{"id":817,"date":"2026-08-27T05:05:52","date_gmt":"2026-08-27T05:05:52","guid":{"rendered":"https:\/\/demos2us.in\/electric\/?post_type=product&#038;p=817"},"modified":"2026-09-01T05:34:32","modified_gmt":"2026-09-01T05:34:32","slug":"motor-starting-auto-transformers","status":"publish","type":"product","link":"https:\/\/demos2us.in\/electric\/products\/motor-starting-auto-transformers\/","title":{"rendered":"Motor Starting Auto-Transformers"},"content":{"rendered":"<p style=\"font-weight: 400;\"><strong>Motor Starting Auto-Transformers\u00a0<\/strong>(MSA) serve to mitigate inrush current by decreasing the applied voltage during the start-up phase of both induction and synchronous motors.<\/p>\n<p style=\"font-weight: 400;\">Direct-online starting of a motor usually generates voltage flicker and mechanical stress to the equipment. To circumvent these issues, starting the motor at a reduced voltage is necessary a task accomplished through the use of an auto-transformer.<\/p>\n<p style=\"font-weight: 400;\"><strong>Auto-transformer\u00a0<\/strong>significantly reduce the high starting current while providing moderate starting torque. They typically feature voltage taps set at 50%, 65% and 80% of the rated voltage. Unlike reactor-based motor starters where motor voltage remains fixed,\u00a0<strong>autotransformers<\/strong>\u00a0allow for further reduction in starting current while maintaining the same starting torque.<\/p>\n<p style=\"font-weight: 400;\">During the startup phase the motor is connected to the taps of the\u00a0<strong>auto-transformers<\/strong>, resulting in lower starting voltage and consequently lower current draw, yielding less torque compared to connection to the line voltage.<\/p>\n<p style=\"font-weight: 400;\">Starting Characteristics<\/p>\n<p style=\"font-weight: 400;\">\u00a0 \u00a0 l\u00a0\u00a0Motor terminal voltage is less than line voltage (by transformer ratio)<\/p>\n<p style=\"font-weight: 400;\">\u00a0 \u00a0 l\u00a0\u00a0Motor current exceeds line current (by inverse of transformer ratio)<\/p>\n<p style=\"font-weight: 400;\">\u00a0 \u00a0 l\u00a0\u00a0Starting torque is reduced by the square of the motor terminal voltage<\/p>\n<p style=\"font-weight: 400;\">\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0\u00a0 \u00a0 \u00a0 *Consult factory for higher values.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.electricvalley.net\/img\/Motor%20Starting%20_detail_2.jpg\" alt=\"Motor Starting Auto-Transformers\u00a0\u00a0\" \/><\/p>\n","protected":false},"featured_media":818,"template":"","product_category":[7,10],"class_list":["post-817","product","type-product","status-publish","has-post-thumbnail","hentry","product_category-power-resistors","product_category-motor-starting"],"acf":[],"_links":{"self":[{"href":"https:\/\/demos2us.in\/electric\/wp-json\/wp\/v2\/product\/817","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/demos2us.in\/electric\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/demos2us.in\/electric\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/demos2us.in\/electric\/wp-json\/wp\/v2\/media\/818"}],"wp:attachment":[{"href":"https:\/\/demos2us.in\/electric\/wp-json\/wp\/v2\/media?parent=817"}],"wp:term":[{"taxonomy":"product_category","embeddable":true,"href":"https:\/\/demos2us.in\/electric\/wp-json\/wp\/v2\/product_category?post=817"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}