471:
960:
375:
298:. Polyimide insulated magnet wire is capable of operation at up to 250 °C (482 °F). The insulation of thicker square or rectangular magnet wire is often augmented by wrapping it with a high-temperature polyimide or fiberglass tape, and completed windings are often vacuum impregnated with an insulating varnish to improve insulation strength and long-term reliability of the winding.
36:
556:
surface quality so that insulating enamels do not break down under voltage. Good ductility is essential for the strip to be formed and packed while good strength is needed to withstand the high electro-mechanical stresses set up under occasional short-circuit conditions. Copper winding wires in transformers are compatible with all modern insulation materials, such as
526:
159:
350:
Smaller diameter magnet wire usually has a round cross-section. This kind of wire is used for things such as electric guitar pickups. Thicker magnet wire is often square, rectangular or hexagonal (with rounded corners) in cross section, packing more efficiently and having greater structural stability
497:
Because of its high electrical conductivity, copper is commonly used in coil windings, bearings, collectors, brushes, and connectors of motors, including the highest quality motors. Copper's greater conductivity versus other materials enhances the electrical energy efficiency of motors. For example,
563:
A major engineering reason to choose copper windings over aluminium is space considerations. This is because a copper-wound transformer can be made smaller than aluminium transformers. To obtain equal ratings in aluminium transformers, a 66% larger cross-sectional area is required than for copper
505:
One of the design elements of premium motors is the reduction of heat losses due to the electrical resistance of conductors. To improve the electrical energy efficiency of induction-type motors, load loss can be reduced by increasing the cross section of copper coils. A high efficiency motor will
485:
and current-carrying conductors. Electric motors are found in numerous diverse applications, such as fans, blowers, pumps, machines, household appliances, power tools, and disk drives. The very largest electric motors with ratings in the thousands of kilowatts are used in such applications as the
555:
Copper used for the manufacture of transformer windings is in the form of wire for small products and strip for larger equipment. For small products, the wire must be strong enough to be wound without breakage, yet flexible enough to provide close-packed windings. Strip products must be of good
544:
is a device that transfers electrical energy from one circuit to another through its coils (windings). The properties needed for motor windings are similar to those needed for transformers, but with the additional requirement to withstand mechanical vibration and centrifugal forces at operating
397:. At lower temperatures the service life of the wire is longer (about a factor of two for every 10 °C lower temperature). Common temperature classes are 105 °C (221 °F), 130 °C (266 °F), 155 °C (311 °F), 180 °C (356 °F) and 220 °C (428 °F).
551:
In North
America, aluminium is the predominant choice of winding material for low-voltage, dry-type transformers larger than 15 kilovolt-amperes (kVA). In most other areas of the world, copper is the predominant winding material. Purchasing decisions are generally a function of loss valuations
246:
Aluminium magnet wire is sometimes used as an alternative for large transformers and motors, mainly for economical reasons. Because of its lower electrical conductivity, aluminium wire requires a 1.6-times larger cross sectional area than a copper wire to achieve comparable DC resistance.
235:
The most suitable materials for magnet wire applications are unalloyed pure metals, particularly copper. When factors such as chemical, physical, and mechanical property requirements are considered, copper is considered the first choice conductor for magnet wire.
493:
to produce the required magnetic fields. For a given size of motor frame, high conductivity material reduces the energy loss due to coil resistance. Poorer conductors generate more waste heat when transferring electrical energy into kinetic energy.
567:
Connectivity is another important benefit of copper-wound transformers, as the oxide coating on the surface of aluminum makes soldering or otherwise connecting with it more difficult. Cleaning and brushing with a quality joint compound to prevent
516:
There are, however, disadvantages in increasing the electrical efficiency of motors through larger windings. This increases motor size and cost, which may not be desirable in applications such as appliances and in automobiles.
405:
In practice, maximum current density can vary from 2.5 A/mm for a wire isolated from free air to 6 A/mm for a wire in free air. If the wire is carrying high frequency currents (above 10 kHz), the
502:, manufacturers invariably use copper as the conducting material in windings. Aluminium is an alternate material in smaller horsepower motors, especially when motors are not used continuously.
513:
windings. This made sense since electrical losses typically account for more than half of all energy losses, and stator losses account for approximately two‐thirds of electrical losses.
342:
has the ability to remove sections of the wire insulation to improve connectivity; laser technology can provide unrivalled precision and repeatability to ensure precise connectivity.
