DE1251424B - Circuit with an insulation monitoring device for the insulation control of electrical consumer devices - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN W / 2W PATENT OFFICE

EDITORIAL

Int. Cl .:

Number:
File number:
Registration date:
Display day:

HOIh

H02h

German class: 21d3-2

K 58159 VIII b / 21 d3 January 17, 1966 October 5, 1967

The invention relates to a circuit with an insulation monitoring device for insulation control electrical consumer devices that are equipped with a protective conductor and a center conductor.

In order to prevent an insulation fault on an electrical consumer device Fault voltage and / or a fault current occurs and is transmitted to the operator, the electrical tools in general Protective devices such as fuses, circuit breakers, secured in such a way that when the Protective conductor with one phase, the device is switched off immediately. However, as experience has shown, it happens again and again that the protective devices do not function if there is a slight insulation fault step. ■. · ■

In order to be able to detect even minor insulation faults in good time, it is known to use an insulation monitoring device " to be provided for insulation control. Eiii such an insulation monitoring device, which is mostly is designed as a signaling device and emits optical or acoustic signals, but has some significant ones Disadvantage. First of all, the signaling device must be continuously monitored with a visual display, in order to immediately to notice the occurrence of a fault current and switch off the equipment. According to experience but the attention decreases when observing such a signal device for a long time, which is very much can have dangerous consequences. Acoustic signals are particularly light when there is noisy work overheard. If the insulation monitoring device itself is defective, there is insufficient protection given against fault current.

If an insulation monitoring device is available, it is also not possible to connect the protective conductor and to bridge the center conductor, which is desirable for some reasons, since then that Signal device would display continuously without fault current being present. Besides, it isn't It is possible to determine whether the protective conductor itself extends into the consumer device Is okay or defective.

This is where the invention ties in and proposes a circuit with an insulation monitoring device Insulation control of electrical consumer devices with protective conductor and center conductor in connection with Protective devices, such as fuses, to indicate a minor insulation fault in which the protective devices not yet come into function, which is characterized in that between the protective conductor and the center conductor, a switch is arranged, which is in at least two switch positions Circuit with an insulation monitoring device for electrical insulation control Consumer devices ...

Applicant:

Kirsch Bernhard,.

Trier-Biewer, Biewerer Str. 193

Named as inventor:

Bernhard Kirsch, Trier-Biewer -

is adjustable, namely a switch position for bridging the protective conductor and neutral conductor when switching off the insulation monitoring device at the same time and a second switch position for switching on the insulation monitoring device simultaneous interruption of the bridge between protective conductor and neutral conductor.

Preferably, the switch can also be set to a third switch position in which both Protective conductor and neutral conductor are bridged and the insulation monitoring device is switched on. Return springs are advantageously arranged in the switch, which activate the switch when the shift lever is released always return to the former position. In addition, another control device is arranged. net, which is used to determine the functionality of the Protective conductor between the grounding point and the consumer device is used. This control device can consist of a transformer and a display device, e.g. B. a lamp, an ammeter or the like., exist, the control device optionally with the housing of the consumer device or with can be connected to the grounding point.

Further details of the invention can be seen from the exemplary circuit diagram. According to this, a power generator, for example a generator 1, has in a known manner a protective conductor SL, a center conductor MP and three phase conductors R, S and T. Am. Generator is an insulation monitoring device 2 with display device. A consumer device 3, for example a motor or the like, is connected to the generator 1.

According to the invention, a switch 4, which can be set in three positions, is arranged between the protective conductor SL and the center conductor MP. In the first switch position, which results in the normal working position, the protective conductor SL and the center conductor MP are connected by a closed double contact S via?

■ .- ■ '■'. 709 650/159

bridges, while a contact 6, which connects the switch 4 to the insulation monitoring device, is open is how it can be seen in the circuit diagram.

In the second switch position, which is used to check whether a weak fault current is present is, but the fuse would not respond, the double contact 5 is open, so that the The bridging of the protective conductor and the center conductor is canceled. However, contact 6 is closed, Display device is functional. If you connect it to the housing of the implement, it will always be light up or display as long as the protective conductor is OK. Is the protective conductor against it defective, as indicated for example at 10, the connection is interrupted and the display device 8 fails.

With the help of the monitoring device according to the invention, all possibilities for the

so that the insulation monitoring device works ίο Even weak fault currents occur with correct

can kick.

In the third switch position, both the double contact 5 and the contact 6 are closed. This switch position is used to check whether the insulation monitoring device works properly.

Before starting work with an implement connected to the generator, the Switch to the third switch position and the functionality of the insulation monitoring device checked. Then set to the second switch position to see whether there is a weak fault current is. Only if this is not the case, you switch to the first switch position, which is the working position represents.

Of course, there is always the opportunity to switch on the Insulation monitoring device to check again whether the device is still OK, or whether in the meantime any source of fault current has arisen. On the other hand, it is not necessary to always have the monitoring device to be observed, as in the working position a; Fuse prevents suddenly occurring fault current can be dangerous for the operator.

By using a switch known per se, in which the second and third switch positions only remains as long as the shift lever is operated, but after releasing the shift lever this automatically in each case in the first switch position goes back, it is ensured that in any case the fuse to switch off the stronger fault current is switched on.

. A monitoring device as described, however, would fail if the protective conductor itself would be defective, since a fault current could then occur without the insulation monitoring device this indicated or the backup addressed. It is therefore advantageous to additionally have a control device to be provided for determining the functionality of the protective conductor.

According to the invention, this control device is attached to the generator (grounding point), with between Protective conductor and phase conductor, a transformer 7 is connected, which is used for low voltage for a display device 8 to be generated. This display device 8 can be designed as a lamp, ammeter or the like be. In addition, a lamp 9 can be provided for the low-voltage dial lighting.

This display device 8 is now optionally with the housing of the implement 3 or the housing of the Generator 1 can be connected. If you connect it to the housing of the generator, you can check whether that early detection of the device's operation, but the well-known protection against strong Fault current received.

Claims (6)

Patent claims: 1. Circuit with an insulation monitoring device for the insulation control of electrical consumer devices with protective conductor and center conductor in connection with protective devices, such as Fuses, to indicate a minor insulation fault in which the protective devices are still do not come into function, characterized in that between the protective conductor and the center conductor a switch is arranged, which can be set in at least two switch positions is, namely a switch position for bridging the protective conductor and neutral conductor when the insulation monitoring device is switched off at the same time. And a second switch position to switch on the insulation monitoring device monitoring device with simultaneous interruption of the bridge between protective conductor and Center conductor. 2. A circuit according to claim 1, characterized in that the switch can be adjusted to a third switch position in which both the protective conductor and the neutral conductor are bridged, and the insulation monitoring device is switched on. '-''"'. 3. Circuit according to claims 1 and 2, characterized in that return springs in the switch are arranged, the switch is always in the former when the lever is released Return position. 4. A circuit according to claim 1, characterized in that a further control device is arranged which is used to determine the functionality of the protective conductor between the grounding point and the consumer device. ^: 5. Circuit according to claim 4, characterized in that that the control device consists of a transformer and a display device, e.g. a lamp, an ammeter or the like, consists. 6. Circuit according to claim 4 or 5, characterized in that the control device can optionally be connected to the housing of the consumer device or to the grounding point. Documents considered: German Auslegeschrift No. 1044 240. 1 sheet of drawings