WO2016041839A1

WO2016041839A1 - Short circuiting device, particularly for arc flash protection in low and medium voltage installations

Info

Publication number: WO2016041839A1
Application number: PCT/EP2015/070713
Authority: WO
Inventors: Reinhold Kienlein; Markus HÖLLERL; Stefan DIETWEGER; Stefanie Schuster
Original assignee: Dehn + Söhne Gmbh + Co. Kg
Priority date: 2014-09-19
Filing date: 2015-09-10
Publication date: 2016-03-24
Also published as: EP3195341B1; DE102014016274A1; EP3195341A1; DK3195341T3

Abstract

The invention relates to a short circuiting device particularly for arc flash protection in low and medium voltage installations, consisting of a multi-part housing which receives a fixed and a displaceable electrode, said electrodes being held in the housing at a distance from one another by means of a sacrificial element. A mechanical prestressing element is also provided which acts upon said displaceable electrode and provides a force vector in the direction of the fixed electrode. Said prestressing element is located inside a head section of the housing. At least one ventilation and pressure compensation channel is also provided, as well as means for activating said sacrificial element such that the electrodes arrive in electrical contact with one another. According to the invention, a locking arrangement is designed in the head section of the housing and, following activation of the sacrificial element and establishment of contact between the electrodes, prevents the displaceable electrode from travelling back since said displaceable electrode can be directly blocked, or a slider following the movement of the displaceable electrode can be indirectly blocked, by means of a spring-loaded bolt.

Description

Short-circuiting device, in particular for arc fault protection in low and medium voltage installations

description

The invention relates to a short-circuiting device, in particular for the

Arc fault protection in low and medium voltage installations, consisting of a multi-part housing, which accommodates a fixed and a movable electrode, wherein the electrodes by a sacrificial element at a distance

held each other in the housing, a mechanical biasing element, which acts on the movable electrode and a force vector in

Direction of the fixed electrode bereitetesilt and which is located within a head portion of the housing, at least one venting and

Pressure equalization channel and means for activating the sacrificial element such that the electrodes come into electrical contact with each other, according to the preamble of claim 1 ...

From DE 10 2005048003 B4 a Kurzschließeinrichtong for use in low and medium voltage installations for property and personal protection is already known.

This short-circuiting device comprises a switching element, which from the

Trigger signal of an error detection device is actuated. Furthermore, there are two opposing contact electrodes with means for supplying current, wherein these can be contacted to a circuit with terminals of different potential. The contact electrodes are under mechanical bias such that in case of short circuit spring assisted relative movement of the electrodes is executed to each other.

A sacrificial element acts as a spacer between the contact electrodes. Moreover, there is an electrical connection between the sacrificial element and the switching element on the one hand and one of the contact electrodes on the other hand in order to bring about a thermal flow-induced thermal destruction of the sacrificial element in a targeted manner. According to DE 102005 048 003 B4 is the Victim element a thin-walled hollow cylinder with a ratio between diameter and wall thickness of the hollow cylinder> 10: 1, wherein the material of the hollow cylinder is made high-melting.

The known short-circuiter is used in personal protection equipment which is capable of on the basis of an arc detection

Trigger switching element. Such a teaching is shown in DE 10 2013 001 612 A1, where the energy for triggering the switching element is obtained there exclusively from the energy of the fault arc occurring.

In known short-circuiters, the contact surfaces of the electrodes are compressed by the residual spring force of the biasing spring in the tripped state.

Due to the high current density occurring at individual contact points there is a risk that the surface of the electrodes partially melts.

The resulting pressure between the contact surfaces, the biasing spring force can be overcome and the movable of the electrodes are pushed back. This in turn leads to a considerable electrode erosion and the duration of the current carrying capacity is reduced.

Known short-circuiters also do not have the possibility of state detection, so that metrological means are required to a

Assessment of the relevant device to make.

Another problem of known short-circuiters is that due to necessary pressure equalization channels burnup and melt get out, was usually the need for a housing to form a collecting space for such particles entails. This increases the required space of such a skilled Kurzschließers.

From the foregoing, it is therefore an object of the invention to provide a further developed short-circuiting device, in particular for the arc fault protection in low and medium voltage systems, which a full

Current carrying capacity over a longer period allows, which is also provided with an integrated status indicator and which about such a mechanical stability has that damage to the sensitive sacrificial element as a spacer during transport, storage and installation work can be excluded.

