Branch for connecting a consumer

Abstract

The invention relates to a branch (200) for connecting a consumer (1000), wherein the branch (200) comprises a circuit breaker (150), a downstream contactor (180) and a connector (100) which forms an electrical connection between the circuit breaker (150) and the downstream contactor (180), - wherein the connector (100) is formed in one piece, has at least one sensor (200) and an evaluation unit (210) for the measured values ​​of the sensor (200), and has first contacts (101) to the power switch (150) and second contacts (102) to the downstream contactor (180) in the same plug-in direction u, characterized in that - the circuit breaker (150) has a Maglatch (130) for tripping the circuit breaker (150), which is integrated into a housing of the circuit breaker (150), - the connector (100) has a control unit (140) for controlling the Maglatch (130), and - the branch (200) has an interface (135) that forms a signal connection between the control unit (140) and the Maglatch (130).

Description

[0001] The invention relates to a branch for connecting a consumer, an electrical arrangement and an operating method.

[0002] WO 2008 / 113397 A1 (Siemens AG) dated September 25, 2008, describes a connecting element that electrically and mechanically connects a circuit breaker and a downstream contactor in a so-called consumer branch, also simply referred to as a branch. In this consumer branch, the circuit breaker performs protective functions such as fault protection, in particular short-circuit protection, and / or overload protection. Fault protection means that the circuit breaker disconnects the load so quickly in the event of a fault that major damage is prevented. The downstream contactor enables the operational switching of a load, such as a motor, within the consumer branch.

[0003] In contrast, the one-piece connector described in DE 10 2022 208 368 A1 (Siemens AG) dated February 22, 2024, has additional functionalities. Among other things, the connector has at least one sensor and an evaluation unit for the sensor's measured values. One embodiment of this connector is the SIRIUS 3RC7 link module from Siemens AG, which can be clicked between a circuit breaker, e.g., the SIRIUS 3RV2 from Siemens AG, and a contactor, e.g., the SIRIUS 3RT2 from Siemens AG.

[0004] In current solutions for complying with the safety integrity level SIL2 regarding "Safe Torque Off (STO)" in a consumer branch consisting of a circuit breaker and a downstream contactor, an undervoltage release is mounted laterally on the circuit breaker (STO = Safe Torque Off).

[0005] Fig. Figure 5 shows an exemplary embodiment. In order to safely disconnect a load 1000, e.g., an electric motor, from an electrical distribution network 2100 even in an emergency at safety integrity level SIL2, an emergency stop device 320 is installed in addition to a standard on / off switch 330 and monitored by a safety switching device 310, e.g., a SIRIUS 3SK2 safety switching device from Siemens AG. The safe disconnection of the load 1000 is achieved by a contactor 180. In the event of a failure of the contactor 180, the circuit breaker 150 is tripped as a fallback solution.

[0006] The operating principle is as follows: The safety switching device 310 monitors the emergency stop command device 320 via two channels and with cross-circuit protection. When the emergency stop command device 320 is activated, the safety switching device 310 opens the relay outputs and switches off the contactor 180 in a safety-oriented manner. See Chapter 4.4 “Combination of a contactor with a circuit breaker” on page 59 ff. and Figure 50: “Application example: Emergency stop shutdown up to SIL 2 or PL d with a SIRIUS 3SK1 safety switching device” in the brochure “Contactors in safety applications - Application guide”, SIRIUS Safety / SIRIUS Control, Siemens Industry Online Support, Article ID: 109807687, V1.1, 70 pages, dated 07 / 2023. ©Siemens AG 2023, https: / / support.industry.siemens.com / cs / ww / de / view / 109807687 and Siemens AG, Industry Online Support International, Application Example Article ID: 38472027, Article Date: September 24, 2013, “Emergency Stop Shutdown up to SIL 2 or PL d with a SIRIUS 3SK1 Safety Switching Device”, https: / / support.industry.siemens.com / cs / document / 38472027 / not-halt-abschaltung-bis-sil-2-bzw-pl-d-mit-einemsicherheitsschaltger%C3%A4t-sirius-3sk1?dti=0&lc=de-WW; accessed on July 3, 2024)

