{"id":3906,"date":"2021-01-10T09:00:48","date_gmt":"2021-01-10T17:00:48","guid":{"rendered":"https:\/\/www.linquip.com\/blog\/?p=3906"},"modified":"2025-08-28T01:21:01","modified_gmt":"2025-08-28T09:21:01","slug":"polarity-test","status":"publish","type":"post","link":"https:\/\/www.linquip.com\/blog\/polarity-test\/","title":{"rendered":"Polarity Test: All You Should Know About"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_82_2 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.linquip.com\/blog\/polarity-test\/#What_Is_the_Polarity_Test\" >What Is the Polarity Test?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.linquip.com\/blog\/polarity-test\/#Why_Do_a_Polarity_Test\" >Why Do a Polarity Test?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.linquip.com\/blog\/polarity-test\/#What_are_the_Polarity_Testing_Methods\" >What are the Polarity Testing Methods?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.linquip.com\/blog\/polarity-test\/#Types_of_Polarity_Testing_of_Transformer\" >Types of\u00a0Polarity Testing of Transformer<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.linquip.com\/blog\/polarity-test\/#Practical_Procedure_for_Testing_of_Transformer\" >Practical Procedure for Testing of Transformer<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.linquip.com\/blog\/polarity-test\/#Polarity_Test_of_Lighting_Circuit\" >Polarity Test of Lighting Circuit<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.linquip.com\/blog\/polarity-test\/#Polarity_Test_of_Induction_Motor\" >Polarity Test of Induction Motor<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.linquip.com\/blog\/polarity-test\/#Download_Polarity_Test_PDF\" >Download Polarity Test PDF<\/a><\/li><\/ul><\/nav><\/div>\n<p>The process of the polarity test is vital in a variety of applications. Typically, when a current flow exists in a conductor, there is always a doubt whether it is a neutral or a phase. For this, an electric tester is employed to check the wire. For example, when we examine the two terminals of the batteries, one performs like a positive and the other one works as a negative terminal which is recognized as a DC supply.<\/p>\n<p>However, here, the flow of current comprises only a single way which does not rotate. In the AC supply, the current direction is inverted for each cycle because the current direction is not constant here. Therefore, for any device&#8217;s operation, its terminals&#8217; polarities must be identified for proper connections. For example, if appropriate connections are not made in a house without experiencing a polarity test, it may end in a short-circuit. So, to avoid such situations, we manage a polarity test for every device prior to its operation.<\/p>\n<p><span style=\"font-weight: 400;\">Get information about the polarity test on Linquip&#8217;s website and discover everything you need to know about it. In case you have any questions concerning polarity testing, Linquip&#8217;s experts in power transmission and distribution are available to answer them. It is advisable that you first read Linquip&#8217;s article entitled &#8220;<\/span><a href=\"https:\/\/www.linquip.com\/industrial-directories\/400\/electrical-power-transmission\"><b>What Is an Electrical Power Transmission?<\/b><\/a><span style=\"font-weight: 400;\">&#8220;.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">We are offering you the opportunity to join Linquip as an<\/span><a href=\"https:\/\/www.linquip.com\/experts\/leaderboard\"> <b>Expert<\/b><\/a><span style=\"font-weight: 400;\"> and access the full range of benefits Linquip offers. Are you interested in writing a<\/span><a href=\"https:\/\/www.linquip.com\/blog\/user-guest-post\"> <b>Guest Post<\/b><\/a><span style=\"font-weight: 400;\"> on Linquip? If so, you can do that by submitting your content as a guest on the Linquip platform.<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_Is_the_Polarity_Test\"><\/span><strong>What Is the Polarity Test? <\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>It is a test carried on both the primary and secondary windings of a <a href=\"https:\/\/www.linquip.com\/blog\/types-of-transformer-construction-and-design\/\">transformer<\/a> and also to identify the direction of the current. It assists in inter-connecting the primary winding and secondary windings in the case of the transformer&#8217;s parallel operation.