Electric four-wire cable
(57) Abstract:The invention solves the problem of creating a high-performance cable due to characteristics of the produced single-phase short circuit occurring due to the ferromagnetic component of the bimetallic PEN-conductor (zero), which redistribute the heat effect of the third conductive parts. In the electric four-wire cable, the fourth lived which has a reduced cross-section, is used as a PEN conductor (zero), the device is activated third conductive parts, PEN-conductor designed as a bimetallic conductor consisting of a conductive metal, such as copper or aluminum, and a ferromagnetic metal, for example steel. The heat of the fourth residential cable passing through the cable short circuit current, at low values of current is dissipated only the fourth residential cable, and with increasing short-circuit current is higher than the permissible (for the cable) scatters advanced conventional ferromagnetic core formed of a ferromagnetic part of the fourth conductor and a separate external design, shunting her. The invention relates to electrical engineering, preiudice energy at high power levels.Known electric four-wire cable, the fourth lived which has a smaller cross-section, is used as a PEN conductor (neutral) (manual edited Belorussia N. M., Energoatomizdat, 1987, S. 62). To protect from overheating PEN-conductor single-phase short circuit (OKZ) it is necessary to increase the cross section of this PEN-conductor, which creates technical and financial difficulties.The purpose of the invention is the creation of high-performance cable by taking into account characteristics is produced when OKZ arising due to the specially created redistribution of thermal effect of the third conductive parts.This objective is achieved in that in an electric four-wire cable of the fourth vein, having a smaller cross-section, is used as a PEN conductor (zero), together with a shunt sides of the conductive parts, and she lived made of bimetallic conductor metal, such as copper, aluminum, and ferrous metal, such as steel, the ratio of content which is derived from the dependency:
Al,Fe- electrical resistivity conductor (non-magnetic) and FEMA, i.e.,
where Sabout- the section of the PEN conductor;
Sf- the section of the phase conductor;
Sothe relative value of the current PEN-conductor made of conductive metal.Single-phase short circuit occurs a redistribution of heat from PEN-conductor, between the fourth and residential shokiruyushie third conductive parts.The heat of the fourth residential cable passing through the cable short circuit current, at low values of current is dissipated only the fourth residential cable, and with increasing short-circuit current is higher than the permissible (for the cable), scatters advanced conventional ferromagnetic core formed of a ferromagnetic part of the fourth conductor and a separate external design, shunting her.Conventional ferromagnetic core to its magnetic field interacts with passing through it an electric current and thus all involved in the dissipation of heat from the fourth residential cable in case of short circuit.Features produced bimetallic PEN-Explorer allow you to prevent exceeding the maximum allowable agreesto. Electric four-wire cable, the fourth lived which has a reduced cross-section, is used as a PEN conductor (zero), the device is activated third conductive parts, wherein the PEN-conductor made of bimetallic conductor metal, such as copper, aluminum, and ferrous metal, such as steel, the content of which is determined from the dependence of
< / BR>whereAl,Fe- electrical resistivity conductive, ferromagnetic metal, respectively;
the relative value of the lowest section of PEN-conductor, i.e.< / BR>where S0- the section of the PEN-conductor;
Sf- the section of the phase conductor;
the relative value of the current PEN-conductor made of conductive metal.
FIELD: power supply cables.
SUBSTANCE: proposed cable that can be used to supply with power electrical loads and at the same time to transmit telephone, television, computer, and radio communication signals has one or more similar sections incorporating central flat current-carrying conductor disposed between two flat insulating tapes, the latter being disposed, in their turn, between two flat neutral conductors whose width is greater than that of current-carrying conductor by double thickness of insulating tape.
EFFECT: enhanced conductivity and enlarged functional capabilities of cable.
1 cl, 2 dwg
FIELD: electronic engineering; gas panel manufacture.
SUBSTANCE: protective coating that can be used for manufacturing contact members of gas-panel strip conductors is formed on both sides of polyamide and applied by stenciling method using for the purpose dielectric composition resistant to 20-30% alkali solutions at temperature of 65 - 85oC that incorporates in its composition ethyl cellulose in the amount of maximum 9 parts by weight and organic solvent in the amount of minimum 91 parts by weight with boiling temperature of ≥ 190oC, minimal amount of ethyl cellulose and maximal amount of organic solvent being, respectively, 7.5 and 92.5 parts by weight.
