Patent Description:
Generally, multi-pole residual current operated circuit breakers with overcurrent protection as described in Chinese patent (<CIT>) "A Combined Circuit Breaker with Auxiliary Trip Unit and Multi-pole Circuit Breaker Unit Combined" and the Chinese Patent (<CIT>) "Multi-Pole Differential Circuit Breaker" are of a spliced structure respectively, and this kind of products are formed by combining circuit breakers of different number of poles and splicing an adaptive residual current trip device to one side of a circuit breaker combined module to constitute the multi-pole residual current operated circuit breaker with overcurrent protection. Document <CIT> discloses for example a multipolar differential switch. These products are large in volume, especially in a width direction, and occupy a relatively large installation space, thereby resulting in reduction of the number of installation loops of a terminal control cabinet under the same volume condition. In order to satisfy the requirements to the number of installation loops, only the number of the terminal control cabinets is increased or the size of each terminal control cabinet is increased, which causes more product consumables, increase of the use cost and relatively low installation convenience for the user.

In recent years, some foreign companies launched small-size integrated multi-pole current operated circuit breakers having overcurrent protection. These products are integrally made of a circuit breaker unit and a residual current trip device still placed at one side of the circuit breaker unit respectively. The compression in size of the product in a width direction is realized mainly by virtue of a small-sized design of each of the structure modules constituting the two devices. Because such design still follows a principle of a spliced structure, the residual current trip device is arranged at one side of the circuit breaker module. By means of such layout structure and connection manner, an electrical loop of a circuit breaker unit of a pole farther apart from the residual current trip device be relatively long, and in addition, due to more electrical connections and a complicated wiring structure, large power consumption in operation and use is caused to the products, and more valuable space is occupied, thus leading that the current specification of the product cannot be expanded (not beyond 25A at most). On the other hand, wires of the circuit breaker unit of each pole to penetrate through a zero sequence current mutual inductor of the residual current trip device are complicated in wiring process and relatively difficult in connection, and therefore, the production cost is increased and there is still the problem that more process space is reserved. Furthermore, each circuit breaker unit must be equipped with an independent operating mechanism, or may not work normally, and each operating mechanism must occupy a relatively large valuable space.

Upon massive analysis of the prior art, the applicant finds that the existing multi-pole residual current operated circuit breaker product having overcurrent protection basically follows a principle of the spliced structure no matter of a spliced structure or an integrated structure, and it is very difficult to further increase a current specification or reduce the volume. Because the small-sized and high-current development trends of the low-voltage circuit breaker are inherently of a pair of mutually constrained contradictions, for example, if the current specification of the existing product is increased from 25A to 40A, it is at least necessary to increase a wire section and a heat insulation pitch inside the product. However, the crowding degree of the internal space of the existing product approaches an extreme limit, and therefore, it is obvious that the existing low-voltage circuit breaker with a residual current trip device fails to satisfy the use requirements of the user on small size, low cost and high-current specification, and especially fails to satisfy the small-size and integrated use requirements proposed by more and more users on the low-voltage circuit breaker having a residual current trip device of which the current specification reaches 40A.

An objective of the present invention provides a low-voltage circuit breaker with a residual current trip device, which is small in size, compact in structure and more reasonable in layout, against the defects of the prior art, not only the rated current specification can be expanded to 40A, and meanwhile, it is unnecessary to increase the volume of a small-sized integrated circuit breaker, but also the assembly convenience of the product is improved.

To achieve the objective, the invention adopts the following technical solutions.

