{"id":278,"date":"2026-08-22T02:34:14","date_gmt":"2026-08-21T18:34:14","guid":{"rendered":"https:\/\/q8bbzjnpm5.wpdns.site\/?p=278"},"modified":"2026-08-29T23:43:38","modified_gmt":"2026-08-29T15:43:38","slug":"boosted-by-99-9-pure-copper-subian-power-transformers-excel","status":"publish","type":"post","link":"https:\/\/subian-electric.com\/fr\/news\/boosted-by-99-9-pure-copper-subian-power-transformers-excel\/","title":{"rendered":"Propuls\u00e9 par 99.9% Cuivre Pur ! Les Transformateurs de Puissance Subian Excellent"},"content":{"rendered":"<p>Une usine sid\u00e9rurgique vietnamienne a command\u00e9 quatre transformateurs \u00e0 Jiangsu Subian Electric Power, 4 MVA et 22\/0,4 kV, et le directeur des achats a pos\u00e9 une question l\u00e9gitime \u00e0 l'ing\u00e9nieur commercial : \u201c Votre prix est 25 % inf\u00e9rieur aux prix europ\u00e9ens \u2014 comment puis-je \u00eatre s\u00fbr que les enroulements ne sont pas en aluminium recouvert de cuivre ? \u201d L'ing\u00e9nieur commercial a fourni un rapport d'essai d'usine indiquant que les mesures de r\u00e9sistance des enroulements sont presque identiques \u00e0 la r\u00e9sistivit\u00e9 du cuivre (\u00e9cart de 0,5%), preuve de cuivre \u00e9lectrolytique authentique avec une puret\u00e9 de 99,99% et une invitation \u00e0 voir le processus d'enroulement en action. Le directeur a accept\u00e9 de se rendre \u00e0 l'usine et de regarder le processus d'enroulement en cours. L'utilisation de cuivre \u00e0 99,9% dans les enroulements de transformateur est un petit d\u00e9tail qui fait une grande diff\u00e9rence.<\/p>\n<p>Cet article explique l'importance de la puret\u00e9 du cuivre dans les transformateurs en ce qui concerne les pertes, la temp\u00e9rature, la capacit\u00e9 de surcharge et la dur\u00e9e de vie op\u00e9rationnelle, comment v\u00e9rifier la puret\u00e9 du cuivre et combien cela co\u00fbte. Vous d\u00e9couvrirez \u00e9galement comment Jiangsu Subian Electric Power utilise les transformateurs en cuivre \u00e0 99,9% dans ses produits.<\/p>\n<blockquote><p>En r\u00e9sum\u00e9 : La qualit\u00e9 de l'enroulement en cuivre est \u00e9valu\u00e9e en fonction de sa conductivit\u00e9 : le cuivre \u00e9lectrolytique pur \u00e0 99,9% (ETP) est caract\u00e9ris\u00e9 par une r\u00e9sistivit\u00e9 d'environ 0,0172 \u03a9\u00b7mm\u00b2\/m \u00e0 20 \u00b0C, et un niveau de conductivit\u00e9 de 100\u2013101% IACS tandis que l'aluminium est \u00e0 0,0282 \u03a9\u00b7mm\u00b2\/m et environ 61% IACS \u2014 c'est pourquoi le cuivre est capable de conduire le courant avec environ 40% de perte en moins tout en maintenant la m\u00eame section transversale. Compar\u00e9 \u00e0 un transformateur en aluminium, qui est class\u00e9 de mani\u00e8re similaire, le transformateur en cuivre a un r\u00e9gime de fonctionnement plus frais, une perte de charge inf\u00e9rieure de 20\u201330% et une capacit\u00e9 de surcharge plus \u00e9lev\u00e9e m\u00eame avec le m\u00eame syst\u00e8me d'isolation. La r\u00e9sistance de l'enroulement en cuivre peut \u00eatre v\u00e9rifi\u00e9e par rapport \u00e0 la norme de r\u00e9sistivit\u00e9 du cuivre \u00e0 l'aide d'un micro-ohmm\u00e8tre ; la variation de la r\u00e9sistance des enroulements entre les phases ne doit pas d\u00e9passer 2%.