that most circuit breakers must perform. This breaking of capacitive currents is successful if the voltage held between the contacts of the circuit breaker is greater than the restored voltage imposed by the network.

However, a dielectric breakdown can occur at the circuit breaker, in particular between the circuit breaker arcing contacts, during the breaking of the capacitive currents if the dielectric strength between contacts is lower than the voltage restored after cutoff imposed by the network. If this breakdown occurs between the instant corresponding to the cutoff and a quarter of the period of the mains voltage imposed on the circuit breaker after the cut-off time, this breakdown causes the circuit-breaker to re-ignite. Such a reignition does not produce an overvoltage on the network but can lead to damage to the insulators, for example that used for the circuit breaker nozzle.

If the breakdown occurs more than a quarter of the period of the mains voltage imposed on the circuit breaker after the cut-off time, this breakdown causes a reboot of the circuit breaker producing an excessive overvoltage on the network, which can lead to significant damage on devices connected to the network. These reboots are therefore prohibited during tests of the type required by international standards.

STATEMENT OF THE INVENTION

The object of the present invention is to provide a breaking chamber, used in particular in a power circuit breaker, for cutting off both strong and low currents, while avoiding unnecessarily increasing the external energy consumption by the circuit breaker, be there duration of the arc, and also to cut optimally capacitive currents.

For this, the invention proposes a current cutoff chamber, intended to be used in a circuit breaker, filled with a dielectric fluid. This chamber comprises a movable assembly, moving axially between a start position and an end of operation opening position of the circuit breaker.

The moving assembly comprises at least a first compression chamber whose volume decreases between the opening operation opening position of the circuit breaker and a compression end position of the first compression chamber.

The movable assembly also comprises a hollow actuating tube comprising at one end at least a first arcing contact, intended to cooperate with a second arcing contact, and openings communicating the inside of the operating tube with the outside the current-breaking chamber, the inside of the operating tube communicating with the first compression chamber between a separation position of the two arcing contacts and the end-of-operation position of opening of the circuit breaker.

The movable assembly further comprises a second compression chamber, communicating at a first end with the first compression chamber, the volume of which decreases between the position of separation of the contacts and the end position of the opening operation of the circuit breaker, for injecting dielectric fluid into the first compression chamber between the separation position of the two arcing contacts and the end-of-operation position of opening of the circuit breaker, when the pressure in the first compression chamber is lower than the pressure in the second compression chamber.

The moving assembly also comprises means obstructing the openings of the operating tube from the opening operation opening position of the circuit breaker to an intermediate position reached between the position of separation of the two arcing contacts and the position of end of opening operation of the circuit breaker.

In this power failure chamber, the compression end position of the first compression chamber is reached before the end of the circuit breaker opening operation position, and a compression end position of the second compression chamber is reached after the compression end position of the first compression chamber.

The cooperation between the two compression chambers makes it possible, during a strong power failure, to retain the advantages of a reduced compression stroke produced by the first compression chamber, and during a cutoff of a low current, to achieve this break without unnecessarily increasing the external power consumption of the circuit breaker, regardless of the duration of the arc and in particular when the arc duration is long.

Indeed, when the current is low and the duration of the arc is important, the second compression chamber allows to maintain the blowing of the arc, initially produced by the first compression chamber, during the entire arc duration, and this by avoiding excessive external energy consumption thanks to the use of the energy supplied by the arc for the duration of the blowing.

The power cutoff chamber may include a first compression volume that becomes a thermal expansion volume for arc blowing when the compression in that volume is complete, and further comprises a second compression volume. The first compression chamber can be quickly put under overpressure using the displacement of the arcing contacts during only a first part of the total stroke of the moving assembly. The compression in the first chamber is therefore performed during a reduced compression stroke, allowing a rapid increase in pressure, and involving blowing performance higher than those devices whose compression is performed during the entire displacement stroke. The second compression chamber then intervenes as needed to contribute to the end-of-stroke blow-out of the arcing contacts.

The fact that the compression is first performed in the first chamber, then in the second chamber, which has a smaller piston section than the first and whose maximum pressure is reached at the end of travel of the contacts, reduces the energy used to maneuver the breaking chamber.

Thus, for example, the use of the breaking chamber according to the invention in a circuit breaker makes it possible to use operating members comprising a spring mechanism requiring little energy.