The object of the invention is achieved by the feature combination according to claim 1, wherein the dependent claims comprise at least expedient refinements and developments.

It is therefore assumed that a short-circuiting device, in particular for the arc fault protection in low and medium voltage systems, which consists of a multi-part housing, the housing accommodates both a fixed and a movable electrode, wherein the electrodes held by a sacrificial element at a distance from each other in the housing are. Furthermore, a mechanical biasing device, in particular a biasing element or a biasing spring is present, which acts on the movable electrode and provides a force vector in the direction of the fixed electrode.

In an alternative, of course, there is also the possibility of performing both electrodes movable with the aim of getting in contact with each other in the event of a short circuit.

In a preferred embodiment, the mechanical

Biasing element within a head portion of the housing. Furthermore, venting and pressure equalization channels and means for activating the sacrificial element are present such that the electrodes come into electrical contact with each other.

The sacrificial element is preferably designed as a fusible element, in particular as a fusible tube, and is connected to an electrical one

External contact in connection. A triggering of the sacrificial element via a switching device with the result that flows through the sacrificial element, a current that converts this into such a state that the effect of

Sacrificial element is removed as a spacer.

According to a first aspect of the invention is in the head of the housing a

Locking arrangement is formed, which after activating the

Victim element and Inkontaktgelangen the electrodes a retraction of the movable electrode is prevented by directly the movable electrode or indirectly a subsequent movement of the movable electrode slide can be blocked by a spring-biased bolt or similar means.

Thus, when the movable electrode has left its home position, the spring-biased pin is released and prevents the movable electrode from moving back and forth so that its position relative to the fixed electrode is locked and unchangeable.

In a preferred embodiment, the spring-biased pin is mounted in a complementary recess in the head of the housing, wherein the direction of movement of the bolt substantially perpendicular to the direction of movement of the movable electrode or one with the

Electrode connected slide is.

According to another idea of the invention, the aforementioned recess communicates with a viewing window in the housing to the position of the bolt and thus the state of the short-circuiting device to

visualize. For example, here the bolt can be colored or have colored sections. At the initial position of the bolt is in

View window, for example, a green mark recognizable. In the short circuit, i. in the case of activation of the device, the mark changes in the window z. B. towards the red.

To securely lock the position of the movable electrode in the

Trigger case, have both with the slide in

Contact coming bolt end as well as the slider at its bolt contact surface a wedge shape. The required self-locking is by the

Inclination angle of the wedge surfaces and optimized by the choice of materials of bolt, slide and bolt guide.

In the unsolved state of the bolt is the front side of the slider, whereby no additional, adverse pressure force acts on the sacrificial element.

As already mentioned, the sacrificial element can be designed as a melt spacer, starting from a foot part of the housing one, the Enamel Abstandsha! Ter encompassing annular wall or a corresponding annular wall is formed to prevent ingress of molten mass in the electrode gap,

According to a further aspect of the invention, the lead in the housing

located venting and pressure equalization channels to a formed in at least one housing part Abbrandauffangraum or one

corresponding Abbrandauffangkammer, wherein the relevant space or the chamber has a connection to the ambient atmosphere.

In accordance with the invention, the cross-section of the venting and pressure equalizing channels increases outwardly from the interior of the device

continuous or discontinuous too.

By the execution of the venting channels as described above, a quick pressure equalization is possible by the flow resistance is kept low. The erosion exit is limited, as part of the im

Short circuit case melting electrode material already in the

Venting channels with the local surface, especially in the case of a metallic surface, merges. A wetterer part of the burn-up is transported by the air flow in the respective Abbrandauffangraum or the corresponding chamber and collected there. According to one

preferred embodiment is the burn-up collecting space or

Abbrandauffangkammer executed as one or more blind holes.

In a preferred embodiment of the invention, the head portion of the housing is made of a conductive material, e.g. Copper material or a copper alloy, and has an electrical terminal tab, wherein the movable electrode is arranged in the interior of the head part and laterally encompassed and guided by the head part material.