EFFECT: improved rheological and protective properties of coating using proposed composition.
1 cl, 1 ex
FIELD: polymer materials.
SUBSTANCE: invention relates to novel liquid molding compositions comprising water-soluble or water-foaming polymer, which can be employed to improve water and moisture resistance as well as for waterproofing operation, for instance of waterproofing of cables. Composition contains water, water-soluble or water-foaming organic polymer obtained from monomer mixture containing 25 to 90 wt % of nonomer(s) selected from group including (meth)acrylamide and (meth)acrylic acid or salts thereof; 10 to 75 wt % of nonomer(s) selected from group including C8-C30-alkylethoxylated (meth)acrylamides, C8-C0-alkyl(meth)allyl ethers and C8-C30-alkylethoxylated (meth)allyl ethers; and water-miscible organic volatile liquid. Polymer is present in the form of discrete particles with average cross dimension below 10 μm. Invention further provides a method for improving water and moisture resistance of articles and/or preventing introduction of water into interior of article by way of contacting this article with above-indicated composition. Method of imparting waterproofing to outside or internal components of a cable comprises contacting at least one internal component with liquid molding composition. Invention allows preparation of composition capable of protecting fiber-optic cable.
EFFECT: enhanced waterproofing properties.
15 cl, 2 tbl, 11 ex
FIELD: cables for geophysical explorations.
SUBSTANCE: the cable has current conductors with an electric insulation of each conductor, multiple lays of the armor with a coating of plastic adhesive material. Each conductor is armored. The gaps between the armored conductors and the central part of the cable are filled with wires. The armored conductors and the wires are interweaved. The multiple lays of the amour are located on the interweaved armored conductors.
EFFECT: enhanced axial stiffness and efficiency of use.
5 cl, 1 dwg
FIELD: electrical engineering; electric cables for signaling, control, and data transfer and processing systems.
SUBSTANCE: cable has at least one pair of insulated and stranded current-carrying conductors and cable sheath. Insulating material is either halogen-containing polymer (polyvinyl chloride), or halogen-free polyolefin base material (polyethylene), or its copolymer. Insulation thickness is chosen from equation strand pitch is found from equation h = 25(2Δ + d), where d is conductor diameter; εr is relative dielectric constant of insulating material. With diameter of cable current-carrying conductors being enlarged, capacitance of cable pair was reduced (other characteristics being retained at desired level.
EFFECT: enhanced capacitance of working load on cable pair.
1 cl, 4 dwg, 1 tbl
FIELD: printed-circuit boards, multilayer conductors, and ribbon cables.
SUBSTANCE: proposed method involves spatial disposition of conducting communication lines which makes it possible to compensate for electromagnetic pickups in three-phase power circuits caused by self-induction and is based on compensating effect attained by superimposing electromagnetic inductances shifted in phase due to phase shift of currents carried by three adjacent conductors; novelty is that only positive (forward) currents carried by three adjacent layers and shifted in phase through 120 deg. are used in three-phase circuits. Passing three-phase current of same amplitude through three adjacent conducting tracks disposed strictly in parallel one on top of other in these three adjacent layers where columns built of conducting tracks occurring in three layers are formed we shall obtain equal-amplitude vectors in each layer using cyclic phase transfer; these vectors correspond to harmonic oscillations on vector diagram from all three phases (A, B, C).
EFFECT: maximized compensation of noise caused by self-induction.
4 cl, 3 dwg
FIELD: multiple twin cables for communications in local network.
SUBSTANCE: proposed multiple twin cable designed to prevent vapor transfer when immersed in petroleum oil has internal and external sheaths that cover insulated signal-transferring conductors and are made in the form of helical structure. Core filler fills up core and spaces between signal transferring conductors. Core filler and internal sheath are made of vapor-tight material and fixed to insulated conductors so that they fill up all grooves and slots around signal transferring conductors. External gas-tight sheath can be provided to make it possible to immerse cable in petroleum oil for long time intervals without impairing its functional capabilities.
EFFECT: ability of preventing vapor transfer lengthwise of cable.
26 cl, 4 dwg