It is provided a low-voltage circuit breaker with a residual current trip device, wherein a plurality of circuit breaker poles which are arranged in parallel and the residual current trip device are arranged in a molded insulation shell <NUM>, each circuit breaker pole comprises a pair of input/output connecting terminals (<NUM> and <NUM>, <NUM> and <NUM>, <NUM> and <NUM>, and <NUM> and <NUM>), an electromagnetic trip device (<NUM> or <NUM>) sensitive to a short-circuit current, a thermal trip device (<NUM> or <NUM>) sensitive to an overload current, a static contact <NUM> fixed on an integrated molded case, a movable contact <NUM> in closing/breaking fit with the static contact, and an arc extinguishing device <NUM>, wherein the circuit breaker poles are uniformly arranged at the two sides of the residual current trip device, adjacent circuit breaker poles at each side share a composite operating mechanism which is used for controlling the on and off of two pairs of movable contacts and static contacts, and each composite operating mechanism is provided with a handle <NUM>, a rotation plate <NUM> provided with a contact connection mechanism for two movable contacts <NUM> of the two adjacent circuit breaker poles driven by the rotation plate <NUM>, a trip connection rod <NUM> pivotally arranged on the rotation plate <NUM> and a trip rod <NUM>. The residual current trip device comprises a residual current monitoring element, an electromagnetic relay <NUM>, an auxiliary trip mechanism with an auxiliary handle <NUM>, a rotation connection rod <NUM> mechanically coupled with each composite operating mechanism and a test loop <NUM>. A linkage element <NUM> is in mutual mechanical connection and linkage with the auxiliary handle <NUM> of the auxiliary trip mechanism of the residual current trip device and the handle <NUM> of each of the composite operating mechanisms at two sides. The circuit breaker further comprises a driving rod <NUM> which is in connection and linkage with the handle <NUM> of each of the composite operating mechanisms and the auxiliary handle <NUM> of the auxiliary trip mechanism of the residual current trip device.

As a further improvement of the present invention, four circuit breaker poles are provided, which constitute two pairs of circuit breaker poles in a pairwise combination manner, wherein two circuit breaker poles in each pair of circuit breaker poles share a composite operating mechanism, and the residual current trip device is arranged between the two pairs of circuit breaker poles in parallel; or three circuit breaker poles are provided, wherein two of the circuit breaker poles constitute a pair of circuit breaker poles in which two circuit breaker poles share a composite operating mechanism, the rest single circuit breaker pole uses an operating mechanism singly, and the residual current trip device is arranged between the pair of circuit breaker poles and the single circuit breaker pole in parallel.

As another further improvement of the present invention, the rotation connection rod <NUM> of the residual current trip device is provided with a mechanical coupling structure which can be in cooperative fit, that is mechanically coupled, with short-circuit trip stubs (<NUM> and <NUM>) of the composite operating mechanisms of the circuit breaker poles at the two adjacent sides at the same time.

As another improvement of the present invention, a plurality of parallel baffles are arranged inside the molded insulation shell <NUM>, a plurality of parallel chambers are formed inside the molded insulation shell <NUM> through the baffles, the residual current trip device is arranged inside the middle chamber, and the circuit breaker pole is arranged inside each of the chambers at two sides.

As another further improvement of the present invention, the handle <NUM> of each composite operating mechanism is pivotally arranged on the molded insulation shell <NUM>, the rotation plate <NUM> is pivotally arranged on the molded insulation shell <NUM>, a U-shaped rod <NUM> is in hinge connection with the handle <NUM> and the trip connection rod <NUM> respectively, a trip rod <NUM> pivotally arranged on the rotation plate <NUM> is provided with two short-circuit trip stubs (<NUM> and <NUM>) which are matched with two electromagnetic trip devices (<NUM> and <NUM>) of two adjacent circuit breaker poles controlled by the trip rod <NUM>, and is further provided with two overload trip stubs (<NUM> and <NUM>) which are matched with the two thermal trip devices (<NUM> and <NUM>) of the two adjacent circuit breaker poles controlled by the trip rod <NUM>, a mechanical interlock <NUM> is arranged between the trip connection rod <NUM> and the trip rod <NUM>, the elastic force of an energy storage spring is used for driving the composite operating mechanisms to trip, and the elastic force of a reset spring is used for driving the mechanical interlock <NUM> to lock.

As another further improvement of the present invention, the residual current monitoring element comprises an annular iron core <NUM>, a primary winding <NUM> which penetrates through the annular iron core <NUM> and is electrically connected with the circuit breaker poles, and a secondary winding wound on the annular iron core <NUM>, wherein the secondary winding is connected with an electromagnetic relay <NUM>, and the electromagnetic relay <NUM> is mechanical and cooperative action with the composite operating mechanisms of the circuit breaker poles at two sides through the auxiliary trip mechanism and the rotation connection rod <NUM>.

