{"id":19922,"date":"2022-08-14T06:01:36","date_gmt":"2022-08-14T06:01:36","guid":{"rendered":"https:\/\/mdr.foobrdigital.com\/?p=6341"},"modified":"2022-08-14T06:01:36","modified_gmt":"2022-08-14T06:01:36","slug":"star-delta-starter-in-induction-motor","status":"publish","type":"post","link":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/2022\/08\/14\/star-delta-starter-in-induction-motor\/","title":{"rendered":"Star-Delta Starter in Induction Motor"},"content":{"rendered":"\n<p>A star-delta starter is a very common type of starter and is widely used compared to other types of\u00a0induction motor\u00a0starters.<\/p>\n\n\n\n<p>The star-delta starter is used for the squirrel cage induction motor that is designed to run on delta-connected stator winding.<\/p>\n\n\n\n<p>The connection diagram of a start-delta starter for a\u00a0three-phase induction motor\u00a0is shown in the figure below.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\" id=\"attachment_3050\"><img decoding=\"async\" src=\"https:\/\/mdr.foobrdigital.com\/wp-content\/uploads\/2022\/08\/Star-Delta-Starter.png\" alt=\"\" class=\"wp-image-6348\"\/><figcaption>Star-Delta Starter<\/figcaption><\/figure>\n\n\n\n<p>The stator winding is connected in star connection at the time of starting (switch s is connected at START position).<\/p>\n\n\n\n<p>When the motor reaches 80% of rated speed, the changeover switch s thrown quickly to the RUN position. And the stator winding is connected in a delta connection.<\/p>\n\n\n\n<p>During starting condition, the stator winding is connected in a star connection. Hence, the starting current is reduced to one-third as compared to the delta connection.<\/p>\n\n\n\n<p>At the time of starting, stator winding is connected in star connection. Therefore, each stator phase gets a voltage of V<sub>L<\/sub>\/\u221a3 (V<sub>L<\/sub>&nbsp;is line voltage).<\/p>\n\n\n\n<p>Since the torque developed in the motor is directly proportional to the square of the\u00a0voltage, the start-delta starter reduces the starting torque to one-third of that obtained by direct delta starting.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Calculation of Star-delta Starter<\/h2>\n\n\n\n<p>At the time of starting, the stator winding is connected in a star connection. Therefore, the voltage across each phase winding is equal to 1\/\u221a3 times the line voltage.<\/p>\n\n\n\n<p>V<sub>L<\/sub>&nbsp;= Line voltage<\/p>\n\n\n\n<p>I<sub>SYP<\/sub>\u00a0= Starting\u00a0current\u00a0per phase with stator winding connected in star connection<\/p>\n\n\n\n<p>I<sub>SYL<\/sub>&nbsp;= Starting line current with stator winding in star connection<\/p>\n\n\n\n<p><strong>For Star connection<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/mdr.foobrdigital.com\/wp-content\/uploads\/2022\/08\/image-59.png\" alt=\"\" class=\"wp-image-6347\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/mdr.foobrdigital.com\/wp-content\/uploads\/2022\/08\/image-58.png\" alt=\"\" class=\"wp-image-6346\"\/><\/figure>\n\n\n\n<p>V1 = Phase voltage<\/p>\n\n\n\n<p>I<sub>SDP<\/sub>&nbsp;= Starting current per phase by direct switching with stator winding connection in delta connection<\/p>\n\n\n\n<p>I<sub>SDL<\/sub>&nbsp;= Starting line current by direct switching with stator winding connection in delta connection<\/p>\n\n\n\n<p>Z<sub>e10<\/sub>\u00a0= Standstill equivalent impedance per phase of motor referred to stator<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/mdr.foobrdigital.com\/wp-content\/uploads\/2022\/08\/image-57.png\" alt=\"\" class=\"wp-image-6345\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/mdr.foobrdigital.com\/wp-content\/uploads\/2022\/08\/image-56.png\" alt=\"\" class=\"wp-image-6344\"\/><\/figure>\n\n\n\n<p><strong>For delta connection;<\/strong><\/p>\n\n\n\n<p>Line current = \u221a3 x Phase current<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/mdr.foobrdigital.com\/wp-content\/uploads\/2022\/08\/image-55.png\" alt=\"\" class=\"wp-image-6343\"\/><\/figure>\n\n\n\n<p>Now,<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/mdr.foobrdigital.com\/wp-content\/uploads\/2022\/08\/image-54.png\" alt=\"\" class=\"wp-image-6342\"\/><\/figure>\n\n\n\n<p>Therefore, in star-delta starter, the starting current from the main supply is one-third of that with direct switching in delta.<\/p>\n\n\n\n<p>Also, the starting torque is reduced to one-third of the starting torque obtained with direct switching in the delta.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A star-delta starter is a very common type of starter and is widely used compared to other types of\u00a0induction motor\u00a0starters. The star-delta starter is used for the squirrel cage induction motor that is designed to run on delta-connected stator winding. The connection diagram of a start-delta starter for a\u00a0three-phase induction motor\u00a0is shown in the figure [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[359],"tags":[],"_links":{"self":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/19922"}],"collection":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/comments?post=19922"}],"version-history":[{"count":0,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/19922\/revisions"}],"wp:attachment":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/media?parent=19922"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/categories?post=19922"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/tags?post=19922"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}