DE401966C - Safety circuit for the automatic shutdown of disturbed cable routes - Google Patents

Description

(B 107007

For the automatic shutdown of a disturbed cable section in the event of a breakdown It is already known to arrange auxiliary conductors around the head, one below the other and are slightly insulated from the conductor itself. However, under certain circumstances, a breakdown between the main conductor and the auxiliary conductors take place without the Main insulation of the cable is pierced.

This breakdown then brings about the shutdown of the line, and it's for one Recommissioning necessary so that the error is eliminated first.

In order to prevent ^{a disturbance from being caused by the arrangement 1 of} the auxiliary conductors in this way, according to the invention the circuit should be made in such a way that the auxiliary conductors, in contrast to known circuits, usually do not take part in the current conduction. They are connected to the main conductor, nmr at one point, for example only at the cable ends, so that in normal operation only the; Charging current flows in them. In the event of a breakdown to an adjacent wire or to the lead sheath, however, there is a short-circuit or earth-fault current which can cause the disturbed line to be switched off. That ^! can be done in that the connection between the main conductor and the individual auxiliary conductors is performed in a known manner via a relay, which directly or indirectly causes the shutdown.

In outer drawing; is the new circuit for a single-core cable illustrated under the assumption that two auxiliary conductors are present in a manner known per se, between which the main conductor lies, α is the main conductor, & ^{1 is} the one and b ^{2 is} the other auxiliary conductor. Between the two auxiliary. conductors b \ b ² and the main conductor α lies an insulating layer c, while! the main insulation d is located between the auxiliary 'conductors and the lead sheath ß . The auxiliary conductor b ¹ is connected to the conductor α via a relay f ¹ at one / end of the track to be monitored, the auxiliary conductor b ² via a relay ff at the other end. In undisturbed operation ^{, the currents flowing through 1} the relays Z ¹ and f ^{2 are} not sufficient to attract the armatures h ¹ and h ² . However, if, as indicated at g , between

see one of the auxiliary ladder and the outer ,. If a breakdown occurs in the cable sheathing, the current intensity in the relay associated with this auxiliary conductor increases in such a way that the armature is attracted. According to the drawing, the armature A ^{2 is} tightened, but the armature A ^{1 is} not. In the attracted place h? but an auxiliary circuit that can cause the disrupted cable route to be switched off.

Instead of two auxiliary conductors, any other number of auxiliary conductors can be used. If necessary, the purpose of the invention can also be achieved with only one auxiliary conductor.

Claims (3)

Patent Claims: i. Safety circuit zu_n automatic disconnection of disturbed cable routes, characterized in that the conductor [μ) is surrounded by auxiliary conductors (b ¹ , b ² ) which are only connected to it («.) On that side of the route to be monitored in the event of a breakdown via the auxiliary conductor, the line to be monitored is switched off. 2. Safety circuit according to Claimi, characterized by auxiliary conductors (b ¹ , δ ² ), 3 <j which are connected partly on one side, partly on the other side of the line to be monitored, each at opposite ends to the main conductor (a) . 3. Safety circuit according to claim 1 and 2, characterized in that the connection between the main conductor (a ~) and the auxiliary ^{conductors (δ 1} , δ ² ) via relay (/ ¹ J / ² ) is performed, which in the event of a fault Cause shutdown.