As another further improvement of the present invention, the auxiliary trip mechanism comprises an auxiliary handle <NUM>, an auxiliary U-shaped rod <NUM>, an auxiliary rotation plate <NUM>, an auxiliary trip rod <NUM>, a lock latch <NUM>, a reset lever <NUM>, an auxiliary energy storage spring and an auxiliary reset spring, wherein the lock latch <NUM> is mechanically coupled with the electromagnetic relay <NUM>, and the auxiliary rotation plate <NUM> is mechanically coupled with two short-circuit trip stubs (<NUM> and <NUM>) of the two composite operating mechanisms of the circuit breaker poles at two sides through the rotation connection rod <NUM>.

As a further improvement of the present invention, the primary winding of the residual current monitoring element is made of a flexible conductor which also serves as a flexible conductor of each circuit breaker pole, and one terminal of the flexible conductor is electrically connected with a corresponding outgoing terminal of the electromagnetic trip device (<NUM> or <NUM>) of the circuit breaker pole.

As a yet further improvement of the present invention, an opening for an electrical connection process is formed in the bottom of a corresponding position where the residual current trip device of the molded insulation shell <NUM> is arranged, and it is preferred that a detachable baffle block for mounting and debugging the electromagnetic relay <NUM> conveniently is arranged at the bottom of the electromagnetic relay <NUM>.

Proceeding from simplification of the product structure, the applicant performs an optimized design for the integrated layout and the specific structure of the low-voltage circuit breaker with a residual current trip device of the present invention, and therefore, a conductive loop of each circuit breaker pole is effectively reduced, the operation power consumption is reduced, the size of the circuit breaker in the width direction is reduced by nearly one third compared with a spliced product, and a valuable space is obtained for increasing the current specification and reducing the product volume at the same time. It is possible to promote the current specification to 40A on the premise of not increasing or reducing the volume, and an electromagnetic relay is arranged and debugged conveniently, the production process is optimized, the production efficiency is improved and the cost is reduced.

The advantages and features of the present invention will be seen more clearly from the description of the embodiments as shown in drawings, wherein:.

Specific embodiments of a low-voltage circuit breaker with a residual current trip device are further illustrated as below in conjunction with the embodiments illustrated in <FIG>. The low-voltage circuit breaker with the residual current trip device of the present invention is not limited to the description of the following embodiments.

The low-voltage circuit breaker with the residual current trip device of the present invention is illustrated mainly with a common three-pole four-line embodiment as shown in <FIG>, wherein referring to <FIG>, four pole modules constituting a circuit breaker unit and a residual current trip device are arranged in a molded insulation shell <NUM> and may be manufactured into a small-sized integrated low-voltage circuit breaker with a residual current trip device; a plurality of circuit breaker poles which are arranged in parallel and the residual current trip device are arranged in a molded insulation shell <NUM>, each circuit breaker pole comprises a pair of input/output connecting terminals (<NUM> and <NUM>, <NUM> and <NUM>, <NUM> and <NUM>, and <NUM> and <NUM>), an electromagnetic trip device (<NUM> or <NUM>) sensitive to a short-circuit current, a thermal trip device (<NUM> or <NUM>) sensitive to an overload current, a static contact <NUM> fixed on an integrated molded case, a movable contact <NUM> in closing/breaking fit with the static contact, and an arc extinguishing device <NUM>, wherein the circuit breaker poles are uniformly arranged at the two sides of the residual current trip device, adjacent circuit breaker poles at each side share a composite operating mechanism which is used for controlling the on and off of two pairs of movable contacts and static contacts, and each composite operating mechanism is provided with a handle <NUM>, a rotation plate <NUM> provided with a contact connection mechanism for two movable contacts <NUM> of the two adjacent circuit breaker poles driven by the rotation plate <NUM>, a trip connection rod <NUM> pivotally arranged on the rotation plate <NUM> and a trip rod <NUM>. One pair of adjacent circuit breaker poles share a composite operating mechanism which is used for controlling the on and off of the movable contact and the static contact, wherein manual operation means that handles <NUM> and <NUM> are driven by a linkage element <NUM>, and automatic operation means a cooperative action through the thermal trip device <NUM> or <NUM> (the remaining device is not shown) and the electromagnetic trip device <NUM> or <NUM> (the remaining device is not shown). The residual current trip device comprises a residual current monitoring element, an electromagnetic relay <NUM>, an auxiliary trip mechanism with an auxiliary handle <NUM>, a rotation connection rod <NUM> mechanically coupled with each composite operating mechanism and a test loop <NUM>. As specifically shown in <FIG>, the rotation connection rod <NUM> is provided with a mechanical coupling structure which can be matched with short-circuit trip stubs (<NUM> and <NUM>) of the composite operating mechanisms of the circuit breaker poles at two adjacent sides at the same time. A linkage element <NUM> is in mutual mechanical connection and linkage with the auxiliary handle <NUM> of the auxiliary trip mechanism of the residual current trip device and the handle <NUM> of each of the composite operating mechanisms at two sides.