<\/p><\/blockquote>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-279\" src=\"https:\/\/subian-electric.com\/wp-content\/uploads\/2026\/08\/Boosted-By-99-9-Pure-Copper-Subian-Power-Transformers-Excel.webp\" alt=\"Boosted By 99 9 Pure Copper Subian Power Transformers Excel\" width=\"1448\" height=\"1086\" \/><\/p>\n<hr \/>\n<h2 id=\"why-copper\">Pourquoi la puret\u00e9 du cuivre est-elle importante dans les enroulements de transformateur<\/h2>\n<p>Les enroulements du transformateur sont les composants qui transportent le courant. Leur r\u00e9sistance d\u00e9termine la quantit\u00e9 de perte d'\u00e9nergie due \u00e0 la chaleur et d\u00e9finit ainsi environ 50\u201370% des pertes globales \u00e0 pleine charge. La r\u00e9sistance de l'enroulement est en relation lin\u00e9aire avec la r\u00e9sistivit\u00e9 et la puret\u00e9 du conducteur. \u00c9tant donn\u00e9 que la quantit\u00e9 d'impuret\u00e9s dans le cuivre, telles que l'oxyg\u00e8ne, le phosphore, l'argent et d'autres \u00e9l\u00e9ments traces, augmente la r\u00e9sistivit\u00e9 au-dessus des valeurs du cuivre pur (0,0172 \u03a9\u00b7mm\u00b2\/m \u00e0 20 \u00b0C), on peut dire qu'un enroulement \u201c en cuivre \u201d peut \u00eatre produit \u00e0 partir de cuivre recycl\u00e9 ou de cuivre de faible puret\u00e9, ce qui augmente la r\u00e9sistivit\u00e9 de 2 \u00e0 5% et entra\u00eene une augmentation des pertes de charge, de la temp\u00e9rature et du vieillissement de l'isolation.<\/p>\n<p>En cons\u00e9quence, plus de r\u00e9sistance entra\u00eene plus de chaleur, ce qui signifie une temp\u00e9rature de point chaud plus \u00e9lev\u00e9e, augmentant le vieillissement de l'isolation. En essence, un enroulement avec une r\u00e9sistivit\u00e9 augment\u00e9e de 4% peut fonctionner \u00e0 3\u20136 \u00b0C plus chaud sous pleine charge, perdant d\u00e9j\u00e0 10\u201320% de dur\u00e9e de vie de l'isolation pendant un cycle de vie de 30 ans.<\/p>\n<h2 id=\"copper-vs-aluminum\">Enroulements en cuivre vs. aluminium : une comparaison honn\u00eate<\/h2>\n<table>\n<thead>\n<tr>\n<th>Propri\u00e9t\u00e9<\/th>\n<th>Cuivre (99.9% ETP)<\/th>\n<th>Aluminium<\/th>\n<th>Impact<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>R\u00e9sistivit\u00e9 @ 20 \u00b0C<\/td>\n<td>0172 \u03a9\u00b7mm\u00b2\/m<\/td>\n<td>0282 \u03a9\u00b7mm\u00b2\/m<\/td>\n<td>Cuivre ~40% inf\u00e9rieur<\/td>\n<\/tr>\n<tr>\n<td>Conductivit\u00e9<\/td>\n<td>100\u2013101% IACS<\/td>\n<td>~61% IACS<\/td>\n<td>Le cuivre transporte plus de courant par surface<\/td>\n<\/tr>\n<tr>\n<td>Volume relatif du conducteur pour la m\u00eame perte<\/td>\n<td>1.0<\/td>\n<td>~1.6<\/td>\n<td>L'aluminium n\u00e9cessite des enroulements plus grands<\/td>\n<\/tr>\n<tr>\n<td>Poids de l'enroulement (m\u00eame puissance)<\/td>\n<td>~2\u00d7 plus lourd que l'aluminium<\/td>\n<td>Plus l\u00e9ger<\/td>\n<td>Conception de transport et de support<\/td>\n<\/tr>\n<tr>\n<td>Conductivit\u00e9 thermique<\/td>\n<td>~400 W\/(m\u00b7K)<\/td>\n<td>~230 W\/(m\u00b7K)<\/td>\n<td>Le cuivre conduit la chaleur plus rapidement<\/td>\n<\/tr>\n<tr>\n<td>Perte de charge (m\u00eame puissance)<\/td>\n<td>R\u00e9f\u00e9rence<\/td>\n<td>~20\u201330% plus \u00e9lev\u00e9e<\/td>\n<td>Co\u00fbt d'exploitation plus \u00e9lev\u00e9<\/td>\n<\/tr>\n<tr>\n<td>Co\u00fbt<\/td>\n<td>Baseline (prix des m\u00e9taux plus \u00e9lev\u00e9)<\/td>\n<td>~10\u201320% moins cher au total<\/td>\n<td>Diff\u00e9rence de co\u00fbt initial<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-280\" src=\"https:\/\/subian-electric.com\/wp-content\/uploads\/2026\/08\/Copper-vs.