In addition, the means obstructing the openings of the operating tube from the opening operation opening position of the circuit breaker to an intermediate position reached between a position of separation of the two arcing contacts and the end position of opening operation of the circuit breaker, or between the position of separation of the two arcing contacts and an opening position of the first compression chamber obtained during the separation of one of the arcing contacts with a nozzle (this contact arc and the nozzle cooperating to close the first compression chamber at one of its ends), allow the volume of the operating tube to be overpressured at the same time as the first compression chamber before the separation of the contacts arc and practically keep this overpressure for a few milliseconds after the separation of the contacts, and thus maintain a high density of gas between the arcing contacts during the critical period of time. This can cause a dielectric breakdown between the arcing contacts, regardless of the duration of the arc. This increase in the density of gas thus prevents the occurrence of such a dielectric breakdown. This obstruction of the openings formed in the maneuvering tube makes it possible to avoid blowing through these openings during this critical period.

This applies in particular when the breaking of the capacitive currents is particularly critical, that is to say when it is performed with a minimum arc duration, for example an arc duration equal to or less than approximately 1 ms because in this case, the arcing contacts are closest to each other when the restored voltage reaches its maximum value (for example 10 ms after the cut-off time for a 50 Hz network), increasing the risk a dielectric breakdown. The high density of dielectric gas in the first chamber and in the maneuvering tube limits this risk.

When the openings are no longer obstructed, they make the interior of the operating tube communicate with the outside of the current cut-off chamber, the full blowing is then restored for the breaking of the strong currents.

The dimensions and the positioning of the obstruction means of the openings relative to the maneuvering tube may be such that the intermediate position is reached after a duration of between about 2 ms and 7 ms, after the position of separation of the two arc contacts. . After this time, the arcing contacts can be quite far apart, thus eliminating the risk of dielectric breakdown occurring between the arcing contacts.

The means for obstructing the openings of the maneuvering tube may comprise at least one deflector disposed inside the operating tube.

The baffle may be movable relative to the maneuvering tube.

The first compression chamber may be formed by at least a first tubular element.

The second compression chamber may be formed by at least two second coaxial tubular members. One of the two second tubular elements may at least partly form the operating tube.

In this case, the second compression chamber may be closed at a second end by at least one sleeve disposed between the two second coaxial tubular elements. The means for obstructing the openings of the maneuvering tube may comprise the sleeve.

The maneuvering tube may be movable relative to the sleeve.

The first compression chamber may comprise at one end a nozzle intended to cooperate with the second arcing contact to effect an opening of the first compression chamber between said intermediate position and the end position of the opening operation of the circuit breaker.

The second compression chamber can communicate with the first compression chamber via at least one valve.

The first and second arcing contacts may be axially movable relative to each other.

The invention also relates to a circuit breaker comprising a current-breaking chamber as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

• les figures 1 à 5 représentent une chambre de coupure de courant, objet de la présente invention, selon un mode de réalisation particulier, au cours de différentes étapes d'une opération d'ouverture de disjoncteur,
• la figure 6 représente un disjoncteur, également objet de la présente invention, comportant une chambre de coupure de courant selon l'invention.

The present invention will be better understood on reading the description of exemplary embodiments given purely by way of indication and in no way limiting, with reference to the appended drawings in which:

• the Figures 1 to 5 represent a current-breaking chamber, object of the present invention, according to a particular embodiment, during different stages of a circuit breaker opening operation,
• the figure 6 represents a circuit breaker, also object of the present invention, comprising a current breaking chamber according to the invention.

Identical, similar or equivalent parts of the different figures described below bear the same numerical references so as to facilitate the passage from one figure to another.

The different parts shown in the figures are not necessarily in a uniform scale, to make the figures more readable.

The different possibilities (variants and embodiments) must be understood as not being exclusive of each other and can be combined with one another.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

The figure 1 represents a current-breaking chamber 100 according to a particular embodiment. In this figure, the breaking chamber 100 is in the engaged position, that is to say in the position in which is the interrupting chamber 100 at the beginning of a power failure operation, that is to say at the beginning of an operation of opening of the circuit breaker including the breaking chamber 100.

The breaking chamber 100 comprises a casing 102 filled with a dielectric fluid, here a dielectric gas, under pressure. This gas may for example be sulfur hexafluoride ( SF ₆ ), nitrogen ( N ₂ ), dry air, carbon dioxide ( CO ₂ ) or a gaseous mixture.

The cutting chamber 100 comprises a first tubular element 104 forming a first compression chamber 106. This first compression chamber 106 is closed in particular at a first end by an operating tube 108. The first tubular element 104 forms, at the level of a second end of the first compression chamber 106, a nozzle 110. The interrupting chamber 100 also comprises a first and a second arcing contact, respectively 112 and 114, movable relative to each other along an axis AA. On this figure 1 the second arc contact 114 cooperates with the nozzle 110 to close the first compression chamber 106 at its second end. In the particular embodiment described herein, the first arcing contact 112 is movable and the second arcing contact 114 is fixed. The first arcing contact 112, here integrated at one end of the operating tube 108, is disposed inside the first compression chamber 106.

