WO2018154373A1 - Ground connection monitoring - Google Patents

Abstract

The invention relates to a terminal block (10) for fixing to a grounded support rail (12). The terminal block comprises an insulating material housing, a first potential terminal (14) formed in the insulating material housing for the connection of a first conductor, a second potential terminal formed in the insulating material housing for the connection of a second conductor (16), a third potential terminal (18) formed in the insulating material housing for the connection to the grounded support rail, wherein the third potential terminal can be connected to the grounded support rail by fixing the terminal block to the grounded support rail, and a circuit (20) formed in the insulating material housing. The circuit has a first input, which is connected to the first potential terminal, a second input, which is connected to the second potential terminal, a third input, which is connected to the third potential terminal, and an output circuit. The circuit is configured to signal a grounding fault of the first potential terminal and a grounding fault of the second potential terminal via the output circuit.

Description

 Ground fault monitoring

AREA ^■ - ^■

The present invention relates to a ground fault monitoring. In particular, the present invention relates to an earth fault monitor integrated in a terminal block.

BACKGROUND

By occurrence of a ground fault, d. H. An unwanted (low-resistance) electrical connection between the phase conductor and earth conductor or neutral conductor and earth conductor can impair or damage the function of an electrical or electronic device. Therefore, devices that reduce the risk of a ground fault or reliably detect and signal an (imminent) ground fault are advantageous.

SUMMARY

The present invention provides this purpose a terminal with integrated ground fault detection for mounting on a grounded mounting rail ready. The modular terminal comprises an insulating material housing, a first potential terminal formed in the insulating housing for connecting a first conductor, a second potential terminal formed in the insulating housing for connecting a second conductor, a third potential terminal formed in the insulating housing for connection to the grounded DIN rail, wherein the third potential terminal is connected by fastening the Terminal block on the grounded mounting rail to the grounded DIN rail can be connected, and formed in the insulating housing circuit. The circuit has a first input connected to the first potential terminal, a second input connected to the second potential terminal, a third input connected to the third potential terminal, and an output circuit, the circuit configured to to signal a ground fault of the first potential terminal via the output circuit and the circuit to do so is set up to signal a ground fault of the second potential terminal via the output circuit.

In this context, the term "terminal block", as used in the description and the claims, in particular a module to understand that provides one or more terminal points for releasable electrical connection with a conductor, wherein the module with mechanical Furthermore, by the term "mounting rail" as used in the description and the claims, in particular a profile rail, i. H. to understand an elongated device with a substantially constant cross-section, which is provided with a means for attachment, for example. For snapping the modules (eg, a TS 35 DIN rail).

Furthermore, the term "insulating housing" as used in the specification and claims, in particular an enclosure (ie, a solid casing or sheath) of a material to understand, which in the material thickness used and at the voltages, In addition, the term "potential connection" as used in the description and the claims, in particular an electrical connection such as to understand a terminal contact through which connected to the terminal contact or at the terminal contact clamped conductors can be brought to a common potential.

Furthermore, the term "circuit" as used in the description and the claims, in particular an arrangement of interconnected (electrically) connected electrical and in particular electronic components to understand. Output "as used in the description and the claims, in particular terminals or interfaces to understand a circuit that is intended for connection to a power supply or (in the sense of a signal transmission) for connection to other circuits and are set up. In addition, the term "output circuit" as used in the specification and claims is to be understood in particular as one or more circuits whose input or inputs are connected to an output or outputs of a circuit, ie based on the potential or potentials of the circuit Output or the outputs are controlled.

Preferably, conductors are formed within the insulating housing, which connect the circuit with contact elements.

Preferably, the contact elements are formed on a circuit board and the conductors extend between the contact elements.

Preferably, the circuit comprises a first comparator circuit, the first comparator circuit being arranged, a first voltage derived from a first potential at the first potential terminal, having a third voltage derived from a third potential at the third potential terminal, to compare.

Preferably, the circuit comprises a second comparator circuit, wherein the second comparator circuit is arranged, a second voltage derived from a second potential at the second potential terminal, with the third voltage derived from the third potential at the third potential terminal, to compare.

Preferably, the first voltage and the second voltage clamp a voltage window and the circuit is configured to signal a ground fault of the first or second potential terminal via the output circuit when the third voltage is outside the voltage window.

In this case, the term "voltage window" as used in the description and the claims, in particular a voltage range to understand.