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Why_Do_a_Polarity_Test\"><\/span><strong>Why Do a Polarity Test? <\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The<strong>\u00a0polarity test&#8217;s importance<\/strong> is that by identifying the polarity of various windings, we can avoid short-circuits while operating the transformers in parallel.<\/p>\n<p>To reach peak demands, the transformers are joined in parallel to perform. For the transformer&#8217;s parallel operation, the polarity of the transformer windings must be distinguished, i.e. both primary and secondary winding.<\/p>\n<p>The principal winding having a positive terminal should be attached to the positive terminal of a primary winding of the other transformer. Furthermore, secondary winding having identical polarity terminals should be attached.<\/p>\n<p>The primary winding has a positive terminal, joined to the negative terminal of the other transformer primary winding. Then, the short circuit of the winding takes place which destroys the entire device. This is why a polarity test is accomplished on the transformer for decent parallel operation.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_are_the_Polarity_Testing_Methods\"><\/span><strong>What are the Polarity Testing Methods?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>There are various methods for polarity test, which are described below:<\/p>\n<h3><strong>Employing a Multimeter<\/strong><\/h3>\n<p>A multimeter finds the voltage at different terminals. The multimeter has two probes, including red and black. The red probe is embedded to the line and the other to the neutral if the pointer gives any deflection, we can assume it as a Line (L). If not, check by attaching the probes to the other terminals one after the other and recognize the deflection. The multimeter type method of finding the polarity is presented in the figure below.<\/p>\n<figure id=\"attachment_3907\" aria-describedby=\"caption-attachment-3907\" style=\"width: 480px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-3907 size-full\" src=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_2.jpg\" alt=\"polarity test\" width=\"480\" height=\"263\" title=\"\" srcset=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_2.jpg 480w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_2-300x164.jpg 300w\" sizes=\"(max-width: 480px) 100vw, 480px\" \/><figcaption id=\"caption-attachment-3907\" class=\"wp-caption-text\">Mains Voltage Polarity Test (Reference: <strong>watelectrical.com<\/strong>)<\/figcaption><\/figure>\n<h3><strong>By knowing the resistance value<\/strong><\/h3>\n<p>One can obtain the resistance of the windings and can resolve the polarity. The Earth wire has lower resistance in comparison with the Line. Earth wire has to keep low resistance compared to the Line (L) to divert surge currents in a short-circuit case.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Types_of_Polarity_Testing_of_Transformer\"><\/span><strong>Types of\u00a0Polarity Testing of Transformer<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>There are generally two types of polarity testing of transformer:<\/p>\n<ul>\n<li>Additive<\/li>\n<li>Subtractive<\/li>\n<\/ul>\n<h3><strong>Additive Polarity<\/strong><\/h3>\n<p>In this method, the voltmeters V<sub>1<\/sub> and V<sub>2<\/sub> are connected across the transformer&#8217;s primary and secondary windings. The voltmeter V<sub>1<\/sub> marks the voltage across the primary winding, whereas voltmeter V<sub>2<\/sub> marks the secondary winding voltage. Aside from these two voltmeters, a third voltmeter V<sub>3<\/sub> is attached across both the windings, i.e., the primary winding and secondary winding. If V<sub>3<\/sub> indicates voltage as the summation of both V<sub>1<\/sub> and V<sub>2<\/sub>, it is an additive type.<\/p>\n<p>The primary winding and the secondary winding polarities are varied. The terminals A<sub>1<\/sub> and B<sub>2<\/sub> have identical polarity, whereas A<sub>2<\/sub> and B<sub>1<\/sub> have similar polarity. The figure which describes the Additive type polarity is exhibited in the figure below.