Electrical materials. Wires. Scheme, description

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
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Electrical materials. Wires. Encyclopedia of radio electronics and electrical engineering

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Encyclopedia of radio electronics and electrical engineering / Electric installation work

by wire called a metal conductor of electric current, consisting of one or more conductive cores. A conductor consists of one (single-wire) or several wires (multi-wire) twisted together. Wires with stranded conductors are more flexible than wires with solid conductors.

Wire cores used in electrical installations are made of aluminum and copper. For reasons of economy, mainly wires with aluminum conductors are used.

Standard sections of current-carrying copper cores of wires: 0,5; 1; 1,5; 2,5; 4; 6; 10; 16; 25; 35; 50; 70; 95; 120; 150; 185; 240; 300; 400; 500; 800 mm2. Aluminum conductors of wires are made according to the same cross-sectional scale, starting from 2,5 mm.

Copper conductors with a cross section of up to 10 mm and aluminum conductors up to 25 mm are single-wire and multi-wire, conductors of large sections are only multi-wire.

Electrical materials. wires
Rice. 27. Wire designs: a - PV, APV; b - PPVS, APPVS, PPPS, APPPS; b - PPV, APPV, PPP, APP, APPR; d - PR, APR; e - PRD, PRD; e - PUNP; g - PRF, PRFl, APRF; 1 - conductive core; 2 - core insulation; 3 - separating base; 4 - cotton braid; 5 - braid for PRD from cotton yarn, for PRP from PVC compound; 6 - sheath made of PVC - plastic compound; 7 - winding with cotton yarn; 8 - twisting of cores and winding with paper yarn; 9 - a metal sheath with a folded seam made of AMC alloy or brass

Wires are bare (without insulation) and insulated. In an insulated wire, the conductive core is enclosed in a sheath made of rubber, polyvinyl chloride or vinyl plastic. To protect against mechanical damage and environmental influences, the insulation of some wire brands is covered with a cotton braid impregnated with an anti-rotten compound. The insulation of wires laid on vibrating mechanisms or in places where there is a risk of damage is additionally protected by a braid of galvanized steel wire.

Brands and characteristics of some wires:

A - bare, aluminum, stranded, core cross-section range, mm - 16-625;
AC - bare, aluminum, stranded, with a steel core made of galvanized wire, 16-400;
ACS - the same, 120-400;22
M - bare wire, copper, with a cross section of 4,6 and 10 mm, single-wire; 16 mm and above, stranded - 4-400;
PRG - wire with copper flexible conductor and rubber insulation, braided with cotton yarn, 0,75-400;
DPRG - flexible wire, two-core, with rubber insulation in a common braid of cotton fabric, 0,5-10.
PRF, APRF - copper PRF and aluminum APRF with one, two or three rubber-insulated cores wrapped in rubberized fabric and covered with a metal sheath, 1-4;
PRSHP - copper, with rubber insulation, wrapped with rubberized fabric, with the number of cores 1-3, 4-10, 5-30 sections, respectively, 1-95, 1-10, 1-2,5;
PRTO - copper, with rubber insulation, with impregnated cotton yarn braid, 1-120;
APRTO - the same, but aluminum, 2,5-400;
PV - wire with one copper core, with PVC insulation, 0,75-95;
PPV - flat wire, copper, inflexible, from 2-3 parallel cores, insulated and separated by PVC compound, 0,75-2,5;
PPGV - the same, with copper conductors, flexible, 0,75-2,5;
APPV - the same, with aluminum conductors, 2,5-6;
APV - aluminum with PVC insulation, 2,5-120.

Application and methods of laying bare and insulated wires:

wires of grades M, A, AS, ACS are used for laying overhead lines with voltage up to 1000 V and above; laying method - on insulators, reinforced on supports;
PR, APR - lighting and power networks inside and outside buildings, in fire hazardous rooms and in secondary circuits - in insulating tubes, on insulators, on concrete and metal surfaces with insulating materials laid under the wires;
PRG - connection of electrical machines, devices and instruments inside and outside buildings, laying on machines - in metal sleeves;
PV, APV - lighting and power networks indoors (dry, damp, especially damp, with vapors of mineral acids and alkalis) at an ambient temperature not exceeding +40 ° C, lighting boards, starting boxes, closed cabinets for secondary circuits - in tubes , on insulators, on metal and concrete surfaces with laying of insulating materials under the wires;
PGV - lighting and power networks, secondary circuits, wiring for machines and mechanisms in the presence of oils and emulsions - in tubes and metal sleeves;
PRTO, APRTO - lighting and power networks in explosion-proof rooms along the vibrating surfaces of machines, units and cranes and in cases where opening pipelines is very difficult, as well as in secondary circuits - in steel pipes and metal sleeves;
PRP, PRSHP - lighting and power networks, secondary circuits, electrical wiring of machine tools and mechanisms in the presence of mechanical influences on the wire and the absence of exposure to oils and emulsions on the wire - open with fastening with brackets;
PRF, APRF - lighting and power networks in dry rooms in the presence of a threat of light mechanical effects on the wire, as well as in cases where open wiring must be made invisible for architectural reasons - openly with brackets;
АР, АРД - charging of lighting fixtures in dry rooms at a voltage of up to 220 V between the cores in the event that flexibility is not required from the wires - inside and above the lighting fixtures;
DPRG - charging lighting fixtures outside buildings and in damp rooms at voltages up to 220 V in the event that the wires must be flexible - inside the lighting fixtures;
PPV, APPV - lighting wiring inside dry and damp rooms along walls and ceilings in networks with a rated voltage of up to 500 V - open with fixing with nails or staples;
APPVS - wiring in dry and damp rooms in networks with voltage up to 660 V - hidden laying under plaster.

Author: Bannikov E.A.

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