Preferably, the circuit has a voltage limiting circuit, wherein a first comparator input of the first comparator circuit a first comparator input of the first comparator circuit is connected to the voltage limiting circuit and the third input, and a third comparator input of the second comparator circuit is connected to the first input and the second input and a fourth comparator input of the second comparator circuit connected to the voltage limiting circuit and the third input.

Preferably, the first comparator input of the first comparator circuit is connected via at least a first adjustable resistor to the first input or the second input and / or the third comparator input of the second comparator connected via at least one second adjustable resistor to the first input or the second input ,

Here, the term "adjustable resistance" as used in the description and claims, in particular a component to understand the electrical resistance is manually or electronically adjustable.

Preferably, the voltage limiting circuit comprises two anti-serially connected Z-diodes.

Preferably, the Ausgangsbeschaltung comprises an optical element, which is at least partially disposed within the insulating housing.

In this case, the term "optical element" as used in the description and the claims, in particular a component to understand, which is adapted to emit optical signals.

Preferably, the output circuit comprises a communication interface for sending an error message to a network participant. .

In this case, the term "communication interface" as used in the description and claims, in particular a connection to understand one or more electrical conductors whose potentials are varied according to a communication protocol and data to be transmitted.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained below in the detailed description with reference to exemplary embodiments, reference being made to drawings in which:

Figure 1 is a schematic view of a terminal for attachment to a grounded mounting rail. and

Fig. 2 is a schematic view of an integrable in the terminal block circuit for the detection of ground faults.

In the drawings, the same or analogous elements are identified by identical reference numerals.

DETAILED DESCRIPTION

Fig. 1 shows a schematic cross-sectional view of a (disk-shaped) terminal 10, which is mounted on a grounded mounting rail 12. As shown in Fig. 1, the support rail 12 may be formed as a DIN rail, which engages for securing the terminal 10 in a T-shaped recess of the insulating housing 10 of the terminal. The T-shaped recess of the insulating housing makes it possible to position the terminal 10 on the mounting rail 12 in the longitudinal direction. Further, by providing a clamping between the terminal 10 and the support rail 12 in addition to the positive connection in the transverse direction, a non-positive connection in the longitudinal direction can be achieved, which prevents the mobility of the terminal 10 along the support rail 12.

In addition, one or both of the rear rail of the support rail 12 protrusions of the insulating material flexible and / or relative to the center of the terminal 10 (eg. In the vertical direction in Fig. 1) be slidably formed, so that the terminal block 10 on the rail 12 (in the vertical direction in Fig. L) can be raufed. In particular, the undercut projections may be formed barb-like. As a result, the ends of the support rail 12 when snapped (horizontally) pushed outwards and finally snap behind the latching support rail ends, whereby the terminal 10 can be mounted on the support rail 12 in the form of a form-fitting transversely and positioned in the longitudinal direction.

As shown schematically in Fig. 1, a plurality of potential terminals 14-18 are formed in the insulating material, for example, by means of spring terminals (eg. The potential connections 14-18 can, as shown in FIG. 1, be accessible through recesses in one side of the insulating housing, wherein the recesses can in principle be formed in any area of the insulating housing accessible after the rowing of further terminal blocks 10, such as, for example to the longitudinal direction of the support rail 12 parallel sides of the insulating material.

In particular, the recesses may be formed in one of the sides of the insulating material, which faces away from the support rail 12, such as. The support rail 12 opposite side. Furthermore, markings can be provided next to or in spatial proximity to the recesses, which indicate the potential with which the respective potential connection 14-18 is to be connected. For example. For example, markings may be provided which indicate which potential connection 14-18 is to be connected to a phase conductor and which potential connection 14-18 is to be connected to a neutral conductor.

The potential terminals 14-18 are for connecting various types of conductors, such as. Wire lines, rails, bridging elements (for connecting potential terminals lined-up terminal blocks 10), etc. formed. In particular, a first potential connection 14 designed in the insulating housing for connecting a first wire line and a second potential connection 16 formed in the insulating housing for connecting a second one. Formed wire line, wherein the first wire line, for example. a phase conductor and the second wire line represents a neutral conductor of a 24V power supply.

Furthermore, as shown in FIG. 2, the third potential connection 18 formed in the insulating housing is designed for connection to the earthed mounting rail 12. In particular, the third potential connection 18 is designed such that it is automatically connected to the earthed mounting rail 12 when fastening (or when snapping) the terminal 10 onto the earthed mounting rail 12, for example by means of a spring contact.