[0007] The circuit breaker 150 serves as a fallback solution if the contactor 180 fails to disconnect the load 1000 from the distribution network 2100 due to a fault. For this purpose, an undervoltage release 300 is connected to a delayed-off output of the safety switching device 310. In parallel, the undervoltage release 300 is supplied with voltage via an additional normally closed auxiliary contact of the contactor 180. After a set delay time, the normally closed auxiliary contact of the contactor 180 must be closed (the contactor must have dropped out) so that the undervoltage release 300 continues to be supplied with voltage. If the contacts of the contactor 180 are welded shut and the normally closed auxiliary contact remains open, the circuit breaker 150 will be tripped by the undervoltage release 300 after the set delay time has elapsed.It is therefore a single-channel architecture (contactor 180) with a specified fault response (circuit breaker 150).

[0008] The combination of the circuit breaker 150 and the undervoltage release 300, which is mounted laterally on the circuit breaker 150, has a combined width B2 that is greater than the single width B1 of the circuit breaker 150 alone: ​​B2 > B1. For example, the Siemens AG SIRIUS 3RV2 circuit breaker in sizes S00 and S0 has a single width of 45 mm, and the Siemens AG SIRIUS 3RV2902 undervoltage release has a width of 19 mm, so that the combination of both devices has a combined width of 64 mm. This combined width means that a user of a circuit breaker-undervoltage release combination required for SIL2 loses installation space in available feeder systems. Furthermore, the combined width precludes the possibility of mounting several consumer feeders side-by-side on a DIN rail.

[0009] It is therefore an object of the invention to provide a consumer branch comprising a circuit breaker and a contactor which complies with the safety integrity level SIL2 with regard to STO and whose width does not exceed that of the circuit breaker.

[0010] This problem is solved according to the invention by the branch according to claim 1. Advantageous embodiments of the branch according to the invention are specified in dependent claims 2 to 9. The problem is also solved according to the invention by an arrangement according to claim 10. The problem is also solved according to the invention by a method according to claim 11.

[0011] The consumer branch according to the invention, or branch for short, is used to connect an electrical consumer, such as an electric motor, to an electrical distribution network. The electrical distribution network comprises any electrical energy source that provides the electrical energy required to operate the consumer. "Connection" here refers to establishing and maintaining an electrical connection between an electrical consumer and an electrical distribution network, through which the electrical consumer, e.g., an electric motor, obtains electrical energy from the electrical distribution network, i.e., an electrical energy source (voltage source), so that it can be operated. This electrical connection forms the load current path, which is also referred to as the main current path. The branch comprises a circuit breaker, a downstream contactor, and a connector.The circuit breaker performs protective functions in the load branch, such as fault protection, in particular short-circuit and / or overload protection, i.e., protection against faults that can occur in the load current path. The downstream contactor enables the operational switching (on / off) of the load in the load branch. The connector forms an electrical connection between the circuit breaker and the downstream contactor; electrical energy is conducted from the electrical power source to the electrical load via this electrical connection (load current path).

[0012] The connector is a single piece and includes at least one sensor, in particular a current sensor and / or a voltage sensor for detecting current and / or voltage in the load current path, and an evaluation unit for the measured values ​​of the at least one sensor. The connector also has first contacts for the circuit breaker and second contacts for the downstream contactor in the same direction of travel.

[0013] The circuit breaker features a magnetic latch for tripping, which is integrated into the breaker housing. A magnetic latch is a magnet-based, electrically operated, and therefore remotely controlled, electromagnetic device for actuating a switching lock of the circuit breaker. The spring of the switching lock, whose energy is released to open mechanical contacts, can be tensioned via a tensioning mechanism, e.g., by means of a handle.