-Aluminum-Windings-An-Honest-Comparison.webp\" alt=\"Copper vs. Aluminum Windings An Honest Comparison\" width=\"1448\" height=\"1086\" \/><\/p>\n<p>Bien qu'il soit vrai que les enroulements en aluminium ne soient pas exactement fiables, un bon transformateur en aluminium ayant des conducteurs suffisamment grands et de bonnes joints (le point faible est li\u00e9 aux joints en aluminium fusionn\u00e9s) peut bien fonctionner. Mais si nous regardons le probl\u00e8me honn\u00eatement, le cuivre est meilleur en ce qui concerne les pertes, la performance thermique, la fiabilit\u00e9 des connexions et la capacit\u00e9 de surcharge, tandis que les co\u00fbts initiaux sont environ 10 \u00e0 20% plus \u00e9lev\u00e9s. Le choix d\u00e9pend de l'application : le cuivre est meilleur pour les industries \u00e0 forte charge avec de longs temps de fonctionnement et des surcharges fr\u00e9quentes, tandis que l'aluminium peut \u00eatre une option pour des installations \u00e9conomiques l\u00e9g\u00e8res.<\/p>\n<h2 id=\"specifications\">Grades et sp\u00e9cifications du cuivre<\/h2>\n<table>\n<thead>\n<tr>\n<th>Grade<\/th>\n<th>Puret\u00e9<\/th>\n<th>Conductivit\u00e9<\/th>\n<th>Utilisation typique dans les transformateurs<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Cuivre ETP (cuivre \u00e9lectrolytique \u00e0 pitch dur)<\/td>\n<td>\u2265 99.9%<\/td>\n<td>100\u2013101% IACS<\/td>\n<td>Enroulements de haute qualit\u00e9 standard<\/td>\n<\/tr>\n<tr>\n<td>Cuivre sans oxyg\u00e8ne (OFC)<\/td>\n<td>\u2265 99.95%<\/td>\n<td>101\u2013102% IACS<\/td>\n<td>Enroulements premium \/ sp\u00e9ciaux<\/td>\n<\/tr>\n<tr>\n<td>Cuivre \u00e0 faible teneur en oxyg\u00e8ne<\/td>\n<td>\u2265 99.9%<\/td>\n<td>~100% IACS<\/td>\n<td>Conducteurs de transformateur en coul\u00e9e continue<\/td>\n<\/tr>\n<tr>\n<td>Cuivre recycl\u00e9 \/ de qualit\u00e9 inf\u00e9rieure<\/td>\n<td>&lt; 99,5%<\/td>\n<td>97\u201399% IACS<\/td>\n<td>Enroulements bon march\u00e9 \u2014 \u00e0 \u00e9viter pour un service critique<\/td>\n<\/tr>\n<tr>\n<td>Cuivre \u00e9maill\u00e9 \/ isol\u00e9 (fil)<\/td>\n<td>C\u0153ur \u2265 99.9%<\/td>\n<td>100\u2013101% IACS<\/td>\n<td>Distribution et petits enroulements<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Le cuivre ETP ou \u00e0 faible teneur en oxyg\u00e8ne avec une puret\u00e9 de 99.9% et une conductivit\u00e9 \u00e9gale ou sup\u00e9rieure \u00e0 100% IACS sont les sp\u00e9cifications g\u00e9n\u00e9ralement utilis\u00e9es pour les transformateurs utilis\u00e9s dans l'\u00e9nergie et la distribution. Vous devriez demander le grade et la puret\u00e9 du cuivre si vous remarquez les termes \u201c cuivre pur \u201d dans les sp\u00e9cifications, car \u201c cuivre \u201d seul n'est pas fiable. Les bons fabricants sp\u00e9cifieront le grade du cuivre, vous fourniront un certificat de mat\u00e9riau et offriront les lectures de r\u00e9sistance des enroulements qui correspondent aux valeurs de r\u00e9sistivit\u00e9 du cuivre.<\/p>\n<h2 id=\"verification\">Comment v\u00e9rifier le cuivre 99.9% dans un transformateur<\/h2>\n<p>Il n'est pas n\u00e9cessaire de se fier \u00e0 la brochure, car la qualit\u00e9 du cuivre peut \u00eatre v\u00e9rifi\u00e9e par trois approches diff\u00e9rentes. Documentation : le fabricant doit fournir un certificat de mat\u00e9riau (certificat d'essai de fabrication) qui indique la puret\u00e9 et la conductivit\u00e9 du conducteur en cuivre, ainsi qu'une fiche de conception contenant le grade du cuivre, la section transversale du conducteur et le nombre de tours. Test de r\u00e9sistance des enroulements : une fois l'assemblage termin\u00e9, la r\u00e9sistance des enroulements de chaque phase doit \u00eatre quantifi\u00e9e \u00e0 l'aide d'un micro-ohmm\u00e8tre et compar\u00e9e \u00e0 la valeur attendue obtenue \u00e0 partir des donn\u00e9es sur la longueur du conducteur, la section transversale et la r\u00e9sistivit\u00e9 du cuivre (0.0172 \u03a9\u00b7mm\u00b2\/m \u00e0 20 \u00b0C). Si la valeur r\u00e9elle s'\u00e9carte de plus de 2-3% de la valeur th\u00e9orique, on peut suspecter que le m\u00e9tal utilis\u00e9 est de qualit\u00e9 inf\u00e9rieure ou que les