DE1463456B2

DE1463456B2 -

Info

Publication number: DE1463456B2
Application number: DE19631463456
Authority: DE
Priority date: 1963-04-13
Filing date: 1963-04-13
Publication date: 1970-09-10
Also published as: DE1463456A1

Claims

1 21 2

To monitor electrical cables, cables are provided, directly under or under and helical protective conductor known, which is to be arranged over the conductive coil. This Isosich around power cables, in the manner of a fusible material, is expediently selected so that it ladder, e.g. B. made of lead, tin or bismuth short circuit no permanent, good conductive bridge and forms 5 when heated above the permissible level. An acetate film or one on a poly-tape Reason of failure by melting a terephthalic acid ester base have proven to be suitable Trigger signal current, and it's about the over-proven. This film can, for example, between Monitoring of communication cables, with one for the coil and one for the current-carrying conductor Passage of moisture made permeable surrounding insulating sleeve to be arranged. The foil Plastic are provided. io can also be provided above the helix.

A ground fault protection circuit is already known. It is also possible to have several instead of one in the cable

Direction for insulated electrical lines, with layers immediately below or above the conductive one

to provide the individual cores of a cable individually from under-spiral.

connected to each other via a relay trip unit. The drawing serves for explanation. It shows
direction grounded protective conductors and together from 15 F i g. 1 a single-conductor cable in section with the monitoring conductor arranged in an insulated manner via an auxiliary voltage source and a sheath,
Relay trip device ^; Fig. 2 a four-wire cable in section, also surrounded by monitoring conductors:

Earth fault current must lead, as a braid with 20 F i g. 3 the circuit arrangement for monitoring

relatively large cross-section. a single core cable.

Another known protective device for electrical The current-carrying conductor 1 is of the insulating

trical device also makes use of the shell 2, over which the thin conductive coil

Monitoring circuit is arranged on one of the operating del 3. The outer shell is with 4

voltage derived auxiliary voltage to be connected, 25 and the thin film is denoted by 5. The Wen-

which, in the event of a fault, the device from supply 3 serves as a monitoring conductor,

line separates. The current-carrying conductor 1 is, as FIG. 3 shows

The object of the invention is to connect a circuit arrangement to the busbar 6 and to transmit the voltage to the contact wire for the monitoring conductor? to find a street of a cable where it is immediately 30 lane. The Wenvon the operating voltage of the del 3 to be monitored, which serves as a monitoring conductor, is fed via the series connection of the coil 8 of the cable and the drive during the contactor and the variable resistor 9 on the side both a short circuit of the cable and the busbar 6 and connected on which indicates an interruption. For this purpose, the side of the contact wire 7 is connected to earth; that the invention is based on a circuit arrangement, 35 contactor controls the cable switch 10.
where the monitoring conductor is inside the cable. In the event of a cable or line fault, the following cases can occur, for example, arranged on one cable and isolated from earth:
The monitoring conductor 3 is interrupted, the operating voltage is derived and by an element the circuit is then broken through the contactor and the voltage at the other end of the cable 40, which is connected to the earth, connected to the cable switch 10; the electricity consumer. controls the circuit that contains the cable switch in the coil '· of a contactor that has held the switched-on operating position. Controls the switch associated with the cable. According to the interruption of the monitoring circuit and the invention, one end of the cable is the over- the dropping of the contactor then opens the cable monitoring conductor over the switch for sufficient 45. * '-

Voltage reduction at rated current. In the case of a cable current consumer, the monitoring conductor comes directly to the potential of the cable conductor with a voltage breakdown. Then connected to the leading conductor of the cable; the contactor drops out as described above, because the monitoring conductor surrounds the two connection terminals of the contactor coil known per se, the conductors carrying the operating voltage come into 5 ° potential.
Open helix shape. With such an arrangement, the cable monitors itself during operation

the current flowing through the monitoring conductor - patent claim;

himself. The supervisor is in the .Damage-.-.-, ... ·.-.... ··

event reliably interrupted and thus the cable 55 open circuit configuration for a monitoring switch, if the wire insulation and / isolated disposed within the cable or over the gemeinsamen.Aderumhüllung.inner- against earth conductors of a cable on which a half of the _insulative: shell For example, within a cable end via a power consumer to a plastic sheath, a conductive coil derived from copper or aluminum, for example, which is derived from the operating voltage and which is present through minium, and 60 an element with reduced voltage and on the other, this coil is carried out in such a way that it is in the cable end is connected to earth, in the event of a short circuit at the short-circuit point of the power consumer interrupts the coil of a contactor. So that the helix contains, in the event of a short circuit, which is sure to interrupt the circuit connection associated with the cable, ter controls, characterized in that its cross section is at most 2 mm ² . 65 that one end of the cable of the supervision conductor

Often it can be advantageous to use at least one (3) over the current rating dimensioned for a sufficiently thin layer of a different type of insulating material, reduction at the rated current the insulating sleeve and / or the jacket of the consumer directly to the operating voltage

leading conductor (1) of the cable is connected and that the monitoring conductor (3) is known per se Way, the conductor (1) carrying the operating voltage surrounds it in the form of an open helix.

1 sheet of drawings