Assessment of permissible tensile load during laying and operation of armored installation cable
The article reviews the investigation results of the performance of cables with protective elements (armor) in the form of a layer and a galvanized steel wire braid under the exposure to tensile loads using the example of modern installation and interface cables.
The consideration of this problem is especially important and unique due to the lack in the domestic and probably foreign literature of data concerning the change of transmission parameters of copper conductor cables under applied longitudinal tensile force.
The article presents the measurement results of the basic transmission parameters of cables with various designs and materials used; a brief interpretation of these results is given. In addition, a formula for the assessment of the ultimate tensile strength of armored cables is suggested, as well as recommendations are given for the establishment of standard ultimate tensile loads with respect to permissible critical deviations of electrical characteristics of cables during their installation and operation.
Installation cables; interface cables; armor; data transmission; tensile loads; direct burial.
Lebedev V.N., First Deputy General Director for Science, JSC «OKB KP»;
Matveev Yu.A., Chief Designer of Conductor Materials — Head of Conductor and Insulation Materials departament, JSC «OKB KP»
Prospects for improving conductor material characteristics in order to create lightweight heat-resistant wires and cables for aircraft and rocket and space equipment
The authors present basic characteristics and test results of bimetal and tri-metal wire based on copper and aluminum alloys with silver, nickel and copper coating under long-term exposure to elevated temperatures. This information is important for creation of lightweight and heat-resistant installation and aircraft wires. Based on the obtained results the authors make a conclusion about the prospective use of bimetal wire of aluminum alloys and tri-metal nickel and silver plated copper wire for onboard wiring.
Bimetal and tri-metal wire; mechanical characteristics of wire; electrical resistivity; diffusion layer depth.
Grin’ A.V., Leading Design Engineer, Estralin PS Ltd.;
Mneka A.S., Technical Director, Estralin PS Ltd.
Grounding of 110-500 kV lead-in cables for gas insulated switchgear and transformers
Grounding of shields of lead-in cables for gas insulated switchgear and transformers (as well as grounding of lead-in cables themselves) has some specific aspects related to both the design of the cables and the design and location of the gas insulated switchgear and transformers. The article summarizes the data on this issue obtained from the regulatory documents, information technical documents, catalogs, instructions and drawings of the lead-in cable manufacturers. Actual examples of grounding in various projects are presented.
110-500 kV cable systems; grounding of 110-500 kV cable shields; lead-in cables for gas insulated switchgear and transformers.