The breaking chamber 100 comprises at least two second tubular elements 116 and 118, coaxial with respect to the axis AA. One of the two second tubular elements 116 forms part of the operating tube 108. The space between the two second tubular elements 116 and 118 forms a second compression chamber 120. Typically, the volume of the second compression chamber 120 is less than that of the first compression chamber 106. On the figure 1 , the second compression chamber 120 communicates with the first compression chamber 106, at a first end, with at least one valve 122, for example a one-way valve, integrated with the operating tube 108. This valve 122 opens only when the pressure in the second compression chamber 120 is greater than that in the first compression chamber 106. The second compression chamber 120 is closed at a second end by a sleeve 124 having a filling valve 126 used after the operation. opening circuit breaker, so that gas can enter the second compression chamber 120 when the interrupting chamber 100 returns to the engaged position.

The interrupting chamber 100 also has permanent contacts 128, 130 causing the current to flow through the circuit breaker when the interrupting chamber 100 is in the engaged position. Like the arcing contacts 112, 114, the permanent contacts 128, 130 are axially movable relative to each other along the axis AA. In the mode of embodiment described here, only the contact 130, integrated with the first tubular element 104, is movable.

The first tubular element 104 is connected to a rod 132 from which operating means of the circuit breaker, not shown on the figure 1 , can realize the opening of the circuit breaker. This rod 132 is integral with a deflector 134 disposed inside the operating tube 108, and here inside the second tubular element 116, and closes the inside of the operating tube 108 at one end, other end being closed by the arcing contacts 112 and 114. The deflector 134 is also movable relative to the operating tube 108 along the axis AA.

Openings 136 are made through the second tubular element 116 and make it possible to communicate the inside of the operating tube 108 with the rest of the envelope 102. figure 1 these openings 136 are obstructed by the deflector 134 and the sleeve 124.

The first tubular element 104, the operating tube 108, the second tubular elements 116, 118, the rod 132 and the deflector 134 form a mobile assembly 138 adapted to be displaced along the axis AA in the casing 2 during the operation circuit breaker opening, or the power failure operation.

The figure 2 represents the interrupting chamber 100 in the compression end position of the first compression chamber 106. In this position, with respect to the engaged position represented on the figure 1 , the first tubular element 104, the rod 132 and the deflector 134 have been moved along the axis AA by operating means, not shown, connected to the rod 132.

The displacement of the first tubular element 104 here reduces the volume of the first compression chamber 106 because the operating tube 108 and the second tubular elements 116, 118 remain stationary, thus increasing the pressure inside the first compression chamber 106 To immobilize the operating tube, it is possible to use metal balls, as on the Figure 2A of the document FR 2892851 ; but other means are possible.

In general, the axial displacement stroke achieved during this portion of the circuit breaker opening operation is about one third to one half of the total axial displacement stroke of a circuit breaker opening operation.

On the figure 2 the permanent contacts 128 and 130 are no longer in contact with each other, unlike the arcing contacts 112, 114 which are still in contact with each other. Therefore, in the compression end position of the first compression chamber 106, the current passes only through the arcing contacts 112, 114. The arcing contacts 112, 114 therefore remain in contact during the entire compression phase. of the first chamber 106.

In addition, during this part of the opening operation of the circuit breaker, the deflector 134 has been moved axially inside the operating tube 108, here over a distance equivalent to that traveled by the first tubular element 104. On the figure 2 the deflector 134 no longer closes the openings 136. However, these openings 136 are still obstructed by the sleeve 124.

The figure 3 represents the breaking chamber 100 after the separation of the arc contacts 112, 114. With respect to the compression end position of the first compression chamber 106, the moving assembly 138 has moved along the axis AA relative to the fixed elements of the circuit breaker, here the second arcing contact 114, the permanent contact 128 and the sleeve 124. On this figure 3 the arcing contacts 112 and 114 are no longer in contact with each other. The operating tube 108 and the second tubular elements 116, 118 are driven in movement along the axis AA by the first tubular element 104.