Between the head part of the housing and a housing foot part, according to a supplementary aspect of the invention, a stabilizing and force-absorbing ring is clamped in such a way that undesired mechanical stresses occur

Force effects on the sacrificial element are avoidable. In known short-circuiters, the sacrificial element designed as a fusible element or a melting tube is already compressed in a fall from a small drop height to the connecting lugs. The desired dielectric strength is then no longer given. Particularly problematic is the fact that this damage externally can not be determined, Furthermore, also by or after the installation of mechanical forces from the outside acting directly on the sacrificial element, which is also disadvantageous.

In the teaching of the invention significantly larger loads, even larger allowable drop heights are possible. In particular, external forces are derived from the terminal lugs or busbars by the force-receiving ring according to the invention and do not act on the sensitive

Sacrificial element,

The invention will be explained below with reference to an embodiment and with the aid of figures.

Hereby show:

1 shows a longitudinal section through a short-circuiting device according to the invention with two-part housing and locking arrangement in the untripped condition.

Fig. 2 is a view similar to that of FIG. 1, but in the

triggered condition and

Fig. 3 is a detailed representation of the formation of ventilation faucets together

Abbrandauffangraum.

The short-circuiting device according to the embodiment starts from a multi-part housing. In particular, a housing head part 1, e.g.

consisting of copper, and a housing foot 2, e.g. formed of an insulating material.

Within the head part 1 is a movable electrode 3.

In the foot part 2, a fixed electrode 4 is arranged. The electrodes 3 and 4 are replaced by a sacrificial element 5, which z. B. is designed as a melting element, at a distance from each other in two-part

Housing held.

In addition, a mechanical biasing element, in particular a spring 6 is present, which acts on the movable electrode 3 and provides a force vector in the direction of the fixed electrode 4.

The spring 6 is located within the head part 1 and is supported, as it were, between the head part 1 and the movable electrode 3.

Furthermore, ventilation and pressure equalization channels 7 are provided and means for activating the sacrificial element 5 are formed. In particular, these means are a power supply 8. If the

Sacrificial element 5 is activated by appropriate current flow, it loses its mechanical support or its rigidity, so that the movable electrode 3 moves in the direction of the fixed electrode 4 and comes into contact with the latter, so that the desired short circuit between the

Connecting straps 9; 10 is created.

In the head part 1 of the short-circuiting device, a latching arrangement is formed, which after activating the sacrificial element 5 and contacting the electrodes 3; 4 prevents retraction of the movable electrode 3.

In this regard, according to the illustrated embodiment, a slider 11 is arranged to follow the movement of the movable electrode.

A spring-biased pin 12 can then, when the slider in the direction as shown in FIG. 2, lowers, penetrate into the remaining space and prevent retraction of the slide 1 1 and the electrode 3 respectively.

The spring-biased pin 12 is mounted in a respective recess in the head part 1 of the housing, wherein the direction of movement of the bolt 12 substantially perpendicular to the direction of movement of the movable

Electrode 3 is oriented. Fig. 2 shows the tripped state of the short-circuiting device with the clearly visible blocking function by the above-described locking arrangement. It can also be seen that the bolt 12 with the bolt spring 13 is subjected to a force.

The aforementioned recess communicates with a viewing window 14 in order to realize a status display 15. It is thus the position of the bolt 12 on the viewing window 14 from the outside visualized and recognizable »

The slider 11 is, as shown in FIG. 1 and 2, received by a Isolierhulse 16 and connected to the movable electrode 3.

The detail of Fig. 3 also makes it clear that both the coming into contact with the slide 1 1 bolt end 12 and the slider 1 1 at its pin contact surface have a wedge shape to cause the necessary self-locking.

The sacrificial element 5 is formed as a melt spacer, wherein, starting from the foot part 2 of the housing, a, the melt spacer encompassing wall or an annular wall 20 is formed to prevent penetration of molten material into the electrode gap.

The ventilation and pressure equalization channels 7 located in the housing lead to a combustion chamber formed in at least one housing part or a corresponding chamber 21. The combustion chamber or combustion chamber 21 can preferably be embodied as a blind hole.

The Abbrandauffangraum or the Abbrandauffangkammer 21 further has a connection 22 to the ambient atmosphere, which can be configured as an annular groove with a corresponding rotationally symmetrical design of the short-circuiting device.