The low-voltage circuit breaker with the residual current trip device of the present invention as shown in <FIG> comprises four circuit breaker poles having a protection function arranged in parallel, a residual current trip device and two composite operating mechanisms, which are arranged inside an integrated molded insulation shell <NUM>. These circuit breaker poles include four connecting terminals (<NUM> and <NUM>, <NUM> and <NUM>, <NUM> and <NUM>, and <NUM> and <NUM>) which can be used for controlling four paths of lines, that is, the four circuit breaker poles arranged in parallel include four pairs of connecting terminals, four electromagnetic trip devices, four thermal trip devices, four static contacts, four movable contacts and four arc extinguishing devices in total. The circuit breakers in such form may be in the following two actual use conditions: a three-pole four-line condition in which four paths of lines are three phases of live lines and one phase of neutral line respectively; and a four-pole condition in which four paths of lines are specific four poles respectively. In order to evade the difficulty to accurate description of poles in the circuit breaker caused by uncertainty of use conditions, the present application cites a term "circuit breaker pole" so as to accurately describe the concept related to poles in the circuit breaker preceding from the structure of the circuit breaker, that is: the "circuit breaker pole" described here refers to a combination of all the components configured on the same line controlled by the circuit breaker, and means one assembly, for example, a multi-pole circuit breaker having four circuit breaker poles, which can be used in a three-pole four-line or four-line circuit, or a multi-pole circuit breaker having three circuit breaker poles, which can be used in a two-pole three-line (live line, neutral line and ground line) or three-pole (three phases of live lines) circuit. The number of circuit breaker poles included in the embodiment of the low-voltage circuit breaker with the residual current trip device as shown in <FIG> is <NUM>, most commonly <NUM> and <NUM>. The number of the circuit breaker poles included in the low-voltage circuit breaker with the residual current trip device of the present invention is not limited to <NUM>, or may be <NUM>. The spliced structure of the prior art includes a circuit breaker unit and a molded shell, for example, a multi-pole circuit breaker which is formed by splicing four circuit breaker units and comprises a residual current trip function requires five molded cases. However, referring to <FIG> and <FIG>, only one integrated molded insulation shell <NUM> is available no matter how many circuit breaker poles are configured in the present invention, and therefore, the size of the circuit breaker in a width direction is reduced by nearly one third compared with an existing spliced product. For convenient installation and improvement of an insulated isolation performance, the molded insulation shell <NUM> is internally provided with a plurality of baffles (not shown in drawings) which are arranged in parallel, a plurality of parallel chambers are formed inside the molded insulation shell <NUM> through the baffles, the circuit breaker pole is arranged inside each of the chambers at two sides, and the residual current trip device is arranged inside the middle chamber. Obviously, each circuit breaker pole has the same structure, and therefore each chamber in which the circuit breaker pole is arranged has the same shape and size.

