EP2789062B1 - Surge arrester - Google Patents

Description

The invention relates to a surge arrester according to the preamble of claim 1.

It is known to form surge arresters as pluggable device combination of a lower part or housing base and a plug-in module or insert part. The housing base has connection terminals for contacting the electrical conductors and a receptacle for the insert part to be used, whereas at least one overvoltage protection element is arranged in the insert part. The electrical connection between the insert and the housing base is usually via plug contacts. In the insert part, an overvoltage protection element is arranged. Such surge arresters are each allowed for certain maximum dissipative currents. A disadvantage of such known surge arresters that the technical complexity of their implementation and the corresponding costs increase disproportionately with increasing maximum dissipatable current.

The DE 10 2007 042 991 A1 describes an overvoltage protection device, wherein in the U-shaped receptacle a plurality of protective elements can be arranged in parallel.

The WO 2008/003532 A1 describes a base part for receiving two surge arresters, which can be arranged parallel to each other in the U-shaped receptacle of the base part.

The DE 699 04 274 T2 describes a surge arrester, which has two varistors connected in parallel in one insert part, one of the two varistors serving as a reserve.

The publication "Improving current sharing between parallel varistors" (Putrus et al.) describes a possibility to improve the current sharing between parallel-connected varistors of the same type by connecting a low-resistance power resistor in series to each of the varistors.

The object of the invention is therefore to provide a surge arrester of the type mentioned, with which the mentioned disadvantages can be avoided, and with which easily and with little financial and technical effort safely high currents can be derived.

This is achieved by the features of claim 1 according to the invention.

This can be easily and with little financial and technical, especially manufacturing technology, effort a surge arrester are formed, which has a high current carrying capacity.

The subclaims relate to further advantageous embodiments of the invention.

It is hereby expressly referred to the wording of the claims, whereby the claims at this point are incorporated by reference into the description and are considered to be reproduced verbatim.

• Fig. 1 einen Überspannungsableiter in axonometrischer Darstellung;
• Fig. 2 ein Paket aus zwei Einsatzteilen in axonometrischer Darstellung; und
• Fig. 3 ein einzelner Einsatzteil in axonometrischer Darstellung.

The invention will be further described with reference to the accompanying drawings, in which a merely preferred embodiment is shown by way of example. Showing:

• Fig. 1 a surge arrester in axonometric representation;
• Fig. 2 a package of two inserts in axonometric representation; and
• Fig. 3 a single insert in axonometric representation.

Fig. 1 shows a surge arrester 1 comprising a device base (2) with a U-shaped insert receiving part 5, wherein the device base 2 is provided for attachment to a mounting rail, wherein in the insert part receptacle 5 at least two insert parts 3 are arranged, each of the insert parts 3 at least one overvoltage protection element having.

This can be simple and with little financial and technical, in particular manufacturing technology, effort a surge arrester 1 are formed, which has a high current carrying capacity.

Surge arresters 1 according to the invention serve to protect electrical installations and / or people from electrical overvoltages which propagate on an electrical line. In particular, the vulnerability but also the importance of computers has led to a widespread use of surge arresters 1. Surge arresters 1 are generally designed as components which produce a very high-resistance or insulating connection between at least one phase or an outer conductor of an electrical network, in particular an electrical supply network, and a neutral conductor or a further phase of the network , If no overvoltage occurs, virtually no current flows through the surge arrester 1, and the function of the subsequent network is not affected by the presence of the surge arrester 1. When an overvoltage occurs, the surge arrester 1 forms within a very short time a very low-impedance transition between the phase and the neutral conductor or another phase, and thus bypasses the subsequent network. For this purpose, the surge arrester 1 has at least one overvoltage protection element, which is preferably designed as a varistor. Due to the low resistance when an overvoltage occurs, correspondingly high currents can flow through the surge arrester 1.

Surge arresters 1 also have, in addition to a stated or specific nominal voltage, a specified or stated current-carrying capacity.

Surge arresters 1 according to the invention have a modular construction, and comprise a device base 2 and an insert part 3.

The device base 2 is provided for mounting on a mounting rail, such as a hat rail, and has for this purpose a corresponding mounting rail receptacle 25 and the necessary mounting means 26. For connection to the electrical network to be protected, the device base 2 has at least one first and one second connection terminal 27. The Fig. 1 shows a surge arrester 1 for the protection of a single-phase electrical network. The relevant surge arrester 1 has in each case two terminals 27 on the input side and on the output side. It can be provided to connect the two terminals 27 on one side in parallel, such as a distribution rail. However, it can also be provided that the two connection terminals 27 of one side in the device base 2 are short-circuited, so that in each case only one of the connection terminals 27 of one side has to be connected.

The device base 2 preferably has a multi-part device base housing 28, which is formed from an insulating material.

The device base 2 has a substantially U-shaped insert part receptacle 5 for the insert part 3, whereby a differently configured insert part receptacle 5 can be provided, for example in the form of a recess closed on the circumference. According to the preferred embodiment, the insert part receptacle 5 has a first and a second side part 13, 14, as well as a base part 20 connecting them, and is formed substantially opposite to a lower part 30 of the insert part 3, which is intended to be inserted into the insert part receptacle 5 to become. In the insert part receptacle 5, preferably in the region of the base part 20 are - also not shown - arranged inner contacts for contacting the insert part 3. In order to simplify the insertion of the insert part 3 into the insert part receptacle 5, an insertion region is preferably arranged on the first and / or second side part 13, 14.