In the case of a cut of a current the separation of the arcing contacts 112, 114 causes the formation of an arc between these two arcing contacts 112, 114, as well as the setting in communication of the volume of the first compression chamber 106 with that of the inside of the operating tube 108. In this position, the openings 136 are no longer obstructed by the deflector 134 but only by the sleeve 124. The volume formed by that of the first compression chamber 106 and that of the inside of the maneuvering tube is thus closed at a first end by the deflector 134 and the sleeve 124, and at a second end by the second arc contact 114 cooperating with the nozzle 110. With respect to the position represented on the figure 2 , the volume of the second chamber of compression 120 has also been reduced by the displacement of the tubular elements 116, 118 relative to the sleeve 124, thus increasing the pressure inside the second chamber 120. Since the compression in the first compression chamber 106 is complete and that the compression of the gas takes place only in the second chamber, the energy used for the displacement of the moving assembly 138 is less than that used for the compression of the first chamber 106.

In the case of a capacitive power failure, whose value is for example less than about 100 A, since the openings 136 are still obstructed by the sleeve 124, a high density of dielectric gas is present in the first chamber of compression 106 and inside the operating tube 108. This large density of gas prevents the occurrence of a dielectric breakdown between the arc contacts 112, 114. The obstruction of the openings 136 made here avoids a unnecessary blowing through the interior of the operating tube 108 and through the openings 136, during a period where the distance between contacts is insufficient to have a break of strong currents.

The figure 4 represents the breaking chamber 100 in a position where the openings 136 are no longer obstructed. Thus, the volume formed by that of the first compression chamber 106 and that of the inside of the operating tube 108 is therefore always closed at its second end by the nozzle 110 and the second arc contact 114, but is open at level of its first end through the openings 136 which are no longer obstructed.

Thus, an intermediate position from which the openings 136 are no longer obstructed corresponds to a position reached between that represented on the figure 3 and the one represented on the figure 4 , or between a position of separation of the arcing contacts and a position of opening end of the circuit breaker, or between a position of separation of the arcing contacts and an opening position of the first compression chamber 106 by the separation of the nozzle 110 and the second arc contact 114.

The duration corresponding to the passage of the separation position of the two arcing contacts 112, 114 to the intermediate position can be adjusted thanks to the dimensions of the openings 136, the deflector 134 and the sleeve 124, and the positioning of these elements. one against another. This duration may in particular be adjusted so that it is between about a quarter of a period and half a period of a mains voltage applied to the circuit breaker after the position of separation of the two arcing contacts 112, 114. For example , this duration is between about 5 ms and 10 ms in the case of a mains voltage whose frequency is equal to 50 Hz, and is between about 4.2 ms and 8.3 ms in the case of a mains voltage whose frequency is equal to 60 Hz. Preferably, this duration is adjusted so that it is between about 2 ms and 7 ms after the position of separation of the two arcing contacts 112, 114. Indeed after this period, the openings 136 are no longer obstructed because the distance between the arcing contacts 112, 114 is such that there is no longer any risk of dielectric breakdown between the arcing contacts 112, 114 during a capacitive power failure. This applies in particular when the breaking of the capacitive currents is particularly critical, that is to say when it is performed with the minimum arc duration, for example an arc duration equal to or less than approximately 1 ms because in this case In this case, the arc contacts are closest to one another after the arc has been cut off, for a given duration after a break.

The figure 5 represents the interrupting chamber 100 in the end position of the circuit breaker opening operation, corresponding to a compression end position of the second compression chamber 120.

In the case of a fault current short-circuit arc blowing occurs when the arc contact 114 no longer cooperates with the nozzle 110 to close the first compression chamber 106. Indeed, when the first compression chamber 106 opens at the nozzle 110, the overpressure created in the first compression chamber 106 causes a blowing of the volume of gas contained in the first chamber 106 to the casing 102 through the nozzle 110.

If the duration of the arc is short, the blowing carried out by the first compression chamber 106 is sufficient to extinguish the arc.

If the duration of the arc is long, and the current value is close to the fault value, the energy provided by the arc is sufficient for the blowing created by the first compression chamber 106 extinguishes the arc.

On the other hand, if the duration of the arc is long, and the value of the current is weak, that is to say less than approximately 30% of the default value, the energy brought by the arc is insufficient. for the blowing created by the first compression chamber 106 extinguishes the arc. The arc is therefore always present after the decompression of the gas present in the first chamber 106. The pressure in the first compression chamber 106 is then lower than that in the second compression chamber 120, which causes the opening of the valve 122. Gas is then blown from the second compression chamber 120, and this continuous blowing until the moving assembly 138 reaches the end of travel or the arc goes out.

On this figure 5 it can be seen that there remains a dead volume in which the compressed gas can be kept and contributed to the blowing when the pressure in the volume 106 has dropped.