<FIG> and <FIG> illustrate an overall layout structure in which the residual current trip device is arranged in the middle of four circuit breaker poles arranged in parallel, wherein for a three-pole product, a pole A is adjacent to a pole B, and the residual current trip device is arranged between the poles AB and a pole C; and for a three-pole four-line or four-line product, a pole A is adjacent to a pole B, a pole C is adjacent to a pole N, and the poles AB and the poles CN are symmetrically distributed at two sides of the residual current trip device. Referring to <FIG>, <FIG> and <FIG>, the plurality of circuit breaker poles of the present invention are arranged inside the integrated molded insulation shell <NUM> in parallel, and the residual current trip device is arranged in the middle of the plurality of circuit breaker poles arranged in parallel, wherein the so-called middle is completely different from a structure where a residual current trip device of the prior art is arranged at one side (for example, at the right side) of a circuit breaker unit. In order to make wires in the circuit breaker be shortest and electrical connection be least, and meanwhile realize an effect that two circuit breaker poles share one composite operating mechanism, the so-called middle here further refers to the following optimal layout structure: in the event that four circuit breaker poles are included, the circuit breaker poles constitute two pairs of circuit breaker poles in a pairwise combination manner, wherein two circuit breaker poles in each pair of circuit breaker poles share one composite operating mechanism, and the residual current trip device is arranged between two pairs of circuit breaker poles arranged in parallel (as shown in <FIG> and <FIG>). In the event that three circuit breaker poles are included, two circuit breaker poles constitute a pair of circuit breaker poles and share one composite operating mechanism, and the remaining circuit breaker pole constitutes a single circuit breaker pole and uses an operating mechanism singly, and the residual current trip device is arranged between the pair of circuit breaker poles and the single circuit breaker in parallel. Obviously, an integral layout structure in which the residual current trip device is arranged in the middle of the plurality of circuit breaker poles arranged in parallel is a key means for increasing the current specification and reducing the product volume, but it is necessary to finish overall layout planning, structures of related parts and components (especially an operating mechanism), a wiring structure, and redesign and integrated optimized design of a control process and a transmission process converted among five states (closing, breaking, short-circuit trip, overload trip and residual current trip) in order to realize this overall layout structure.

Referring to <FIG>, <FIG>, <FIG>, <FIG> and <FIG>, the linkage element <NUM> is in connection and linkage with the handle <NUM> of each composite operating mechanism and the auxiliary handle <NUM> of the auxiliary trip mechanism of the residual current trip device, wherein such connection may be realized by a connection structure of a known form. The "enabling linkage of the handle <NUM> of each composite operating mechanism and the auxiliary handle <NUM> of the auxiliary trip mechanism" here refers that the action of any handle will drive all the remaining handles to act. The linkage element <NUM> is placed in a contact closing position and a contact breaking position of the circuit breaker in an artificial or mechanical manner, or automatically operates through a thermal trip device, an electromagnetic trip device or the residual current trip device. To improve the linkage performance among various circuit breaker poles and between each circuit breaker pole and the residual current trip device, the low-voltage circuit breaker with the residual current trip device of the present invention further comprises a driving rod <NUM> which is in connection and linkage with the handle <NUM> of each composite operating mechanism and the auxiliary handle <NUM> of the auxiliary trip mechanism of the residual current trip device. A specific connecting structure for the connection of the driving rod <NUM> here refers that: a rod hole (not shown in drawings) through which the driving rod <NUM> can be inserted is present in the handle <NUM> of each composite operating mechanism. The linkage between the handle <NUM> of each composite operating mechanism and the auxiliary handle <NUM> of the auxiliary trip mechanism by means of this connection refers that the action of any handle will drive all the remaining handles to act. In the event of more circuit breaker poles, it is more important to additionally arrange the driving rod <NUM>. Due to the adoption of the technology of handles <NUM> of the composite operating mechanisms, the number of the handles <NUM> can be greatly reduced, and therefore, it is very easy to install and debug the additionally arranged driving rod <NUM> compared to the prior art.