joints sont mal r\u00e9alis\u00e9s. Toute installation suit ce type d'inspection dans le cadre de la norme IEC 60076-1. T\u00e9moignage en usine : il est important d'observer le processus d'enroulement - on doit voir du fil de cuivre sans oxyg\u00e8ne produit et enroul\u00e9 de mani\u00e8re appropri\u00e9e. Il faut \u00e9galement v\u00e9rifier la qualit\u00e9 des joints ; tandis que les joints soud\u00e9s sont les maillons faibles dans les conducteurs en aluminium, la situation est diff\u00e9rente dans le cas des conducteurs en cuivre o\u00f9 la qualit\u00e9 inf\u00e9rieure des joints bras\u00e9s ou boulonn\u00e9s entra\u00eene des r\u00e9sultats d\u00e9favorables par la suite.<\/p>\n<p>L'un des principaux tests est la diff\u00e9rence de r\u00e9sistance des enroulements repr\u00e9sentant un d\u00e9s\u00e9quilibre entre les phases - la valeur optimale doit \u00eatre inf\u00e9rieure \u00e0 2%. Un d\u00e9s\u00e9quilibre d'enroulement plus \u00e9lev\u00e9 signifie que la qualit\u00e9 du conducteur est diff\u00e9rente, que le nombre de tours est diff\u00e9rent ou que la qualit\u00e9 de construction est en question. Pour tout fabricant, y compris Jiangsu Subian Electric Power, il ne devrait pas \u00eatre difficile de fournir les documents appropri\u00e9s ; les preuves devraient \u00eatre \u00e0 port\u00e9e de main.<\/p>\n<table>\n<thead>\n<tr>\n<th>Niveau de v\u00e9rification<\/th>\n<th>M\u00e9thode<\/th>\n<th>Ce que cela prouve<\/th>\n<th>Co\u00fbt<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Documentation<\/td>\n<td>Certificat d'essai de fabrication pour le conducteur<\/td>\n<td>Grade, puret\u00e9, conductivit\u00e9 revendiqu\u00e9s<\/td>\n<td>Inclus<\/td>\n<\/tr>\n<tr>\n<td>R\u00e9sistance des enroulements (usine)<\/td>\n<td>Micro-ohmm\u00e8tre selon IEC 60076-1<\/td>\n<td>R\u00e9sistivit\u00e9 du conducteur, \u00e9quilibre de phase \u2264 2%<\/td>\n<td>Inclus dans la batterie de tests<\/td>\n<\/tr>\n<tr>\n<td>Test de perte de charge<\/td>\n<td>Mesure IEC 60076-1<\/td>\n<td>Niveau de perte coh\u00e9rent avec les enroulements en cuivre<\/td>\n<td>Inclus dans la batterie de tests<\/td>\n<\/tr>\n<tr>\n<td>Test tiers \/ t\u00e9moin<\/td>\n<td>T\u00e9moin acheteur ou laboratoire<\/td>\n<td>Confirmation ind\u00e9pendante<\/td>\n<td>$2 000\u2013$15 000<\/td>\n<\/tr>\n<tr>\n<td>Visite d'usine<\/td>\n<td>Inspection de la ligne d'enroulement<\/td>\n<td>Barre de cuivre coul\u00e9 continu, tension contr\u00f4l\u00e9e<\/td>\n<td>Co\u00fbt de transport<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2 id=\"impact\">L'impact sur la performance : Pertes, Temp\u00e9rature et Surcharge<\/h2>\n<table>\n<thead>\n<tr>\n<th>Attribut de performance<\/th>\n<th>Unit\u00e9 \u00e0 enroulement en cuivre<\/th>\n<th>Unit\u00e9 en aluminium \u00e9quivalente<\/th>\n<th>Cons\u00e9quence pratique<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Perte de charge \u00e0 la charge nominale<\/td>\n<td>R\u00e9f\u00e9rence<\/td>\n<td>~20\u201330% plus \u00e9lev\u00e9e<\/td>\n<td>Co\u00fbt \u00e9nerg\u00e9tique annuel plus \u00e9lev\u00e9<\/td>\n<\/tr>\n<tr>\n<td>Temp\u00e9rature du point le plus chaud de l'enroulement \u00e0 pleine charge<\/td>\n<td>R\u00e9f\u00e9rence<\/td>\n<td>~3\u201310 \u00b0C plus \u00e9lev\u00e9<\/td>\n<td>Vieillissement de l'isolation plus rapide<\/td>\n<\/tr>\n<tr>\n<td>Consommation de la dur\u00e9e de vie de l'isolation<\/td>\n<td>R\u00e9f\u00e9rence<\/td>\n<td>~10\u201330% de plus par an \u00e0 facteur de charge \u00e9lev\u00e9<\/td>\n<td>Dur\u00e9e de vie de service plus courte<\/td>\n<\/tr>\n<tr>\n<td>Capacit\u00e9 de surcharge \u00e0 la m\u00eame limite de temp\u00e9rature<\/td>\n<td>Plus \u00e9lev\u00e9<\/td>\n<td>Plus bas<\/td>\n<td>Plus de r\u00e9serve utilisable pour les pics<\/td>\n<\/tr>\n<tr>\n<td>R\u00e9cup\u00e9ration de surcharge d'urgence<\/td>\n<td>Faster cool-down<\/td>\n<td>Slower<\/td>\n<td>Better thermal time constant<\/td>\n<\/tr>\n<tr>\n<td>Connection reliability<\/td>\n<td>Brazed\/bolted, forgiving<\/td>\n<td>Welded joints need care<\/td>\n<td>Fewer joint failures<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>These differences are most significant at high load factors. A facility utilizing its transformer at between 80-100% capacity continuously will be able to get back the copper premium with lower losses in energy over a period of typically 2-6 years whereas a transformer in a rural area with light load will never retrieve the premium in terms of energy although it helps in gaining reliability and ensuring better connection integrity. Therefore, this is the reason for why the copper versus aluminum debate depending on usage, and the answer to which should be recommended based on the load duration curve than on marketing.<\/p>\n<h2 id=\"subian\">Subian&#8217;s Approach: 99.9% Copper Across the Range<\/h2>\n<p>Jiangsu Subian Electric Power produces its distribution and power transformers from 10 kVA to 100 MVA according to IEC 60076 using 99.9% electrolytic copper windings by default, not as an upgrade. The need for high-quality copper by the company&#8217;s export customers in the industrial and infrastructure projects is due to the operation of their equipment at significant load factors and the resulting advantages of using copper in terms of lower losses and better thermal performance that allow to recuperate expenses incurred on copper in the course of several years and have limited metal replacement cost. The windings are made from a low-oxygen copper wire produced in the factory, carried out on servo-controlled devices maintaining tension of conductors within a \u00b13% range, equipped with a system guaranteeing proper placement of insulation between the layers.<\/p>\n<p>Subian guarantees the quality of copper by providing documents on the composition of the conductors used in winding machines, measurements of winding resistance for each winding, and passing factory tests defined by standard IEC 60076-1 including the total value of copper losses. Factory employees invite customers to see the production line \u2014 this approach was used by Subian to convince the customer from Vietnam.<\/p>\n<h2 id=\"brands-pricing\">Brand Comparison &amp; Price Ranges<\/h2>\n<table>\n<thead>\n<tr>\n<th>Marque<\/th>\n<th>Winding Policy<\/th>\n<th>Typical Price (2,000 kVA, copper, IEC-compliant)<\/th>\n<th>Remarques<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Hitachi Energy<\/td>\n<td>Copper standard on most power transformers<\/td>\n<td>$35,000\u2013$70,000<\/td>\n<td>Premium engineering, global service<\/td>\n<\/tr>\n<tr>\n<td>Siemens Energy<\/td>\n<td>Copper standard on power transformers<\/td>\n<td>$38,000\u2013$75,000<\/td>\n<td>Digital ecosystems, top-spec options<\/td>\n<\/tr>\n<tr>\n<td>Schneider Electric<\/td>\n<td>Copper or aluminum by design<\/td>\n<td>$25,000\u2013$55,000<\/td>\n<td>Distribution focus<\/td>\n<\/tr>\n<tr>\n<td>TBEA<\/td>\n<td>Copper standard on power range<\/td>\n<td>$20 000\u2013$45 000<\/td>\n<td>Large-unit specialist<\/td>\n<\/tr>\n<tr>\n<td>Jiangsu Subian Electric Power<\/td>\n<td>99.9% copper standard across range<\/td>\n<td>$18 000\u2013$38 000<\/td>\n<td>Documented copper purity at competitive price<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Prices differ with specification, efficiency class, and region; these can