Insulation, Electrical

Insulation, Electrical

 

insulation intended to prevent formation of an electrical contact between parts of electrical-engineering equipment that are at differing potentials. Electrical insulation can be described in terms of electric strength, volume and surface resistance, dielectric loss, corona resistance, resistance to heat and cold, and mechanical strength.

The choice of dielectrics for electrical insulation depends on the operating conditions. For example, heat resistance is of decisive importance for the insulation of electric machines (generators and motors); in this case the insulation usually consists of mica. For the insulation of overhead power transmission lines, resistance to moisture and mechanical strength are of paramount importance; therefore, porcelain and glass are most suitable. In radio engineering equipment, electrical insulation usually consists of materials with minimum dielectric loss and maximum volume and surface resistance. Combination electrical insulation, which consists of mineral oil and of oil-impregnated cellulose (paper, cardboard, or pressboard), is used for transformers, electric capacitors, and cables.

The dimensions of insulation components are determined by the operating voltage of the installation and by the long-term strength of the electrical insulation for a specified period of service. If overvoltages (short-duration rises of voltage) can occur in an installation, the design and dimensions of the electrical insulation are also determined by the magnitude of possible over-voltages and by the short-term electrical strength.

REFERENCES

Bogoroditskii, N. P., V. V. Pasynkov, and B. M. Tareev. Elektrotekhni-cheskie materialy, 4th ed. Moscow-Leningrad, 1961.
Kozyrev, N. A. Izoliatsiia elektricheskikh mashin i melody ee ispylaniia. Moscow-Leningrad, 1962.
Artem’ev, D. E., N. N. Tikhodeev, and S. S. Shchur. Koordinatsiia izoliatsii linii elektroperedachi. Moscow-Leningrad, 1966.
Sapozhnikov, A. V. Urovni izoliatsii elektrooborudovaniia vysokogo na-priazheniia. Moscow, 1969.

D. V. RAZEVIG

References in periodicals archive ?
It includes: - Restructuring the administrative building (asbestos removal, insulation, electrical, heating, ventilation) about 1 500m - Partial restructuring of the building externship out restoration (insulation, electrical, heating, ventilation) about 500 meters carrsIl be concluded with the candidate a project management market including basic mission - sketch / Preliminary draft ............................
Tenders are invited for Renovation of the facade, roof, staircase, basement insulation, electrical system, partial replacement of windows and doors in the building on Dynasy 8 in Warsaw
The contract involves earthworks-vrd, civil engineering, metal pipe frame, coating of anti corrosion, insulation, electrical, instrumentation and automation, as well as the means of access and associated handling.
Install two new boilers insulation, electrical, controls, piping, set up per manufacture setting and all remaining work for a complete turn key project.
Remove/dispose of existing roofing materials (app 1150 SF) to include framing, gutters, downspouts, down to wall framing, a/c units, mounted lights, interior drop tile ceiling structure, insulation, electrical wiring & accessories coming into ceiling space down to main panel box.
Tenders are invited for Keerblue sbd kb3440 - 400 gallon mini-bulk tank triple wall containment system, constructed of uv8 protected polyethylene with r16 insulation, electrical bx, redundant heating system, mechanical overfill protection, primary and secondary tank vents, bluediver 3/4 hp submersible pump, anchor kit.
Removal of the existing deaerator, condensate return unit and water softening systems along with new pumps, small revisions to the water, steam and condensate piping systems, pipe insulation, electrical service and minor pneumatic and electric controls work.
Roofing, scaffolding work, plastering works, Screed works, metal works, carpentry, tile work, locking system, repainting, flooring, orientation system, Baureinigung, construction sign, Heizleitungsumverlegung, Heating, Refrigeration, Air Conditioning Equipment, Sanitary systems, measurement and control technology, heat and cold insulation, electrical, accent lighting , elevators, landscaping, laboratory technology, initial, MPG services.
work may involve the change of use of premises, namely - Alteration of housing or accommodation in lodge- Transformation of houses or other local housing- Extension or adaptation of local agency- Transformation in various local offices or health including VMC, heating, insulation, electrical and wiring for computers, anti-panic doors, security bars, fire protection, access ramps.
Tekfen Construction shall be responsible to do local detail engineering, supply project materials for civil, structural steel, piping, painting insulation, electrical, instrumentation and acid protection and lining works and undertake all construction, erection, precommissioning, commissioning, start up and performance testing works.
Work to be carried out will be excavation, Foundation of the building, Landscaping, Load bearing construction - according to static study of building permit, Insulation, Bricklaying, Coatings, Paintings, Flooring, Roof insulation, Electrical installations, Electromechanical installations wooden interior, Fire-resistant doors and windows, Wc and shower, Changing rooms, Radiators and cabinets, Restaurant and canteen design etc.
Demolition, Saw Cutting, Drilled Concrete Piers, Paving and Markings, Aggregates, Landscaping, Concrete (Supply, Pumping and Finishing), Rebar, Masonry, Metal Fabrication, Steel Erection, Metal and Membrane Roofing, Insulation, Doors, Overhead Doors, Skylights, Interior Walls & Ceilings, Flooring, Specialties, Coatings, HVAC, Mechanical Insulation, Electrical, P&I, Survey & Site Services.