Referring to <FIG>, <FIG>, <FIG> and <FIG>, there may be a plurality of specific structure schemes of the composite operating mechanisms. A preferred scheme lies in that: each of the composite operating mechanisms comprises a handle <NUM> pivotally arranged on the molded insulation shell <NUM>, a rotation plate <NUM> pivotally arranged on the molded insulation shell <NUM>, a trip connection rod <NUM> pivotally arranged on the rotation plate <NUM>, a U-shaped rod <NUM> in joint connection with the handle <NUM> and the trip connection rod <NUM> respectively, a trip rod <NUM> pivotally arranged on the rotation plate <NUM>, an energy storage spring (not shown in drawings) and a reset spring (not shown in drawings), wherein a mechanical interlock <NUM> is arranged between the trip connection rod <NUM> and the trip rod <NUM>, the elastic force of the energy storage spring drives the operating mechanism to trip, and the elastic force of the reset spring drives the mechanical interlock <NUM> to lock. The rotation plate <NUM> is provided with a contact connection mechanism for two movable contacts <NUM> of the two adjacent circuit breaker poles driven by the rotation plate <NUM>. The trip rod <NUM> is provided with two short-circuit trip stubs (<NUM> and <NUM>) which are in cooperative fit with two electromagnetic trip devices <NUM> and <NUM> of the two adjacent circuit breaker poles controlled by the trip rod <NUM>. The trip rod <NUM> is further provided with two overload trip stubs (<NUM> and <NUM>) which are matched with two thermal trip devices (<NUM> and <NUM>) of the two adjacent circuit breaker poles controlled by the trip rod <NUM>. The principle and structure of the mechanical interlock <NUM> can be realized just by a known type, where conversion of locking and unlocking between the trip connection rod <NUM> and the trip rod <NUM> can be performed under the control of the trip rod <NUM>. The composite operating mechanism is allowed to perform a closing operation under a locked state, and the unlocking operation renders the composite operating mechanism to release and trip. A contact connection mechanism for mounting two movable contacts <NUM> on the rotation plate <NUM> is preferably a connection mechanism having an overturn function. The biggest difference from the prior art lies in that a rotation plate in the prior art is provided with a movable contact of one pole, while the rotation plate <NUM> in the present invention is provided with two movable contacts of two circuit breaker poles. The other difference from the prior art lies in that: a trip rod in the prior art is only matched with one electromagnetic trip device and one thermal trip device, while the trip rod <NUM> in the present invention are not only matched with two electromagnetic trip devices (<NUM> and <NUM>), but also matched with the two thermal trip devices (<NUM> and <NUM>).

Referring to <FIG> and <FIG>, there are a plurality of specific structure schemes of the auxiliary trip mechanism. A preferred scheme lies in that the auxiliary trip mechanism comprises an auxiliary handle <NUM>, an auxiliary U-shaped rod <NUM>, an auxiliary rotation plate <NUM>, an auxiliary trip rod <NUM>, a lock latch <NUM>, a reset lever <NUM>, an auxiliary energy storage spring (not shown in drawings) and an auxiliary reset spring (not shown in drawings). The structure and principle of the auxiliary structure are similar to those of the composite operating mechanism, with the following differences: no movable contact needs to be arranged on the auxiliary rotation plate <NUM>, the lock latch <NUM> is mechanically coupled with the electromagnetic relay <NUM>, and the auxiliary rotation plate <NUM> is mechanically coupled with two short-circuit trip stubs (<NUM> and <NUM>) of two composite operating mechanisms of the circuit breaker poles at two sides.

Referring to <FIG> and <FIG>, the residual current monitoring element comprises an annular iron core <NUM>, a primary winding <NUM> penetrating through the annular iron core <NUM>, and a secondary winding wound on the annular iron core <NUM>, wherein the primary winding <NUM> is electrically connected with the circuit breaker poles, the secondary winding is connected with the electromagnetic relay <NUM>, and the electromagnetic relay <NUM> is in mechanical and cooperative action with the composite operating mechanisms of the circuit breaker poles at two sides through the auxiliary trip mechanism and the rotation connection rod <NUM>. The primary winding of the residual current monitoring element is made of a flexible conductor, and the flexible conductor may serve as an electric connector between the electromagnetic trip device of each circuit breaker pole and the corresponding outgoing terminal, such that the assembly convenience of the product can be improved. One circuit breaker pole is equipped with one flexible conductor, wherein one terminal of each flexible conductor is connected with an outgoing terminal of the electromagnetic trip device (<NUM> or <NUM>)of the circuit breaker pole. Obviously, such electrical connection structure can realize optimized effects of shortest wiring distance and least electric connections. A preferred embodiment of the electrical connection of each circuit breaker pole is as illustrated in <FIG>, which makes the wiring distance and the electrical connection be further optimized.