be taken for planning purposes. Global brands like Hitachi Energy, Siemens Energy, and Schneider Electric use copper in their power transformer lines, pricing accordingly with premiums based on their international services and technical capabilities. Chinese firms like Jiangsu Subian Electric Power use the same 99.9% electrolytic copper and IEC 60076 testing methods, and in addition have now comparable levels of automation, but with prices of about 20-40% lower than those offered by European brands. For the buyer, it is not an issue of brand preference, but an issue of verification: the supplier must produce the material certificate and winding resistance information for the exact unit sold.<\/p>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-281\" src=\"https:\/\/subian-electric.com\/wp-content\/uploads\/2026\/08\/How-to-Choose-a-Copper-Wound-Transformer-7-Checks.webp\" alt=\"How to Choose a Copper-Wound Transformer 7 Checks\" width=\"1448\" height=\"1086\" \/><\/p>\n<h2 id=\"how-to-choose\">How to Choose a Copper-Wound Transformer: 7 Checks<\/h2>\n<ul>\n<li>Go through the specification and confirm the conductor type, for example, check for 99.9 ETP copper, and ensure the specification states the conductivity (\u2265 100% IACS), and is more than merely &#8220;copper&#8221;.<\/li>\n<li>Ask for the manufacturer to provide you the conductor material certificate which is the mill test certificate confirming purity and conductivity of the conductor<\/li>\n<li>Confirm the winding resistance. Compare measured data with theoretical copper resistivity; the difference should be 2-3%. Check for phase unbalance, which should be less than 2%.<\/li>\n<li>Make a comparison with the aluminum alternative. The data of the load loss from the IEC 60076-1 test report should tell which material has been used as aluminum coils cannot be equated with copper loss levels.<\/li>\n<li>Check your load profile. In case of high load factor or long service life expect copper, instances of overload duty favoring copper; meanwhile, low duty applications may use aluminum<\/li>\n<li>Inspect joints. Field inspection \/ factory witnessing of winding connections; i.e. brazed copper connections are more forgiving in comparison to welded aluminum, which is notorious for failures.<\/li>\n<li>Witness the tests. A visit to the factory for viewing the winding shop and testing site represents the last proof of the status; any reputable supplier, including Jiangsu Subian Electric Power should be happy to welcome such visits.<\/li>\n<\/ul>\n<h2 id=\"faq\">Questions Fr\u00e9quemment Pos\u00e9es<\/h2>\n<h3>Why is 99.9% purity important for transformer copper?<\/h3>\n<p>The relationship of purity with resistivity is direct and resistivity has a direct connection with load loss. The resistivity of pure electrolytic copper is around 0.0172 \u03a9\u00b7mm\u00b2\/m at 20 \u00b0C with conductivity of 100\u2013101% IACS; even small impurities increase resistivity and lead to I\u00b2R loss heating. Winding with 3% resistivity operates at higher temperature during full load \u2013 around 3\u20136 \u00b0C higher at hottest spots, with insulation life being reduced by 10\u201320% during 30 years of operation because of insulation aging at the temperature above 98 \u00b0C whereby insulation life doubles every 6 \u00b0C.<\/p>\n<h3>How much more does a copper-wound transformer cost?