<\/p>\n<figure id=\"attachment_3908\" aria-describedby=\"caption-attachment-3908\" style=\"width: 333px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-3908 size-full\" src=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_3.png\" alt=\"polarity test\" width=\"333\" height=\"300\" title=\"\" srcset=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_3.png 333w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_3-300x270.png 300w\" sizes=\"(max-width: 333px) 100vw, 333px\" \/><figcaption id=\"caption-attachment-3908\" class=\"wp-caption-text\">Schematic of an Additive Polarity Test (Reference: <strong>watelectrical.com<\/strong>)<\/figcaption><\/figure>\n<h3><strong>Subtractive Polarity <\/strong><\/h3>\n<p>The voltmeters V<sub>1<\/sub> and V<sub>2<\/sub> are joined across the transformer primary and secondary windings. The voltmeter V<sub>1<\/sub> marks the voltage across the primary winding, whereas voltmeter V<sub>2<\/sub> marks the secondary winding voltage. Aside from these two voltmeters, a third voltmeter V<sub>3<\/sub> is attached across both the windings, including a primary winding and secondary winding. If V<sub>3<\/sub> reads voltage as the difference between both V<sub>1<\/sub> and V<sub>2<\/sub>, it is a subtractive type.<\/p>\n<p>The primary winding and the secondary winding polarities are identical. The terminals A<sub>1<\/sub> and A<sub>2<\/sub> have identical polarity, whereas B<sub>1<\/sub> and B<sub>2<\/sub> have the same polarity. The figure which illustrates the subtractive type polarity is displayed in the figure below.<\/p>\n<figure id=\"attachment_3909\" aria-describedby=\"caption-attachment-3909\" style=\"width: 305px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-3909 size-full\" src=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_4.png\" alt=\"polarity test\" width=\"305\" height=\"300\" title=\"\" srcset=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_4.png 305w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_4-300x295.png 300w\" sizes=\"(max-width: 305px) 100vw, 305px\" \/><figcaption id=\"caption-attachment-3909\" class=\"wp-caption-text\">Schematic of a Subtractive Polarity Test (Reference: <strong>watelectrical.com<\/strong>)<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Practical_Procedure_for_Testing_of_Transformer\"><\/span><strong>Practical Procedure for Testing of Transformer <\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Equipment needed for the effective testing of the transformer is an auto-transformer, voltmeters, and a transformer.<\/p>\n<p>Functionally connect the primary winding of the transformer to an auto-transformer. The effective working figure of a polarity test on the transformer is given in the figure below.<\/p>\n<figure id=\"attachment_3910\" aria-describedby=\"caption-attachment-3910\" style=\"width: 427px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-3910 size-full\" src=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_5.png\" alt=\"polarity test\" width=\"427\" height=\"300\" title=\"\" srcset=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_5.png 427w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_5-300x211.png 300w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_5-100x70.png 100w\" sizes=\"(max-width: 427px) 100vw, 427px\" \/><figcaption id=\"caption-attachment-3910\" class=\"wp-caption-text\">Schematic of a Practical Polarity Test Diagram (Reference: <strong>watelectrical.com<\/strong>)<\/figcaption><\/figure>\n<p>The procedure of a practical polarity test is as follows:<\/p>\n<ul>\n<li>Attach the first voltmeter across the primary winding and the second voltmeter across the secondary winding. The third voltmeter is then attached across the two windings.<\/li>\n<li>Gradually change the auto-transformer to its rated value, we recognize the voltmeter readings start to change.<\/li>\n<li>Remark all the readings of voltmeters. From the values of voltmeters, we can achieve whether the polarity is additive or subtractive.<\/li>\n<li>If the third voltmeter&#8217;s reading is the addition of both voltmeters, it is an additive type.<\/li>\n<li>If the third voltmeter reading is subtractive of both voltmeters, then it is a subtractive type.<\/li>\n<\/ul>\n<p>The following precautions must be taken into account in a polarity test of a transformer:<\/p>\n<ul>\n<li>Examine the practical connections are not loose.<\/li>\n<li>Do not wire during operation.<\/li>\n<\/ul>\n<p>When we look into the procedures of the\u00a0<a href=\"https:\/\/www.electrical4u.com\/distribution-transformer-efficiency-of-distribution-transformer-all-day-efficiency\/\" target=\"_blank\" rel=\"noopener\"><span data-preserver-spaces=\"true\">distribution transformers<\/span><\/a><span data-preserver-spaces=\"true\">, we discover that they require to work all the time and also demand to supply at high need at peak times. So, to cope up with these conditions, we connect the transformers in parallel.