603:
Pops, Horace, 1995, Physical
Metallurgy of Electrical Conductors, in Nonferrous Wire Handbook, Volume 3: Principles and Practice, The Wire Association International, pp. 7-22
382:
Breakdown voltage depends on the thickness of the covering, which can be of 3 types: Grade 1, Grade 2 and Grade 3. Higher grades have thicker insulation and thus higher
412:
If active cooling is provided by blowing air or circulating water, then much higher current densities can be achieved - proportionally to the effectiveness of cooling.
619:
Joseph, Günter, 1999, Copper: Its Trade, Manufacture, Use, and
Environmental Status, edited by Kundig, Konrad J.A., ASM International Vol. 2.03, Electrical Conductors
778:
338:. This means that electrical connections at the ends can be made without stripping off the insulation first, disadvantage however is that it can melt accidentally.
239:
Most often, magnet wire is composed of fully annealed, electrolytically refined copper to allow closer winding when making electromagnetic coils. High-purity
331:(Teflon) can be found. Older insulation materials include cotton, paper, or silk, but these are only useful for low-temperature applications up to 105°C.
323:
instead of copper are sometimes used. Various other insulators such as cotton (sometimes permeated with some kind of coagulating agent/thickener, such as
301:
Self-supporting coils are wound with wire coated with at least two layers, the outermost being a thermoplastic that bonds the turns together when heated.
564:
conductors. However, the use of larger-sized conductors results in the winding strength of aluminium being nearly equivalent to that of copper windings.
219:, electrolytically refined copper. Aluminium magnet wire is sometimes used for large transformers and motors. The insulation is typically made of tough
1074:
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470:
548:
Transformer windings are normally made from copper but aluminium is a suitable competitor where weight and first cost are decisive factors.
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grades are used for high-temperature applications in reducing atmospheres or in motors or generators cooled by hydrogen gas.
57:
409:
may affect the distribution of the current across the section by concentrating the current on the surface of the conductor.
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made of fused glass powder. Modern magnet wire typically uses one to four layers (in the case of quad-film type wire) of
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For ease of manufacturing, some low-temperature-grade magnet wire has insulation that can be removed by the heat of
316:, and polyester film are also widely used across the world for various applications like transformers and reactors.
79:
339:
46:
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Early developments in motor efficiency focused on reducing electrical losses by increasing the packing weight of
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The trend in modern generators is to operate at higher temperatures and higher electrical conductivities with
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film insulation, often of two different compositions, to provide a tough, continuous insulating layer.
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An aluminium wire must have 1.6 times the cross sectional area as a copper wire to achieve comparable
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and enamel. Lacquers permit the close spacing of windings to give best efficiency in the coils.
968:
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390:
271:
212:, electric guitar pickups, and other applications that require tight coils of insulated wire.
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696:
The emerging electrical markets for copper, Bloomsbury
Minerals Economics LTD, July 6, 2010
976:
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897:
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224:
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93:
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propulsion of large ships. The smallest motors move the hands in electric wristwatches.
255:
Although described as "enameled", enameled wire is not, in fact, coated with a layer of
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842:
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or millimeters) or area (square millimeters), temperature class, and insulation class.
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133:
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convert electrical energy into mechanical motion, usually through the interaction of
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Cross-sectional view of AWG33 magnet wire taken using a scanning electron microscope
949:
394:
279:
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506:
usually have 20% more copper in the stator winding than its standard counterpart.
736:"VTI : Aluminum vs. Copper: Conductors in Low Voltage Dry Type Transformers"
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for field bars and magnetic wire in place of formerly used deoxidized copper.
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to reduce load losses in continuous-use induction-type motors above 1
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indicates the temperature of the wire at which it has a 20,000 hour
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469:
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132:"Magnetic wire" redirects here. For magnetic wire recording, see
1191:
710:"Find out why we prefer to make cables and wires out of copper!"
533:
is used for certain high-frequency transformers to minimize the
313:
304:
Other types of insulation such as fiberglass yarn with varnish,
760:
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29:
422:. Due to this, copper magnet wires contribute to improving
363:
Like other wire, magnet wire is classified by diameter (
139:"Fly-wire (wire)" redirects here. For jumper wires, see
1154:
1108:
967:
795:
60:. Unsourced material may be challenged and removed.
474:Copper windings in a miniaturized electric motor
274:use (in order of increasing temperature range)
162:Inductor made with magnet wire wound around a
772:
8:
294:, polyamide-polyimide (or amide-imide), and
779:
765:
757:
677:"Electric Motors (for 14 to 16 year-olds)"
120:Learn how and when to remove this message
1075:Rotary variable differential transformer
1055:Linear variable differential transformer
738:. Vt-inc.com. 2006-08-29. Archived from
656:"Solderability of Enamelled Copper Wire"
593:
319:In the audio industry, wires made from
615:
613:
611:
609:
599:
597:
426:in equipment such as electric motors.