[0014] The connector incorporates a control unit for activating the Maglatch. In the event of a fault, the control unit, e.g., a microcontroller unit (MCU), activates the Maglatch with minimal energy, causing it to actuate a locking lever in the switch lock. This releases stored energy (e.g., the energy of a compressed mechanical spring), which in turn opens the mechanical contact system of the circuit breaker.

[0015] The branch has an interface that establishes a signal connection between the control unit and the Maglatch. This interface can include an electrical connector and signal lines between the circuit breaker and the connector, allowing a control signal to be transmitted from the control unit to the Maglatch. Alternatively, the interface can be wireless, for example, via a radio connection using common protocols such as ZigBee, WiFi, or others.

[0016] The advantage here is that a branch circuit can be implemented at safety integrity level SIL2 with a width that does not exceed that of the circuit breaker. The width of the branch circuit does not exceed that of the circuit breaker alone. The invention thus provides a consumer branch circuit, comprising a circuit breaker and a contactor, which maintains safety integrity level SIL2 with respect to STO (Safety Tolerance Operation) and whose width does not exceed that of the circuit breaker. In particular, the branch circuit can be implemented with a width of 45 mm for motors up to a power rating of 15 kW / 400 V.

[0017] A user of the branch can therefore utilize existing feed-in systems, such as the Siemens AG 3RV29 feed-in system, without any loss of space. Furthermore, it allows for installation in a busbar system, such as the Siemens AG 8US busbar system, as well as on a DIN rail in a close-to-close arrangement. The invention thus offers significant space savings in a user's control cabinet.

[0018] Another advantage of the invention is that the branch does not require an undervoltage release and does not require wiring from the safety switching device to the undervoltage release.

[0019] Furthermore, the invention allows for implementation via Profisafe, e.g. directly with an F-CPU (= Fail-safe CPU; CPU = Central Processing Unit).

[0020] Advantageous embodiments and further developments of the invention are specified in the dependent claims.

[0021] According to a preferred embodiment of the invention, the sensor is configured as a current measurement sensor, for example as a current transformer, and / or as a voltage measurement sensor. In this way, faults such as overload or short circuit in a load current path that runs through the electrical connection between the circuit breaker and the downstream contactor can be detected.

[0022] According to a preferred embodiment of the invention, the sensor is electrically arranged between the first contacts and the second contacts in or on the main circuit.

[0023] According to a preferred embodiment of the invention, the connector includes a control circuit for the downstream contactor. The connector can also include a communication interface. Furthermore, the connector can include a probe for the contactor position indicator. Finally, the connector can include a control circuit for a reversing contactor.

[0024] According to a preferred embodiment of the invention, the connector not only forms the electrical connection between the circuit breaker and the downstream contactor, but also a mechanical connection between the circuit breaker and the downstream contactor.

[0025] According to a preferred embodiment of the invention, the connector, the circuit breaker and the downstream contactor are connected to each other in a tool-bound manner.

[0026] According to a preferred embodiment of the invention, the circuit breaker is a starter protection switch without an overload function.

[0027] According to a preferred embodiment of the invention, an electric motor can be supplied as a consumer via the branch.

[0028] The arrangement consisting of a distribution network, a consumer and a branch according to the invention for switching a consumer according to claim 10 is such that the branch is arranged between the distribution network and the consumer.

[0029] The inventive method for operating a branch circuit according to the invention is such that, in the event of a fault, the control unit controls the Maglatch via the interface in order to cause the circuit breaker to trip.

[0030] The properties, features and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more easily understood in connection with the following description of the embodiments, which are explained in more detail in relation to the figures.

[0031] This shows: Fig. 1A and Fig. 1B a connector with a circuit breaker and a downstream contactor; Fig. 2 a connector; Fig. 3 a circuit breaker and a downstream contactor as well as a connector before assembly; Fig. 4 an arrangement consisting of a distribution network, a consumer and a branch according to the invention; Fig. 5 a known solution for maintaining the Safety Integrity Level SIL2 with respect to “Safe Tolerance Off (STO)” in a consumer branch; Fig. 6 a method for operating the branch according to the invention with a safety switching device; and Fig. 7 An application example for operating the branch according to the invention directly with an F-CPU via Profisafe.