<\/h3>\n<p>Typically, the copper coils increase the material expenses of a transformer by 10-20% as compared to the aluminum coils. In absolute terms, an IEC-compliant copper transformer with a power output of 2,000 kVA costs between $18,000 and $38,000 depending on the efficiency class and the specifications, while the equivalent aluminum one will cost approximately 10-20% less. However, the higher cost of copper is compensated for by energy savings within 2-6 years of operation at normal industrial load conditions, and lower hotspot temperature and the better overload capacity during the rest of the lifetime of the transformer.<\/p>\n<h3>How can I tell if a transformer really has copper windings?<\/h3>\n<p>There are three major methods that can be used. To begin with, a user should reference the winding resistance from the factory testing report: some known temperature is used, and according to the definition of copper resistance, its value will equal 0.0172 ohm\u00b7mm2\/m times the length of the cross-section. If the obtained results are compatible with this value, with the only exception allowed being a deviation of 2-3%, this indicates that the metal is indeed copper; an aluminum specimen would yield results higher by 60%. In the second method, the measured values of the load losses are compared to the specified ones: the amount of load losses for copper coils will be at copper value; for aluminum coils it will be lower. Finally, a user can require the material certificate, and in case of large purchases can observe the production process. Any trusted manufacturer, including Jiangsu Subian Electric Power, will be able to offer all the three options.<\/p>\n<h3>Are aluminum-wound transformers always worse?<\/h3>\n<p>No. A good aluminum transformer, with conductors of the right size and quality welding, will be just fine, particularly for light-loaded distribution applications needing the lowest possible price. Aluminum&#8217;s disadvantages \u2014 about 20\u201330% more losses due to the load, higher operating temperature, and the need for careful welding of joints \u2014 are more important in applications with a high load factor, where overloads occur often or long life is expected. The rule of thumb thus is: use copper for heavy continuous duty or for positions where overload is likely, while aluminum is acceptable with light duty or where price is of crucial importance.<\/p>\n<h3>What does Jiangsu Subian Electric Power include with a copper-wound transformer?<\/h3>\n<p>For each unit, Subian provides the following documents: a certificate of conductor materials that confirms 99.9% ETP\/low-oxygen copper purity and conductivity, a complete IEC 60076-1 test report conducted in the factory that includes measurements of winding resistance (in all phases and with no greater than 2% imbalance), and the measured values of no-load losses and load losses along with an exhaustive set of digital as-built documentation. The company supplies its 10 kVA &#8211; 100 MVA range with copper windings, which the customers can evaluate by themselves: the process of winding and testing can be observed on-site.<\/p>\n<h2 id=\"references\">R\u00e9f\u00e9rences<\/h2>\n<ul>\n<li><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/639\" rel=\"nofollow noopener\" target=\"_blank\">IEC 60076-1: Power transformers \u2013 Part 1: General<\/a> \u2014 the standard defining winding resistance testing, loss measurement, and load loss guarantees.<\/li>\n<li><a href=\"https:\/\/www.copper.org\/\" rel=\"nofollow noopener\" target=\"_blank\">Copper Development Association<\/a> \u2014 authoritative data on copper conductivity, resistivity, and grades (ETP, OFC, low-oxygen).<\/li>\n<li><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/26917\" rel=\"nofollow noopener\" target=\"_blank\">IEC 60076-20: Power transformers \u2013 Part 20: Energy efficiency<\/a> \u2014 efficiency classes that make low-loss copper windings economically decisive.