Referring to <FIG>, to further optimize connection, installation and debugging processes, a preferred scheme is as follows: an opening for an electrical connection process is formed in the bottom of a position where the residual current trip device of the molded insulation shell <NUM> is arranged, and preferably, a detachable baffle block <NUM> is arranged at the bottom of a part of the electromagnetic relay <NUM> of the residual current trip device. After installation of the electromagnetic relay <NUM>, connection between the electromagnetic relay <NUM> and the secondary winding and parameter debugging are accomplished, the electromagnetic relay is slid and arranged in place through the opening, and then the opening is sealed by a baffle block <NUM>. The baffle block <NUM> may be detached, such that the electromagnetic relay can be mounted and debugged conveniently, and the production process is optimized. As shown in <FIG>. The residual current trip device is in mechanically cooperative action with the circuit breaker operating mechanisms <NUM> at two sides through the trip mechanism and the rotation connection rod <NUM>.

The operation process of the low-voltage circuit breaker with the residual current trip device of the present invention will be described.

When the circuit breaker is closed:
a manual or automatic device pushes the linkage element <NUM> clockwise to rotate to a closed position, the linkage element <NUM> drives the handles <NUM> and <NUM> to drive the U-shaped rod <NUM> and rotate the trip connection rod <NUM> about an axis anticlockwise, the trip connection rod <NUM> is coupled with the trip rod <NUM> to form a mechanical interlock <NUM>, and the linkage element <NUM> is further pushed to rotate the rotation plate <NUM> about an axis clockwise and drive a contact support to rotate together, such that the contacts <NUM> and <NUM> are in contact and at the closed position. In a process of pushing the linkage element <NUM> to rotate, the driving rod <NUM> coupled with the handles <NUM> and <NUM> drives the handle <NUM> of the residual current trip device to rotate about an axis clockwise to drive the U-shape rod <NUM> to rotate the trip rod <NUM> about an axis anticlockwise. The trip rod <NUM> is coupled with the lock latch <NUM> to form a mechanical interlock (not shown in drawings) and further push the linkage element <NUM> to rotate the rotation plate <NUM> about an axis clockwise. When movable and static contacts of each circuit breaker pole are in contact and at a closed position, the trip mechanism of the residual current trip device accomplishes energy storage and self-locking, an indication window <NUM> as shown in <FIG> displays white.

After the circuit breaker is off:
a manual or automatic device pushes the linkage element <NUM> anticlockwise to rotate to an off position, the handles <NUM> and <NUM> drive the U-shaped rod <NUM> and rotate the trip connection rod <NUM> about an axis clockwise, and meanwhile, the energy storage spring (not shown) of the operating mechanism releases energy, such that the rotation plate <NUM> rotates anticlockwise and drives a contact support to rotate together, such that the contacts <NUM> and <NUM> (the remaining contacts are not shown) are at the off position, as shown in <FIG>. The trip mechanism of the residual current trip device is at an energy storage state, and the indication window <NUM> displays white.

When a short-circuit current is present in a circuit, the electromagnetic device <NUM> or <NUM> acts, a mandril <NUM> or <NUM> moves rightward and pushes the trip rod stub <NUM> or <NUM> (the remaining stubs are not shown) to act, such that the trip rod <NUM> rotates about an axis anticlockwise, and the mechanical interlock <NUM> formed by the trip rod <NUM> and the trip connection rod <NUM> is unlocked, the energy storage spring releases energy, the rotation plate <NUM> and the handles <NUM> and <NUM> rotate at the same time anticlockwise and drive the contact support to rotate together, such that the contact <NUM> and <NUM> are at an off position. The trip mechanism of the residual current trip device is at an energy storage state, and the indication window <NUM> displays white.