[0032] In the Fig. 1A and Fig. Figure 1B shows an electrical connector 100 for a circuit breaker 150 and a downstream contactor 180. The connector 100 is formed in one piece, providing an electrical connection between the circuit breaker 150 and the downstream contactor 180 and including at least one sensor 220. Furthermore, the connector 100 includes an evaluation unit 210 for the measured values ​​of the sensor 220, and first electrical contacts 101 for the circuit breaker 150 and second electrical contacts 102 for the downstream contactor 180 in the same insertion direction.

[0033] In addition to the connector 100 and the circuit breaker 150 and the downstream contactor 180, a mechanical connecting element 160 can be provided, which distances the circuit breaker 150 from the downstream contactor 180 and can also serve as a support surface for the connector 100.

[0034] In the depictions of the Fig. 1A and Fig. 1B the connector 100 according to the invention is mounted on the circuit breaker 150 and on the downstream contactor 180.

[0035] The circuit breaker 150 features a Maglatch 130 for tripping the circuit breaker 150. The Maglatch 130 can be triggered by a tripping signal, thereby actuating a pre-tensioned locking mechanism of the circuit breaker 150. When the locking mechanism is actuated by the Maglatch, it releases stored energy, opening the mechanical contacts of the circuit breaker 150 and thus placing the circuit breaker 150 in a current-blocking state. The Maglatch 150 is integrated into the housing of the circuit breaker 150.

[0036] The connector 100 has a control unit 140, which is integrated into the housing of the connector 100 and serves to control the Maglatch 130. The control unit 140 can send a trigger signal to the Maglatch 130 via an interface 135, which forms a signal connection between the control unit 140 and the Maglatch 130, thereby triggering the Maglatch 150.

[0037] Fig. Figure 2 shows the connector 100 and the mechanical connecting element 160. The connector 100 comprises first contacts 101, through which the connector 100 can be electrically connected to the circuit breaker 150, and second contacts 102, through which the connector 100 can be electrically connected to the downstream contactor 180. The first contacts 101 and the second contacts 102 have the same insertion direction, which means that the connector 100 according to the invention can be connected to the circuit breaker 150 and the downstream contactor 180 simultaneously by a single assembly movement.

[0038] The sensor 220 of the connector 100 according to the invention can be configured as a current measurement sensor, for example as a current transformer, and / or as a voltage measurement sensor. The sensor 200 can be electrically arranged between the first contacts 101 and the second contacts 102 in or on the main circuit.

[0039] The connector 100 according to the invention can further comprise a control contact 110 for controlling the downstream contactor 180 and a communication interface 119. The communication interface 119 can, for example, be designed as a plug or a socket for a wired connection; alternatively, the communication interface 119 can establish a wireless radio connection using typical protocols such as Zigbee, WiFi, or others.

[0040] Further elements on the connector 100 according to the invention can be a probe 111 for a contactor position indicator and a control element 115 for controlling a reversing contactor.

[0041] In addition to the main circuit, the signal connection formed by the interface 135 between the control unit 140 and the Maglatch 130 can also run through the first contacts 101 of the connector 100. However, it is also possible that the interface 135 between the control unit 140 and the Maglatch 130 is formed by separate contacts, e.g., plug contacts, which are closed when the connector 100 is plugged into the circuit breaker 150.

[0042] Fig. Figure 3 shows the assembly of the connector 100 according to the invention on the circuit breaker 150 and the downstream contactor 180. Because the first contacts 101 and the second contacts 102 of the connector 100 are designed in the same insertion direction, the connector 100 according to the invention can be mounted on the circuit breaker 150 and the downstream contactor 180 with a single insertion movement. As shown in the illustration of the Fig. 3 means that the connector 100 can be pushed or plugged onto the circuit breaker 150 and the downstream contactor 180 in a movement to the left.