In the insulating housing, a circuit board is further arranged with a formed on the circuit board 20 for ground fault detection. Ground fault detection circuit 20 includes a first input 22 connected to first potential terminal 14, a second input 24 connected to second potential terminal 16, and a third input 26 connected to third potential terminal 18. The board may have traces that connect electrical or electronic components to contact pads to which leads (eg, wire leads) connected to the potential terminals 14-18 are soldered.

Furthermore, the circuit 20 for ground fault detection comprises an output circuit 28 via which a ground fault of the first potential terminal 14 or an earth fault of the second potential terminal 16 can be signaled. For this purpose, the output circuit 28 is connected to a first comparator circuit 30 and to a second comparator circuit 32.

The first comparator circuit 30 compares a first input voltage (ie, a voltage applied to a first input of the first comparator circuit 30) derived from a first potential at the first potential terminal 14 with a third input voltage applied to a second input of the first comparator circuit 30 derived from a third potential at the third potential terminal 18. Similarly, the second compares Comparator 32, a second input voltage derived from a second potential at the second potential terminal 16, with the third input voltage, which is derived from the third potential at the third potential terminal 18.

By a ground fault, the first potential or the second potential approaches the third potential. As a result, the first input voltage of the first comparator circuit 30 or the second input voltage of the second comparator circuit 32 shifts in the direction of the third input voltage. If the change in the first input voltage or the second input voltage is greater than the original distance to the third input voltage, the output signal of the respective comparator circuit 30 or 32 is inverted and the ground fault detected thereby.

The inverted output signal of the first comparator circuit 30 and the second comparator circuit 32 can be output from the output circuit 28 as an optical signal (eg. By means of one or two light-emitting diodes, LEDs). For example. For example, a light emitting diode may be connected to the first comparator circuit 30 and the second comparator circuit 32 through an OR gate so that the light emitting diode illuminates (or extinguishes) when there is a ground fault against phase conductors or neutral conductors the presence of a ground fault) can be interrogated or signaled via the communication interface 34 by a higher-level monitoring unit.

As shown in FIG. 2, the first voltage is derived from the potential at the first potential terminal 14 and a potential at a first conductor node 36, which is derived from the potential at the first potential terminal 14 and the potential at the second potential terminal 16. Similarly, the second voltage is derived from the potential at the second potential terminal 16 and also from the potential at the first conductor node 36. The first voltage and the second voltage thus span a voltage window which (for example, in the middle) lies in a region that passes through the first Potential terminal 14 voltage applied and the voltage applied to the second potential terminal 16 voltage is limited. ,

The third voltage is limited by a voltage limiting circuit 38 which is connected to the first conductor node 36. The voltage limiting circuit 38 is configured to maintain the third voltage within a predetermined voltage window by allowing the voltage limiting circuit 38 to make an electrically conductive (low resistance) connection to the first conductor node 36 when the third voltage is outside the voltage window. Further, the first conductor node 36 is connected through a resistor 40 to the third potential terminal 18, thereby achieving that a deviation between the ground potential and the potential derived from the potential at the first potential terminal 14 and the potential at the second potential terminal 16, compensated by equalizing currents becomes.

The circuit 20 for the detection of ground faults, shown schematically in FIG. 2, can also be used, for example, in a 24V network, wherein a voltage of + 12V is applied to the first conductor node 36, which, as shown in FIG can be generated by a voltage divider, which is connected to the first potential terminal 14, to which + 24V and to the second potential terminal 16, on which GND is applied. It should also be understood that the circuit 20 may also be used to detect ground faults at voltages other than 24V networks.

In addition to the first conductor node 36, the circuit 20 may also comprise a second conductor node, which via the voltage limiting circuit 38, which comprises, for example, two anti-serially connected Z diodes, to the first conductor node 36 and via a resistor to the third potential terminal 18 is connected.

A first input of the voltage comparator of the first comparator circuit 30 may further be connected via a resistor to the first potential terminal 14, and via a resistor to the first conductor node 36 connected. Furthermore, a second input of the voltage comparator of the first comparator circuit 30 may be connected via a resistor to the second conductor node. Similarly, a first input of the voltage comparator of the second comparator circuit 32 may be connected via a resistor to the second potential terminal 16 and via a resistor to the first conductor node 36. Furthermore, a second input of the voltage comparator of the second comparator circuit 32 may be connected via a resistor to the second conductor node. By adapting the resistors or by forming one or more of the resistors as adjustable resistors (for example as a potentiometer), the sensitivity of the ground fault detection can be adapted to the ground faults to be detected so that, for example, even ground faults or relatively high-impedance earth faults can be detected ,

If no ground fault, in the case of a 24V network at the first input of the first comparator circuit 30 are 18V, at the first input of the second comparator 32 6V and at the second inputs 12V. If an earth fault occurs, 12V are present at the first potential connection 14 or at the second potential connection 16. As a result, the voltage at the first input of the first comparator circuit 30 shifts below 12V or the voltage at the first input of the second comparator circuit 32 to above 12V, whereby the output signal of the respective voltage comparator is inverted. By the voltage limiting circuit 38, the voltage applied to the second conductor node is further limited to the range between 4V and 20V, whereby the voltage comparators are protected from overvoltages.

