SU5904A1 - Device to protect low current installations - Google Patents

Description

Devices are known for protecting low current installations from the effects of high current conductors, consisting of a non-earthed protective conductor and arranged parallel to the protected conductor of weak current. The protective wire has a very small apparent appearance. Comparison and tuning, for example ;, with the help of switched-on capacitors, at the frequency violation frequency. Then, due to a short circuit: with the lead-in, the conductor wire, the action of a disrupting current, appears, a relatively significant current. With such a device, the current in the protective conductor deviates in phase from the disturbing current not at an angle of 160 °, cancer is required, but natsr. (tfi tune-up), approximately 90 °, so the STO effect of the breaking wire on the protected low-current wire is not eliminated. The present invention has a solution to eliminate this non-residual. For this protective wire

It is taken of such a size that the voltages induced by it are shifted by almost 180 ° with respect to that induced by the breaking wire. Self-induction L of the protective conductor is chosen in comparison: with its ohmic resistance R yo; POSSIBILITY is large. In this case, the current arising in the protective conductor,

far behind the electric motor in phase; the induced force induced in it, for example, by a railway wire.

Since the electromotive cH.ia in the protective conductor is shifted by almost 90: from the disturbing current, and as the above-mentioned phase lag occurs (the current induced in the protective conductor is shifted relative to the interfering current by 180 °), the electromotive forces induced in the nip low current lead on the one hand interfering current, and on the other

the sides of the protective conductor wire, mutually destroyed.

 GonacHO data author experience has shown. for the purpose of meeting the intended purpose it suffices to observe the conditions:

  i 1P S

Increased self-induction in the protective conductor of the bridge shall be of a permanent nature, such as, for example, if the nuclear power supply system is arranged according to the Erarup system, but can also be achieved by switching on the self-induction coils in separate places of the protective conductor, for example, at its earthing. A very favorable result can be obtained if the additional chokes of the protective wire at the same time serve as secondary coils of the tracerformers, the primary windings of which are included in the ground (for example, railway) wire. In this case, the phase shift between the currents of both pradodes is 180 °. It is recommended to subdivide the secondary windings of transformers into sections, connected to the protective conductor, in order to regulate the strength of the current in the protective conductor, bringing it to such a magnitude that the compensation of the electromotive forces induced in the low current conductor by rail is obtained. current and current protective wire. In all forms of implementation, the protective conductor is located in the immediate vicinity of the protected conductors of low current, mainly in the middle of the beam, of the conductors. If we are talking about protected cables, then the protective wire can also be inside the cable as a special conductor, to which then suction transformers are connected. It is also possible to envisage several conversational or telegraphic veins as extra wires required in the cable, of which the required amount is switched on to compensate in parallel, while the rest can be used to the extent necessary for operation. .

The proposed device does not depend on iOT changing weather conditions (ground moisture).

FIG. I and 2 drawing s) bra sen. The proposed device and its modification.

FIG. 1 shows a shielded cable 1 of weak current, in the immediate vicinity of the conductors of which the protective wire 2 is located; It is recommended to include an additional self-induction in the form of coils 3 in the grounded– ends of the latter. Interference (for example, railway wire) is indicated by number 4.

FIG. 2 shows a device in which transformers are used, connected between the interfering and protective wires. Primary obmagvi transformers 5 are included in the interfering wire. 4, and the secondary ones - to the protective conductor 2 (it’s best to be back at the grounded ends). The secondary windings are provided with branches, in order to regulate the strength of the current in the protective conductor.

To improve the performance of the protective wire, it is recommended that erjo be extended beyond the shielding area.

Subject of pateng.

1. Device for protection of low current installations against the influence of wires of strong tOKa by means of a special protection wire characterized by the 7th, that when using katuphek self-induction or Erarup braid, self-induction L of the protective wire not electrically connected to the wire of a high current, the value is such that 5y with the lowest possible ohmic resistance jK of the wire, the ratio is not less than 10., k- ...

2 .; Ci described in paragraph 1 of the device use as a katusha of self-induction of secondary windings, so called. the suction tranferors included in the protective wire, the primary windings of the vacuum transformers are included in the high current wire.

8.: When characterized in n. 2. Device. Laying protective wire inside .. cable sheath.

4. With the device described in clause 3, the parallel inclusion of the weakly-grounded conductors of a weak current cable in suction transformers.

5, With the device described in paragraph 1.2, the use of transformers with a partitioned secondary frosting.

6. Modification of the device described in items 1-3, which consists in the fact that the protective wire is extended beyond the length of the cable, on which the inductive action of the high current wire occurs.

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