[0043] Fig. Figure 4 represents an arrangement 2000 consisting of an electrical distribution network 2100, a consumer 1000, and a branch circuit 200 for switching the consumer 1000. The branch circuit 200 comprises a circuit breaker 150, a downstream contactor 180, and a connector 100, wherein the connector 100 forms an electrical connection between the circuit breaker 150 and the downstream contactor 180.

[0044] The consumer 1000, for example an electric motor, is electrically connected to the downstream contactor 180. At least part of the electrical connection formed by the connector 100 between the circuit breaker 150 and the downstream contactor 180 forms a load current path through which electrical energy can be transported from the distribution network 2100 to the consumer 1000 in order to operate the consumer 1000.

[0045] The circuit breaker 150 has a Maglatch 130 for tripping the circuit breaker 150. The connector 100 comprises a sensor 220, an evaluation unit 210 for the measured values ​​of the sensor 220, and a control unit 140 for controlling the Maglatch 130. The Maglatch 130 can receive a tripping signal from the control unit 140 via an interface 135, which provides a signal connection between the control unit 140 and the Maglatch 130.

[0046] The branch 200 can be designed in such a way that the connector 100, the circuit breaker 150 and the downstream contactor 180 are connected to each other in a tool-bound manner.

[0047] In the arrangement 2000, the branch 200 is electrically arranged between the distribution network 2100 and the consumer 1000, in that the distribution network 2100 is electrically connected to the circuit breaker 150 and the consumer 1000 is electrically connected to the downstream contactor 180.

[0048] The electronics of connector 100, in particular the evaluation unit 210 and the control unit 140, and optionally also a sensor 220 containing electronic components, can be arranged within connector 100 in such a way that they are exposed to a relatively low and manageable temperature profile. This is the only way to make practical use of electronics in connector 100 or in branch 200.

[0049] The insertion direction of the main current terminals of connector 100, such as the first contacts 101 and the second contacts 102 of connector 100, is the same, at 90° to the device arrangement. All other electrical connections are also arranged in this same insertion direction, for example, the control contact 110 for controlling the downstream contactor 180. This is the only way to create a system that can be easily integrated into existing systems. Additionally, the contactor switching direction is the same as the insertion direction, which allows for simple but important monitoring of the contactor position via the monitoring plunger 111.

[0050] The front-facing connection to the circuit breaker 150 and the downstream contactor 180 allows for tolerance compensation in the branch circuit 200. This tolerance compensation can be easily and reliably achieved by bending open the first contacts 101 and the second contacts 102 for the main current path. Another advantage of this arrangement is that almost all existing accessories, such as all add-on modules, feed-in systems, etc., can continue to be used, thus avoiding an unnecessary increase in the carbon footprint of the branch circuit 200 according to the invention. Retrofitting the spring-loaded branch circuits is also possible.

[0051] Fig. Figure 6 illustrates a first method for operating the branch according to the invention, which uses a safety switching device 310, e.g. a SIRIUS 3SK2 from Siemens AG.

[0052] To ensure that a consumer 1000, e.g., an electric motor, can be safely disconnected from a distribution network 2100 at safety integrity level SIL2, even in an emergency, an emergency stop device 320 is installed in addition to a standard on / off switch 330 and monitored by a safety switching device 310, e.g., a SIRIUS 3SK2 from Siemens AG. Safe disconnection is achieved via a contactor 180. If the contactor 180 fails, the circuit breaker 150 trips. A starter protection circuit breaker without overload protection is sufficient as the circuit breaker.

[0053] The functionality is as follows: Normal operation: The safety switching device 310 monitors the emergency stop command device 320 via two channels and with cross-circuit protection. When the emergency stop command device 320 is activated, the safety switching device 310 opens the relay outputs and switches off the contactor 180 in a safety-oriented manner. Fault case: The circuit breaker 150 serves as a fault response, which only occurs in the event of a fault. The Maglatch 130 is supplied with voltage by a control unit 140 located in the connector 100. The Maglatch 130 is designed such that, in the event of an interruption in its power supply, it releases a spring accumulator, thereby triggering the switching lock of the circuit breaker 150. In this way, the known application (see Fig. 5) can be simulated using the undervoltage release.