<\/li>\n<li><a href=\"https:\/\/standards.ieee.org\/ieee\/57.104\/10935\/\" rel=\"nofollow noopener\" target=\"_blank\">IEEE C57.104: DGA interpretation<\/a> \u2014 background on how hot operation from high-resistance windings appears in gas analysis.<\/li>\n<li><a href=\"https:\/\/www.hitachienergy.com\/\" rel=\"nofollow noopener\" target=\"_blank\">Hitachi Energy<\/a> \u2014 reference on premium copper-wound power transformer engineering.<\/li>\n<li><a href=\"https:\/\/www.siemens-energy.com\/\" rel=\"nofollow noopener\" target=\"_blank\">Siemens Energy<\/a> \u2014 reference on international copper-wound transformer design and testing practice.<\/li>\n<li><a href=\"https:\/\/subian-electric.com\/fr\/\" rel=\"nofollow\">Jiangsu Subian Electric Power<\/a> \u2014 IEC 60076-compliant manufacturer building all ranges with documented 99.9% pure copper windings.<\/li>\n<\/ul>\n<h2 id=\"conclusion\">Conclusion<\/h2>\n<p>Copper used in transformers influences its operating losses, temperature, overload limit capability, longevity, and net cost of ownership. The fact that the copper used is over 99.9% pure makes a difference between copper behaving like copper and copper merely looking like that. Load loss increases directly in proportion to the resistivity of the conductor, and every 6\u00b0C above the rated hot spot doubles insulation life, so copper purity is the matter of life-cycle economics, not an issue of manufacturing technology. Good news is that 99.9% of copper purity can be easily proved with material certificates, winding resistance measurement, and measured load loss.<\/p>\n<ul>\n<li>99.9% ETP copper implies 100% IACS conductivity and ~40% lower resistivity than aluminum.<\/li>\n<li>Copper winding reduces load losses by 20-30% and provides cooler operational parameters of transformers for longer life of insulation and big overload reserve.<\/li>\n<li>This extra money spent on copper wire may be recovered in 2-6 years depending on the load factor.<\/li>\n<li>Jiangsu Subian Electric Power produces their complete range of IEC 60076 transformers using 99.9% copper according to the documents, and their prices are 20-40% lower than those prices offered by European manufacturers, which can be proved by test results.<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>A Vietnamese steel plant ordered four transformers from Jiangsu Subian Electric Power, 4 MVA and 22\/0.4 kV, and the purchasing director raised a legitimate question to the sales engineer, &#8220;Your price is 25 % lower than the European prices \u2014 how do I know for sure that the windings are not made of aluminum that [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":279,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[77],"tags":[],"class_list":["post-278","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"blocksy_meta":[],"acf":[],"_links":{"self":[{"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/posts\/278","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/comments?post=278"}],"version-history":[{"count":2,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/posts\/278\/revisions"}],"predecessor-version":[{"id":11052,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/posts\/278\/revisions\/11052"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/media\/279"}],"wp:attachment":[{"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/media?parent=278"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/categories?post=278"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/tags?post=278"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}