It is in particular from FIG. 3 can be seen that the venting and pressure equalization channels 7 to the Abbrandauffangraum or to

Abbrandauffangkammer 21 cross-section side from the inside out

enlarge. As can be seen in the figures, a stabilizing and force-absorbing ring 23 is located between the head part 1 of the housing and the housing foot part 2. The ring 23 is braced between the head part 1 and the housing foot part 2 in such a way that undesired mechanical forces act on the body

Victim element 5 can be avoided.

According to the illustrated embodiment, a displacement of the movable electrode 3 in the tripped state is blocked on one side by the locking mechanism by one backlash. The travel time of the spring-biased locking bolt 12 is set on the interpretation of the bolt spring 13 and the corresponding masses so that the bolt rests against the shifter 11 due to short-circuit pressure. When triggered, the bolt 12 is moved according to the embodiment so that a visual

Change over the viewing window opening 14 is detected. Thus, the status display 15 is moved so far that it is no longer recognizable in the viewing window 14.

The integration of the Abbrandauffraum or Abbrandauffang- chambers in the housing component allows quick pressure equalization with low Abbrandaustritt. Furthermore, the entire

Reduced construction volume of the short-circuiting device.

Due to the solution of the stabilization of the overall arrangement under

Returning to the force-receiving ring 23, the device according to the invention protrudes fall heights <lm. A compression of the sacrificial element is clearly limited even at higher heights.

Claims

claims

1. Short-circuiting device, in particular for the arc fault protection in low and medium voltage installations, consisting of a multi-part housing, which receives a fixed (4) and movable (3) electrode, wherein the electrodes (3; 4) by a sacrificial element (5) at a distance

held to each other in the housing, a mechanical biasing member (6) acting on the movable electrode (3) and providing a force vector in the direction of the fixed electrode (4) and which is within a head portion (1) of the housing, at least one vent and pressure equalization channel (7) and means (8) for activating the sacrificial element (5) such that the electrodes (3; 4) come into electrical contact with each other,

characterized in that

in the head part (1) of the housing a Verriegelungsanord tion is formed, which after activating the sacrificial element (5) and Inkontaktgelangen the electrodes (3; 4) prevents retraction of the movable electrode (3) by directly the movable electrode (3) or indirectly one of

Movement of the movable electrode (3) following slide (11) by a spring-biased pin (12) can be blocked.

2. Short-circuiting device according to claim 1,

characterized in that

the spring-biased pin (12) is mounted in a recess in the head part (1) of the housing, wherein the direction of movement of the bolt (12) in the

Is oriented substantially perpendicular to B ^ ewegungsrichtung the movable electrode (3).

3. Short-circuiting device according to claim 2,

characterized in that

the recess is in communication with a viewing window (14) in the housing to visualize the position of the bolt (12) or a status indicator (15) and thus the state of the short-circuiting device.

4. Short-circuiting device according to one of the preceding claims, characterized in that both the bolt end which comes into contact with the slider (11) and the slider (11) have a wedge shape at its bolt contact surface,

5. Short-circuiting device according to one of the preceding claims, characterized in that

the sacrificial element (5) is formed as a melt spacer, wherein, starting from a foot part (2) of the housing, an annular wall or annular wall (20) embracing the molten spacer is formed in order to prevent penetration of molten material into the electrode gap;

6. Short-circuiting device according to one of the preceding claims, characterized in that

lead the located in the housing venting and pressure equalization channels (7) to a formed in at least one housing part Abbrandauffangraum or a Abbrandauffangkammer (21), wherein the relevant space or the relevant chamber (21) has a connection (22)

Has ambient atmosphere.

7. Short-circuiting device according to claim 6,

characterized in that

the cross-sectional area of the venting and pressure equalizing channels (7) increases from the inside to the outside.

8. Short-circuiting device according to one of the preceding claims, characterized in that

the head part (1) of the housing consists of a conductive material and has a connecting lug (10), wherein the movable electrode (3) is arranged inside the head part (1) and laterally encompassed and guided by head part material.

9. Short-circuiting device according to claim 8,

characterized in that

between the head part (1) of the housing and a housing foot part (2) a stabilizing and force-absorbing ring (23) is clamped, such that undesired mechanical forces acting on the sacrificial element

are avoidable.

10. Short-circuiting device according to one of claims 6 to 9, characterized g eken nzeich net that

the afterburner catchment chamber or the burn-up collecting chamber (21) is designed as one or more blind-hole bores.