The present invention also relates to a circuit breaker 200, shown in FIG. figure 6 , comprising a breaking chamber 100 as described above. This circuit breaker 200 is, for example, a high or medium voltage power circuit breaker, that is to say used for voltages greater than about 52 kV. The interrupting chamber 100 is connected to an actuator 202 for actuating the compression in the interrupting chamber 100 and the opening of the circuit breaker 200.

Although several embodiments of the present invention have been described in detail, it will be understood that various changes and modifications can be made without departing from the scope of the invention defined in the claims.

It is also possible to produce means displacing the second arcing contact in a direction opposite to the movement of the moving assembly during the opening operation of the circuit breaker. The principle described is therefore applicable in the same way in the case where the two arc contacts are movable).

Claims (13)

1. A current interrupting chamber (100), for use in a circuit-breaker (200) and filled with a dielectric fluid, including:

   a moving assembly (138) which is axially displaceable between a start position and an end position of an operation of opening the circuit-breaker (200), characterized in that it comprises at least:

   a) a first compression chamber (106), the volume of which diminishes between the start position of an operation of opening the circuit-breaker (200) and a position corresponding to the completion of the compression process in the first compression chamber (106);

   b) a hollow drive tube (108) having at one end at least one first arcing contact (112) adapted to cooperate with a second arcing contact (114), and further having ports (136) for bringing the interior of the drive tube (108) into communication with the outside of the current interrupting chamber (100), the interior of the drive tube (108) being in communication with the first compression chamber (106) between a position corresponding to the separation of the two arcing contacts (112, 114) and the end position of an operation of opening the circuit-breaker (200);

   c) a second compression chamber (120), which is in communication at a first end thereof with the first compression chamber (106), and the volume of which diminishes between the start position and the end position of an operation of opening the circuit-breaker (200), adapted to inject dielectric fluid into the first compression chamber (106) between the position corresponding to the separation of the two arcing contacts (112, 114) and the end position of an operation of opening the circuit-breaker (200), when the pressure in the first compression chamber (106) is lower than the pressure in the second compression chamber (120); and

   d) means (124, 134) for obstructing the ports (136) in the drive tube (108) as from the start position of an operation of opening the circuit-breaker (200) and up to an intermediate position which is attained between the position corresponding to the separation of the two arcing contacts (112, 114) and the end position of an operation of opening the circuit-breaker (200);

   the position corresponding to the completion of the compression process in the first compression chamber (106) being attained before the end position of an operation of opening the circuit-breaker (200), and a position corresponding to the completion of the compression process in the second compression chamber (120) being attained after the position corresponding to the completion of the compression process in the first compression chamber (106).
2. A current interrupting chamber (100) according to claim 1, wherein the dimensions and positioning of the means (124, 134) for obstructing the ports (136) relative to the drive tube (108) are such that the intermediate position is attained after a period of time lying in the range about 2 ms to 7 ms after the position corresponding to the separation of the two arcing contacts (112, 114).
3. A current interrupting chamber (100) according to any preceding claim, wherein the means for obstructing the ports (136) of the drive tube (108) include at least one deflector (134) which is disposed inside the drive tube (108).
4. A current interrupting chamber (100) according to claim 3, wherein the deflector (134) is movable relative to the drive tube (108).
5. A current interrupting chamber (100) according to any preceding claim, wherein the first compression chamber (106) comprises at least one first tubular element (104).
6. A current interrupting chamber (100) according to any preceding claim, wherein the second compression chamber (120) comprises at least two coaxial second tubular elements (116, 118), one of the two second tubular elements (116) partly constituting the drive tube (108).
7. A current interrupting chamber (100) according to claim 6, wherein the second compression chamber (120) is closed at a second end thereof by at least one sleeve (124) which is disposed between the two coaxial second tubular elements (116, 118).
8. A current interrupting chamber (100) according to claim 7, wherein the means for obstructing the ports (136) in the drive tube (108) comprise the sleeve (124).
9. A current interrupting chamber (100) according to claim 7 or claim 8, wherein the drive tube (108) is movable relative to the sleeve (124).
10. A current interrupting chamber (100) according to any preceding claim, wherein the first compression chamber (106) includes at one end thereof a nozzle (110) which is adapted to cooperate with the second arcing contact (114), whereby to define an opening of the first compression chamber (106) between said intermediate position and the end position of an operation of opening the circuit-breaker (200).
11. A current interrupting chamber (100) according to any preceding claim, wherein the second compression chamber (120) is in communication with the first compression chamber (106) through at least one valve (122).
12. A current interrupting chamber (100) according to any preceding claim, wherein the first and second arcing contacts (112, 114) are movable axially relative to each other.
13. A circuit-breaker (200) including a current interrupting chamber (100) according to any preceding claim.

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