<\/span><\/p>\n<p>Paralleling is made by joining the same polarity terminals of the primary winding together. A similar method is done for the secondary winding. Paralleling will enhance the power supplying capacity and also the system reliability.<\/p>\n<figure id=\"attachment_3911\" aria-describedby=\"caption-attachment-3911\" style=\"width: 534px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-3911 size-full\" src=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_6.png\" alt=\"polarity test\" width=\"534\" height=\"400\" title=\"\" srcset=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_6.png 534w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_6-300x225.png 300w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_6-80x60.png 80w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_6-160x120.png 160w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_6-265x198.png 265w\" sizes=\"(max-width: 534px) 100vw, 534px\" \/><figcaption id=\"caption-attachment-3911\" class=\"wp-caption-text\">Schematic of a Proper Paralleling (Reference: <strong>electrical4u.com<\/strong>)<\/figcaption><\/figure>\n<p>We do\u00a0<strong><span data-preserver-spaces=\"true\">polarity tests<\/span><\/strong><span data-preserver-spaces=\"true\">\u00a0on parallel transformers to guarantee that we join the same polarity windings and not the opposite ones. If we inadvertently connect the opposite polarities of the windings, it will end in a short-circuit and ultimately damage the machine.<\/span><\/p>\n<figure id=\"attachment_3912\" aria-describedby=\"caption-attachment-3912\" style=\"width: 534px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-3912 size-full\" src=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_7.png\" alt=\"polarity test\" width=\"534\" height=\"400\" title=\"\" srcset=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_7.png 534w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_7-300x225.png 300w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_7-80x60.png 80w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_7-160x120.png 160w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_7-265x198.png 265w\" sizes=\"(max-width: 534px) 100vw, 534px\" \/><figcaption id=\"caption-attachment-3912\" class=\"wp-caption-text\">Schematic of an Improper Paralleling (Reference: <strong>electrical4u.com<\/strong>)<\/figcaption><\/figure>\n<p>Suppose we require additive polarity but we have subtractive polarity. In this situation, we can easily change it by holding either of the primary or secondary windings in the same fashion and converting the other one&#8217;s winding connection. Similarly, if we need subtractive polarity but have additive polarity, we could do the same procedure as above.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Polarity_Test_of_Lighting_Circuit\"><\/span><strong>Polarity Test of Lighting Circuit <\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A\u00a0<strong><span data-preserver-spaces=\"true\">polarity test for a lighting circuit<\/span><\/strong><span data-preserver-spaces=\"true\"> must be made when fresh or after a change has been made. This test ensures that the phase-conductor is linked to<\/span><a href=\"https:\/\/www.elprocus.com\/difference-between-mcb-mccb-elcb-rccb\/\" target=\"_blank\" rel=\"noopener\"><span data-preserver-spaces=\"true\">\u00a0the MCB<\/span><\/a><span data-preserver-spaces=\"true\">\u00a0or FUSE, and only pole switches, alternately the neutral. In the below figure, any type of Edison-Screw light holder must be tested to ensure that the phase-conductor is linked with the center contact and the neutral to the contact of the screw.<\/span><\/p>\n<figure id=\"attachment_3913\" aria-describedby=\"caption-attachment-3913\" style=\"width: 476px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-3913 size-full\" src=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_9.jpg\" alt=\"polarity test\" width=\"476\" height=\"250\" title=\"\" srcset=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_9.jpg 476w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_9-300x158.jpg 300w\" sizes=\"(max-width: 476px) 100vw, 476px\" \/><figcaption id=\"caption-attachment-3913\" class=\"wp-caption-text\">Schematic of a Polarity Test of Lighting Circuit (Reference: <strong>machineryequipmentonline.com<\/strong>)<\/figcaption><\/figure>\n<p>Disconnect the fuse from the circuit or discharge MCB (miniature circuit breaker). Take away all lamps from the relevant circuit. Connect one finish of the long trailing terminal to the departing terminal of the MCB circuit.