SU1495899A1 - Device for overvoltage protection of communication cable - Google Patents

Abstract

This invention relates to a wireline technique. The purpose of the invention is to simplify service and improve the quality of the transmitted signal by reducing mutual and external interference. The presence of a sealed auxiliary cable 7 allows, if necessary, temporarily disconnecting the dischargers 4 for the period of testing or locating damage by high voltage without opening the coupling 2. Making the anodes of 9 dischargers 4 in the form of rods arranged coaxially to the cathode 5 and included in the cuts of the protected vectors cable 1, improves the quality of the transmitted signal. 1 hp ff. 1 il.

Description

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The invention relates to a wired communication technique and can be used to protect cables from multiple overvoltage pulses and from prolonged exposure to dangerous currents in the intermediate and final stages of lightning, as well as from Induced influences of other sources. electromagnetic fields.

j The purpose of the invention is to simplify the service and improve the quality of the transmitted signal by reducing the mutual and external interference of the device (a);

: FIG. 1 shows the design and electrical circuitry of the device for protecting the communication cable from overvoltage; in fig. 2 - thi-electrode construction 1) ardnik, longitudinal 1 section.

; The device (Fig. 1) contains a symmetrical communication cable 1, a standard cast iron coupling 2 and a lead coupling 3, inside which are installed five electrode arresters 4 in an amount equal to the number of quadruples of the cable 1. Cathodes 5 bits: non-linear resistor 6 And the output auxiliary cable 7 are connected to the sheath by a symmetrical cable 1. Cable 7 is sealed to 1 sleeve 2 by means of a plug 8. Anno- kbi 9 spark 4 are connected to the wires of Cable 1.

The electrode discharge 4 Kfig, 2) is made in the form of an insulating housing 10, through the end walls of which rod anodes 9 are passed, which are arranged around the circumference of the coaxial cathode 5 and form with it spark gaps.

The device works as follows.

When a surge voltage pulse 1 passes through the conductors of the cable 1 and its threshold is triggered by successively connected spark gaps of the arresters 4 with a non-linear resistor 6, the protection device operates and prevents the insulation of the cable cores from breakdown. After the passage of a pulse, the total applied voltage from the intermediate currents or the final stage of the discharge and the current of the remote power supply will be less than the disconnect voltage of the nonlinear resistor 6,

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which is chosen to be between 1000 and 1200 V. Thus, the protection device operates only for very short periods of time (usually no more than 250-300 μs) and the surfaces of the discharge electrodes 9 and 5 are not eroded, as in the case of long-term exposure to large amounts . To temporarily disconnect the device for the period of testing the insulation of cable 1 by a high voltage, disconnect the core of the output cable 7 from its shell, without opening the joints 2 and 3 with the arresters 4 and without relieving the pressure in the cable 1. To disconnect the arresters 4 you can either use hermetic switch, or just temporarily unsolder the core from

shell at the end of the cable 7.

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The proposed device for protecting the communication cable from overvoltages provides the following advantages: the presence of a sealed output auxiliary cable allows, if necessary, to temporarily disconnect the device's dischargers for the period of testing or locating damage by high voltage without opening the coupling, which greatly simplifies the maintenance of the device and cable line; The use of 5-electrode arresters reduces the level of mutual and external interference, due to which the quality of the transmitted information increases, this is achieved by excluding long TO-COPs. To the arrays, because the special design of the arrays allows them to be mounted in-standard-nk coupling sleeves. besides togr, rather than in portable containers, the technology of mounting couplings with dischargers is greatly facilitated and the necessary number of dischargers is reduced by four; The device reliably and with a minimum time lag protects the insulation of the cable from multiple pulse overvoltages and is timely disconnected when exposed to continuous currents that destroy the discharge electrodes.

Claims (2)

1. Device to protect the cable from overvoltage, containing arresters placed in the coupling, ano5149589 The cables are connected to the cable cores, and the cathodes are connected to the cable jacket, characterized in that, in order to control the service, the arresters are connected to the cable jacket by means of an auxiliary cable that has been inserted tightly out of the specified coupling and which has been completed to break at the end of the conductor from the cable sheath. 2. The device according to claim 1, characterized in that, in order to improve the quality of the transmitted signal by reducing mutual and external interference, the anodes of the arrays are arranged in the form of parallel rods passed through the ends of the arrester and located circumferentially coaxial to the cathode, the anodes of the dischargers are installed in the gap of the wires of the cable to be protected. Yu Phie.g