[0054] At the latest after a set delay time, the normally closed auxiliary contact of contactor 180 must be closed (i.e., the contactor must have dropped out) so that the Maglatch 130 continues to be supplied with power. If the contacts of contactor 180 are welded shut, the connector 100 detects this via corresponding sensors, and the circuit breaker 150 is tripped by the Maglatch 130 after the set delay time has elapsed. This is therefore a single-channel architecture (contactor 180) with a specified fault response (circuit breaker 150).

[0055] The Maglatch 130 is armed by the electronic control unit 140, but the Maglatch 130 is triggered (released by interrupting the power supply).

[0056] Fig. Figure 7 illustrates another method for operating the branch according to the invention, which is implemented via Profisafe, e.g. directly with an F-CPU.

[0057] The ET200SP is available not only with "standard interface modules" for communication, to which the connector can be connected, but also with "safety-related interface modules." The safety-related interface module is connected to the connector, which, for example, has a PROFIsafe capability.

[0058] The connector can be integrated into the backplane bus of a Siemens AG ET200SP by connecting this module to the ET200SP system via communication using a flexible backplane bus extension. This makes the connector a fully integrated member of the Siemens AG SIMATIC product family (products for Totally Integrated Automation = TIA).

[0059] Fig.Figure 7 shows an application example for operating the branch circuit according to the invention directly with an F-CPU via Profisafe. A branch circuit 200, comprising a circuit breaker 150, a downstream contactor 180, and a connector 100, and a SIMATIC ET200SP 340 are mounted side by side on a DIN rail 360. The SIMATIC ET200SP 340 provides an F-CPU, i.e., a CPU for a fail-safe application. The SIMATIC ET200SP 340 and the connector 100 are connected by a patch cable 350.

[0060] The electronic control unit 140 and, via the control unit 140, the Maglatch 130 are controlled directly by the F-CPU of the SIMATIC ET200SP 340 via Profisafe. Reference symbol list 100 connectors 101 first contacts 102 second contacts 110 Control contact for the downstream contactor 111 Query plunger for a contactor position indicator 115 Control element for a reversing contactor 119 Communication interface 130 Maglatch 135 Interface 140 control unit of 130 150 circuit breakers 160 mechanical connecting element 180 Schütz 200 consumer branch, branch 210 evaluation unit 220 Sensor 300 undervoltage releases 310 Safety switching device 320 Emergency Stop Command Device 330 On / Off switches 340 SIMATIC ET 200SP 350 patch cables 360° DIN rail 1000 consumers 2000 order 2100 distribution network B1 width of 150, single width B2 width of 150 and 300 together, combined width QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2008 / 113397 A1

[0002] DE 10 2022 208 368 A1

[0003] Cited non-patent literature

[0000] Combination of a contactor with a circuit breaker” on page 59 ff. and Figure 50: “Application example: Emergency stop shutdown up to SIL 2 or PL d with a safety switching device SIRIUS 3SK1

[0006] "Protectives in safety applications - Application guide", SIRIUS Safety / SIRIUS Control, Siemens Industry Online Support, Article ID: 109807687, V1.1, 70 pages, Date 07 / 2023 ©Siemens AG 2023, https: / / support.industry.siemens.com / cs / ww / de / view / 109807687

[0006] Siemens AG, Industry Online Support International, Application Example Article ID: 38472027, Article Date: 24.09.2013, “Emergency Stop Shutdown up to SIL 2 or PL d with a SIRIUS 3SK1 Safety Switching Device”, https: / / support.industry.siemens.com / cs / document / 38472027 / not-halt-abschaltung-bis-sil-2-bzw-pl-d-mit-einemsicherheitsschaltger%C3%A4t-sirius-3sk1?dti=0&lc=de-WW; Accessed on 03.07.2024

[0006]

Images