188:. It is used in the construction of
184:wire coated with a very thin layer of
458:coils, hard drive head positioners,
27:Coated wire for construction of coils
7:
828:Condition monitoring of transformers
730:
728:
726:
704:
702:
552:expressed in currency per kilowatt.
215:The wire itself is most often fully
58:adding citations to reliable sources
923:Toroidal inductors and transformers
635:. MWS Wire Industries. January 2024
434:Magnet wire is used in windings of
25:
958:
654:Yates, Alan (16 February 2009).
34:
572:is not necessary with copper.
45:needs additional citations for
1095:Variable-frequency transformer
945:Transformer utilization factor
630:"Magnet Wire Insulation Guide"
1:
227:, as the name might suggest.
1004:Energy efficient transformer
1009:Amorphous metal transformer
893:Resonant inductive coupling
833:Electrical insulation paper
223:film materials rather than
1239:
138:
131:
956:
489:Electric motors contain
153:Fly wire (disambiguation)
987:Distribution transformer
206:hard disk head actuators
143:. For wire bridges, see
1085:Solid-state transformer
992:Pad-mounted transformer
938:Transformer oil testing
355:across adjacent turns.
329:polytetrafluoroethylene
147:. For patch leads, see
1060:Parametric transformer
1026:Instrument transformer
982:Buck–boost transformer
933:Dissolved gas analysis
537:
475:
379:
166:
151:. For other uses, see
1223:Electric transformers
1043:Isolation transformer
1021:Grounding transformer
999:Delta-wye transformer
878:Pressure relief valve
528:
473:
462:, and other devices.
377:
161:
353:thermal conductivity
340:Laser wire stripping
54:improve this article
1172:Mitsubishi Electric
1090:Trigger transformer
1080:Scott-T transformer
1036:Voltage transformer
1031:Current transformer
1016:Flyback transformer
848:Induction regulator
1182:Schneider Electric
1100:Zigzag transformer
1070:Rotary transformer
1065:Planar transformer
1048:Austin transformer
903:Short-circuit test
883:Quadrature booster
853:Leakage inductance
582:oxygen-free copper
538:
476:
466:In electric motors
384:breakdown voltages
380:
241:oxygen-free copper
167:
1200:
1199:
868:Open-circuit test
424:energy efficiency
391:temperature class
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712:. Eurocopper.org
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272:insulating films
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898:Severity factor
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69:"Magnet wire"
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65:Find sources:
59:
55:
49:
48:
43:This article
41:
37:
32:
31:
19:
18:Enameled wire
950:Vector group
857:
744:. Retrieved
740:the original
714:. Retrieved
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681:. Retrieved
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659:. Retrieved
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637:. Retrieved
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440:transformers
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430:Applications
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395:service life
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290:, polyester-
280:polyurethane
270:Magnet wire
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257:enamel paint
254:
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231:Construction
214:
190:transformers
173:
169:
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116:
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90:
83:
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64:
52:Please help
47:verification
44:
1116:Hybrid coil
918:Tap changer
858:Magnet wire
788:Transformer
542:transformer
535:skin effect
456:loudspeaker
407:skin effect
310:kraft paper
278:(Formvar),
170:Magnet wire
149:patch cable
110:August 2014
1207:Categories
1141:Tesla coil
1126:Oudin coil
818:Center tap
746:2013-06-01
716:2013-06-01
683:2013-06-01
588:References
500:horsepower
452:headphones
448:generators
420:resistance
365:AWG number
251:Insulation
186:insulation
80:newspapers
570:oxidation
531:Litz wire
444:inductors
336:soldering
296:polyimide
292:polyimide
288:polyester
284:polyamide
194:inductors
182:aluminium
141:jump wire
1177:ProlecGE
888:Resolver
873:Polarity
863:Metadyne
217:annealed
202:speakers
1187:Siemens
913:Synchro
838:Growler
813:Bushing
661:21 June
639:24 July
558:lacquer
325:beeswax
308:paper,
265:polymer
221:polymer
94:scholar
796:Topics
790:topics
511:stator
327:) and
321:silver
306:aramid
198:motors
178:copper
145:jumper
96:
89:
82:
75:
67:
1109:Coils
969:Types
803:Balun
633:(PDF)
491:coils
176:is a
101:JSTOR
87:books
1213:Wire
1192:TBEA
663:2014
641:2024
389:The
351:and
314:mica
259:or
73:news
1162:ABB
369:SWG
180:or
172:or
56:by
1209::
725:^
701:^
608:^
596:^
540:A
454:,
450:,
446:,
442:,
438:,
417:DC
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117:(
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108:(
98:·
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