DE29713363U1 - Molded housing for an evaluation module for full motor protection - Google Patents

Description

Applicant: ESG Elektroschaltgeräte Görlitz GmbH Reichenbacher Straße 53-55 D-02827 Görlitz

Inventor: Dietmar Hoferichter Gersdorfstraße 02828 Görlitz

Andreas Ludwig Walter-Rathenau-Strasse 2! 02827 Görlitz

Günter Vondran Anton-Saefkow-Strasse 02827 Görlitz

Representative: Partnership ILBERG · WEIßFLOH Am Weißiger Bach 01747 Schönfeld-Weißig

Patent attorneys

Title: Moulded housing for an evaluation module for engine protection

Weissig, 26.07.1997

" * " 297030iDE/2 (10)

Description

Moulded housing for an evaluation module for full engine protection

The invention relates to a molded housing of a full motor protection module for a low-voltage circuit breaker, the switch lock of which is latched in the closed position with a shunt release that is actuated by an electronic evaluation device. Such an arrangement is known from DE 30 18 258 A1.

Low-voltage circuit breakers are switches with thermal current releases and with or without quick releases and are primarily used to protect motors against overloads or short circuits. As lock switches, they have switching-off properties. In addition, they can be operated manually using an ON/OFF control element and, if necessary, switched off remotely if they are equipped with a so-called shunt release. In the latter case, the circuit breaker is triggered by remote excitation of the shunt release's electromagnet, by a mechanical transmission element controlled by the magnet armature of the remotely excited electromagnet engaging the circuit breaker's switch lock and unlatching it.

Due to the mechanical loading of the switch lock, for example in the area of the latching point, it is necessary for the shunt release to be installed directly at a predetermined location on the circuit breaker, usually side by side with the switch lock board under a housing cap, which leaves the outer sides of the circuit breaker housing free in the direction of extension of the support rails for mounting auxiliary switches.

However, commercially available circuit breakers of the type described above do not offer any protection for speed-controlled motors, for example

* ** * 297030iEN/3(10)

This does not provide adequate protection, for example for asynchronous motors operated via converters. At reduced voltage, the current can remain below the setting value of the circuit breaker despite the motor rotor being blocked, so that the current thermal tripping devices, which are intended to simulate the heating characteristics of the motor, cannot respond or cannot respond in time. The motor gradually heats up more and more until the motor winding is ultimately destroyed.

For this reason, the only fully effective protection for speed-controlled drives is temperature monitoring in the motor itself. For this purpose, thermal contacts are built into the motor windings. If unacceptably high winding temperatures occur, the thermal contacts interrupt the control circuit of a full motor protection device, which disconnects the motor from the mains on all poles, e.g. via a contactor control, and prevents automatic restart as a result of the winding cooling down for reasons of operational safety.

In the aforementioned DE 30 18 258 Al, it has already been proposed, in order to significantly reduce the equipment and wiring effort, that the state of the thermal contacts in the motor windings be monitored by an evaluation electronics that is spatially housed in the shunt release and, when triggered, acts on it in the sense of unlatching and switching off the circuit breaker. This arrangement also makes it possible for the motor to start up again automatically after a power failure caused by the mains, unless an undervoltage release additionally attached to the switch lock board is intended to prevent this in the specific application of the motor.

However, the full motor protection implemented in this way requires a relatively voluminous housing for the additional module in question, which is why it is designed according to DE 30 18 258

t *

'•**_*^ _ ·« · 297030iDE/4{10)

Al is housed in an add-on housing that is mounted on the side of the circuit breaker intended for tripping.

For each size of circuit breaker in a series, suitable additional modules must therefore be designed, which makes them considerably more expensive when you consider that full motor protection is not yet desired by all customers, which results in higher production costs.

This also makes the circuit breaker wider, which can cause problems in systems with limited space and where several circuit breakers need to be installed. Ultimately, one mounting side is used for the installation of an auxiliary switch. However, it is sometimes desirable to provide auxiliary switches on both sides of the circuit breaker, for example for controlling larger systems, as fault signaling switches, fuse monitors, etc.

From DE 85 05 748 Ul an additional module for a circuit breaker with a shunt release is also known, which is intended for residual current monitoring and in whose housing the evaluation circuit and the shunt release are also combined. Essentially the same disadvantages apply here.

Furthermore, DE 295 08 611 Ul discloses a universal motor protection relay and an arrangement for this, which is characterized by the fact that a contactor can be snapped onto a universally applicable motor protection relay like onto a mounting rail. However, this document cannot provide any suggestions for a universally applicable full motor protection module.

The invention is based on the task of finding an arrangement that has the advantages of the aforementioned prior art, but is more flexible with regard to the conceivable

' 297030iEN/5(10)

is designed for a wide range of applications and is not tied to the connection geometry of a specific circuit breaker.