At the outputs of the voltage comparators semiconductor switches may be connected, which are closed by the inverted output signal of the respective voltage comparator. The closed semiconductor switches can result in an activation of the corresponding light-emitting diode and thereby to an optical display of the ground fault. Further, it is understood that instead of separate light-emitting diodes may also be provided a light-emitting diode, which is connected, for example, by means of an OR gate to the outputs of the voltage comparators.

LIST OF REFERENCE NUMBERS

10 terminal block

 12 mounting rail

 14 potential connection

 16 potential connection "

18 potential connection

 20 circuit

 22 entrance.

 24 entrance

 26 entrance

 28 output circuit

 30 comparator circuit

 32 comparator circuit

 34 communication interface

36 ladder nodes

 38 Voltage limiting switch

40 resistance

Claims

CLAIMS l. A terminal block (10) for mounting on a grounded DIN rail (12), comprising: an insulating housing; a first potential terminal (14) formed in the insulating housing for connecting a first conductor; a second potential terminal (16) formed in the insulating housing for connecting a second conductor; a third potential connection (18) formed in the insulating housing for connection to the earthed .Tragschiene (12), wherein the third potential closure (18) by attaching the terminal (10) on the grounded mounting rail (12) to the grounded mounting rail (12) is ahschließbar ; and a circuit (20) formed in the insulating housing, comprising: a first input (22) connected to the first potential terminal (14); a second input (24) connected to the second potential terminal (16); a third input (26) connected to the third potential terminal (18); and an output circuit (28); wherein the circuit (20) is adapted to signal a ground fault of the first potential terminal (14) via the output circuit (28); and wherein the circuit (20) is adapted to signal a ground fault of the second potential terminal (16) via the output circuit (28). Second terminal (ιο) according to claim l, wherein inside the insulating housing conductors are formed, which connect the circuit (20) with contact elements. 3. Terminal block (10) according to claim 2, wherein the contact elements are formed on a circuit board and the conductors extend between the contact elements. The terminal block (10) of any one of claims 1 to 3, wherein the circuit (20) comprises a first comparator circuit (30), the first comparator circuit (30) being arranged to derive a first voltage derived from a first potential at first potential equalization (14), with a third voltage derived from a third potential at the third potential junction (18). The terminal block (10) of claim 4, wherein the circuit (20) comprises a second comparator circuit (32), the second comparator circuit (32) being arranged to derive a second voltage derived from a second potential at the second potential junction (16 ), with the third voltage derived from the third potential at the third potential junction (18). The terminal block (10) of claim 5, wherein the first voltage and the second voltage span a voltage window and the circuit (20) is configured to ground a ground of the first or second Potential terminal (14, 16) via the output circuit (28) to signal when the third voltage is outside the voltage window. A terminal block (10) according to claim 5 or 6, wherein the circuit (20) comprises a voltage limiting circuit (38); wherein a first comparator input of the first comparator circuit (30) is connected to the first input (22) and the second input (24) and a second comparator input of the first comparator circuit (30) connected to the voltage limiting circuit (38) and the third input (26) is; and a third comparator input of the second comparator circuit (32) is connected to the first input (22) and the second input (24) and a fourth comparator input of the second comparator circuit (32) to the voltage limiting circuit (38) and the third input (26) " connected. The terminal block (10) of claim 7, wherein the first comparator input of the first comparator circuit (30) is connected to the first input (22) or the second input (24) via at least one first variable resistor; and / or the third comparator input of the second comparator circuit (32) is connected via at least one second adjustable resistor to the first input (22) or the second input (24). , , 9. Terminal block (10) according to any one of claims 1 to 8, wherein the output circuit (28) comprises an optical element which is at least partially disposed within the insulating housing. i 10. Terminal block (10) according to one of claims 1 to 9, wherein the output circuit (28) has a communication interface (34) for. Sending an error message to a network participant includes.