When an overload current is present in a circuit, a bimetal sheet <NUM> (the remaining bimetal sheet is not shown) of a thermal circuit breaking device is bent and deformed to drive an actuating rod to move rightward and drive the trip rod <NUM> to rotate about an axis anticlockwise by matching with a stub <NUM> or <NUM> of the actuating rod <NUM>, such that the mechanical interlock <NUM> formed by the trip rod <NUM> and the trip connection rod <NUM> is unlocked, the energy storage spring releases energy, the rotation plate <NUM> and the handles <NUM> and <NUM> rotate at the same time anticlockwise and drive the contact support to rotate together, such that the contacts <NUM> and <NUM> are at an off position. The trip mechanism of the residual current trip device is at an energy storage state, and the indication window <NUM> displays white.

When a residual current is present in the circuit and an action value is reached or a testing button <NUM> is pushed to generate a residual current in a testing loop, an electric signal generated by the secondary winding of the residual current monitoring element makes the electromagnetic relay <NUM> to act, the mandril <NUM> is popped up to push the rest lever <NUM> to rotate about an axis <NUM> anticlockwise and push the lock latch <NUM> to rotate about an axis anticlockwise, such that the interlock formed by the release connection rod <NUM> and the lock latch <NUM> is unlocked. The energy storage spring releases energy, the rotation plate <NUM> and the handle <NUM> rotate anticlockwise at the same time. The rotation plate <NUM> drives the rotation connection rod <NUM> to rotate anticlockwise about an axis to drive the trip rod stub <NUM> (not shown in the other side) of the composite operating mechanism of the circuit breaker units at two sides to move rightward, and the contacts are at an off position. In a process that the rotation plate <NUM> rotates to an unloading position anticlockwise, a color marker integrated with the rotation plate turns from white corresponding to the indication window <NUM> to red, that is the indication window <NUM> as shown in <FIG> displays red.

Claim 1:
A low-voltage circuit breaker with a residual current trip device, wherein a plurality of circuit breaker poles which are arranged in parallel and the residual current trip device are arranged in a molded insulation shell (<NUM>), each circuit breaker pole comprises a pair of input/output connecting terminals (<NUM> and <NUM>, <NUM> and <NUM>, <NUM> and <NUM>, and <NUM> and <NUM>), an electromagnetic trip device (<NUM> or <NUM>) sensitive to a short-circuit current, a thermal trip device (<NUM> or <NUM>) sensitive to an overload current, a static contact (<NUM>) fixed on an integrated molded case, a movable contact (<NUM>) in closing/breaking fit with the static contact, and an arc extinguishing device (<NUM>), wherein
the circuit breaker poles are uniformly arranged at the two sides of the residual current trip device, adjacent circuit breaker poles at each side share a composite operating mechanism which is used for controlling the on and off of two pairs of movable contacts and static contacts, and each composite operating mechanism is provided with a handle (<NUM>), a rotation plate (<NUM>) provided with a contact connection mechanism for two movable contacts (<NUM>) of the two adjacent circuit breaker poles driven by the rotation plate (<NUM>), a trip connection rod (<NUM>) pivotally arranged on the rotation plate (<NUM>) and a trip rod (<NUM>);
the residual current trip device comprises a residual current monitoring element, an electromagnetic relay (<NUM>), an auxiliary trip mechanism with an auxiliary handle (<NUM>), a rotation connection rod (<NUM>) mechanically coupled with each composite operating mechanism and a test loop (<NUM>);
a linkage element (<NUM>) is in mutual mechanical connection and linkage with the auxiliary handle (<NUM>) of the auxiliary trip mechanism of the residual current trip device and the handle (<NUM>) of each of the composite operating mechanisms at two sides;
characterized in that the circuit breaker further comprises a driving rod (<NUM>) which is in connection and linkage with the handle (<NUM>) of each of the composite operating mechanisms and the auxiliary handle (<NUM>) of the auxiliary trip mechanism of the residual current trip device.