The object is achieved according to the invention by the features specified in claim 1. Advantageous embodiments are specified in the subclaims.

By accommodating the electronic tripping device in a separate module that can be mounted anywhere, the entire spectrum of a circuit breaker series can be covered with one module, regardless of the manufacturer and thus the appearance of the circuit breaker.

According to a preferred design, the evaluation device is housed on a circuit board in a housing adapted to the circuit breaker and can therefore be installed either to the right or left of the circuit breaker or at any other location in the electrical system. Since the evaluation device works regardless of position, the installation position can also be chosen freely.

Furthermore, in a further development of the invention, the electrical supply lines from the thermal contact of the motor winding, to the shunt release of the circuit breaker and to the voltage supply of the evaluation device are all laid below the envelope dimension (44 mm from the top edge of the top hat rail).

The invention will be explained in more detail using an embodiment and the accompanying drawing. The drawing shows

Fig. 1 a circuit breaker with a side-mounted evaluation module.

Fig. 2 shows the installation location

·«>*-*% - "' · ^# ' 297030iDE/6(10)

for the evaluation module.

Fig. 3 shows an opened module.

An evaluation module 2 is attached to the left side of a circuit breaker 1 according to Fig. 1. Connections 3 lead from the evaluation module 2 to the shunt release, which is not visible under the cover of the circuit breaker 1, and connections 4 lead from the three motor phases to the evaluation device of the evaluation module 2 for the purpose of supplying power. Furthermore, the connecting cables 5 to the thermal contact of the motor winding are shown. The option of also attaching the evaluation module 2' to the right side of the circuit breaker 1 is shown in dashed lines.

Fig. 2 symbolizes a variant according to which the evaluation module 2 can be arranged at any location and in any installation position. This means that both mounting sides of the circuit breaker 1 are available for the installation of auxiliary switches, etc., or the circuit breaker 1 can still find its place in spatially confined places in a distributor. At the same time, the great advantage becomes clear that the combination of circuit breaker 1 and evaluation module 2 is not tied to a specific size or design of the circuit breaker 1 and can therefore be used universally.

Fig. 3 shows how a molded housing 6 similar to an auxiliary switch housing can be used for the evaluation module 2. For this purpose, a circuit board 7 is used on which the electronic evaluation device is arranged. The connection pieces 8 in the molded housing 6 are now used for the electrical connection of the evaluation module 2 to the thermal contact of the motor winding on the one hand and the shunt release of the circuit breaker 1 on the other. In addition, connections 4 from the motor connection terminals of the circuit breaker 1 are led directly to the circuit board 7 within the envelope in order to supply the power for

· 297030iEN/7 (10)

to secure the evaluation device.

The molded housing 6 can be provided with contours for attachment to a circuit breaker 1, with openings for screw fastening and/or with a device for snap fastening to a mounting rail. The type and location of installation are almost arbitrary, since a mechanical connection to the circuit breaker's switch lock does not necessarily have to be established.

Reference symbol

1 low-voltage circuit breaker

2 Evaluation module

3 electrical connections

4 electrical connections

5 electrical connection cables

6 molded housing for the evaluation module

7 Circuit board in the evaluation module

8 connectors in the evaluation module

·· · 297030iEN/8(10)

Claims (6)

297030iDE/9(10) Claims 1. Moulded housing for an evaluation module for full motor protection, which contains a low-voltage circuit breaker, the switch lock of which is latched in the closed position with a shunt release, which is actuated by an electronic evaluation device, characterized in that the electronic evaluation device is housed in a separate module (2) which can be mounted as desired. 2. Moulded housing according to claim 1, characterized in that the electronic evaluation device is accommodated in a moulded housing (6) similar to an auxiliary switch with inserted connecting pieces (8). 3. Moulded housing according to claim 2, characterized in that the evaluation module (2) can be arranged optionally to the right or left of the low-voltage circuit breaker (1). 4. Molded housing according to claims 1 or 2, characterized in that the evaluation module (2) is arranged at any location and in any position in the electrical system. 5. Molded housing according to claims 1 or 2, characterized in that the evaluation module (2) can be used independently of the mechanical structure of the associated low-voltage circuit breaker (1). 6. Molded housing according to one of the preceding claims, characterized in that the electronic evaluation device is arranged on a circuit board (7). f*. Moulded housing according to one of the preceding claims, *···- ^# 1&thetas; -** * ** * 297030iEN/10(10) characterized in that the electrical supply lines from the thermal contact (19) of the motor winding, to the shunt release (17) of the circuit breaker (1) and to the voltage supply of the electronic evaluation device are led below the envelope dimension (44 mm from the top edge of the top hat rail) to the circuit breaker (1).