The insert part 3 has according to the illustrated preferred embodiment, an insert part housing 4 made of an insulating material, which is preferably formed of several parts. The insert part housing 4 encloses the insert part 3 substantially completely and on all sides, wherein only the areas for contacting with the device base 2 as well as for display means are designed without insert parts. The insert 3 is designed as a fully functional electrotechnical component, and can be checked or removed as such electrotechnically. The insert part 3 furthermore has electrical contact pins 32, which protrude from the insert part housing 4, for making contact with the inner contacts of the device base 2.

It is envisaged that in the insert part receptacle 5 at least two insert parts 3 are arranged, wherein each of the insert parts 3 has at least one overvoltage protection element.

In a further consequence, an arrangement of a device base 2 and two insert parts 3 is essentially treated, as these also in Fig. 1 is shown. Surge arresters 1 with more than two insert parts 3 may also be provided, in particular with three or four insert parts 3.

The two insert parts 3 are each formed as a complete and functional insert parts 3, and in particular each have an insert part housing 4, which in each case also has a side wall, against which the two insert parts 3 abut each other. As a result, the two insert parts 3 are each independent electrical devices which can be removed as such or tested by a testing agency.

By a parallel connection of the at least two insert parts 3 can be achieved that the surge arrester 1 has a significantly higher current carrying capacity than a conventional surge arrester 1 with only one insert part 3. It is provided in this context that the overvoltage protection elements in each insert 3 each one Have higher current carrying capacity than the current carrying capacity of the entire surge arrester 1 divided by the number of inserts 3. The respective current carrying capacity is listed on the surge arrester. By the circuitry parallel arrangement of the overvoltage protection elements whose respective current load is reduced. Due to component tolerances, it will generally not come to a completely uniform distribution of the currents across the individual overvoltage protection elements even with identical specified component parameters. By increasing the respective current carrying capacity, this can be compensated advantageous.

In this connection, it is preferably provided that the overvoltage protection elements in the individual insert parts used are paired with regard to their parameters, in particular with regard to the turn-on voltage and the actual internal resistance. It is preferred provided to select and pair those overvoltage protection elements from a set of overvoltage protection elements, which have predeterminably small deviations of said parameters.

Preferably, as also shown, it is provided that the at least two insert parts 3 are arranged parallel to one another in the insert part receptacle 5. As a result, the space utilization within a distribution cabinet can be positively exploited. This also has an advantageous effect on the wiring of the two insert parts 3.

It can be provided that the two insert parts 3 are arranged in the insert part receptacle 5 as in each case physically separate insert parts 3. Therefore, the two insert parts 3 are not connected to each other. This is a particularly simple structure, with the use of standard components is particularly supported. It may be provided in this, as well as in the further context, preferably, that on a front side 35 of the at least two insert parts 3, a common cap 36 is arranged. As a result, the two insert parts can be held together and it is a uniform or holistic appearance supported.

It is preferably provided that the at least two insert parts 3 connected to each other, in particular riveted, are. It is provided in particular that the two insert parts 3 are connected after their separate completion. This can ensure that the respective insert parts 3 are not used in other surge arresters 1.

Each of the insert parts 3 preferably has in each case a function display 37, which indicates the functional readiness of the overvoltage protection element, and is coupled to it for this purpose. It is particularly preferred that the function displays 37 of the two separate insert parts 3 are coupled. This can be achieved that only a display informs a user about the operational readiness of the surge arrester. The function displays 37 are coupled in such a way that the failure of one of the overvoltage protection elements indicates an entire failure of the surge arrester 1, and an exchange of the insert parts 3 is required. This allows the Safety in electrical systems can be improved.

If a cap 36 is provided, it is preferably provided that the cap 36 has a viewing window 38, to view a function display 37. It is provided that the one function display 37 is visible, indicating the state of both overvoltage protection element.

Claims (7)

1. Surge arrester (1) comprising a device base (2) with a U-shaped insertion part receiver (5) wherein the device base (2) is provided to be fixed at an assembly rail, wherein in the insertion part receiver (5) are disposed at least two insertion parts (3), wherein each of the insertion parts (3) has at least one surge protection element, characterised in that the at least two insertion parts (3) are connected in parallel, and that the surge protection elements in the individual insertion parts (3) each have a higher current capacity than the current capacity of the entire surge arrester (1) divided by the number of the insertion parts (3).
2. Surge arrester (1) according to claim 1, characterised in that the at least two insertion parts (3) are disposed parallel next to one another in the insertion part receiver (5).
3. Surge arrester (1) according to one of claims 1 or 2, characterised in that on the front side (35) of the at least two insertion parts (3) is disposed a shared lid (36).
4. Surge arrester (1) according to one of claims 1 to 3, characterised in that the insertion parts (3) each have a function display (37) and that the function displays (37) are coupled.
5. Surge arrester (1) according to one of claims 3 or 4, characterised in that the lid (36) has a viewing window (38) for viewing a function display (37).
6. Surge arrester (1) according to one of claims 1 to 5, characterised in that the surge protection element is formed as a varistor.
7. Surge arrester (1) according to one of claims 1 to 6, characterised in that the at least two insertion parts (3) are connected with one another, in particular riveted.

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