<\/p>\n<p>By another end, in combination with the test meter terminals, write down the readings from the phase lead at all the tips in the circuit region. For example, ES light holders stability at each end assures that polarity is correct. If the power supply is disconnected from the setting up, the long trailing terminal may be allied to the phase busbar, and the small circuit breaker must be left in the position of \u2018ON\u2019.<\/p>\n<figure id=\"attachment_3914\" aria-describedby=\"caption-attachment-3914\" style=\"width: 507px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-3914 size-full\" src=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_10.jpg\" alt=\"polarity test\" width=\"507\" height=\"293\" title=\"\" srcset=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_10.jpg 507w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_10-300x173.jpg 300w\" sizes=\"(max-width: 507px) 100vw, 507px\" \/><figcaption id=\"caption-attachment-3914\" class=\"wp-caption-text\">Schematic of a Polarity Test of Lighting Circuit (Reference: <strong>machineryequipmentonline.com<\/strong>)<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Polarity_Test_of_Induction_Motor\"><\/span><strong>Polarity Test of Induction Motor <\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Carrying Polarity test of new three phase Induction motor is inevitable before going into operation. If the wrong polarity motor is provided with three phase supply, the magnetic field configuration within the motor windings becomes uneven, and the output torque becomes pulsating. The motor draws excessive currents, which leads to damage to the windings.<\/p>\n<p>If we have a new Induction motor without any sense of the leads, we must identify its polarity before utilizing it. Ordinarily, six terminals from the three phases of an induction motor are available. If their polarity markings (A1, A2; B1, B2; C1, C2) are unknown, these can be located out by a polarity test on the induction motor.<\/p>\n<h3><strong>Methods of Polarity Test of Induction Motor<\/strong><\/h3>\n<p>There are two ways to distinguish the Polarity of three phase Induction motor:<\/p>\n<ol>\n<li>Discovering polarity by Using A.C supply<\/li>\n<li>Discovering Polarity by Using D.C supply<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<h4><em>Finding Polarity of Induction Motor-Method I (by A.C) <\/em><\/h4>\n<p>The following equipment is required:<\/p>\n<ol>\n<li>Six terminal Induction motor<\/li>\n<li>Multimeter or Continuity Tester<\/li>\n<li>Single-phase A.C supply<\/li>\n<li>A.C Voltmeter<\/li>\n<\/ol>\n<p>The aforementioned procedure is explained here:<\/p>\n<h5><em>Step 1: Continuity test to identify each of the winding terminals [AA BB CC]<\/em><\/h5>\n<p>We can do this test with the guidance of a multimeter by monitoring continuity between any two terminals. If the two terminals belong to the same winding, a beep will happen.<\/p>\n<p>Do this method for all and identify terminals, then note the terminals as AA, BB, and CC.<\/p>\n<h5><em>Step 2: Test to identify polarities [A1A2 B1B2 C1C2]<\/em><\/h5>\n<p>Take any two windings randomly and note the terminals as A1 A2, B1 B2 (this is the assumption) as given in the figure.<\/p>\n<figure id=\"attachment_3915\" aria-describedby=\"caption-attachment-3915\" style=\"width: 221px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-3915 size-full\" src=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_11.jpg\" alt=\"polarity test\" width=\"221\" height=\"141\" title=\"\"><figcaption id=\"caption-attachment-3915\" class=\"wp-caption-text\">Schematic of A.C Method of Finding Polarity -1 (Reference: <strong>instrumentationforum.com<\/strong>)<\/figcaption><\/figure>\n<p>Now connect A2 to B1 so that the two windings are in series.<\/p>\n<p>Now employ 230V A.C between A1 and A2 and regulate the voltage across A1 and B2.<\/p>\n<p>If we notice the determined voltage is less than the employed voltage, then our assumption is right. Otherwise, interchange the terminals A1 and A2 and replicate the process to find the terminals A1, A2, B1, and B2.<\/p>\n<p>Now take the third winding mark as C1, C2 (this is the assumption) and take the second winding B1B2 (already known) connect B2 to C1 so that the two windings are in series as shown in the figure below.<\/p>\n<figure id=\"attachment_3916\" aria-describedby=\"caption-attachment-3916\" style=\"width: 242px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-3916 size-full\" src=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_12.jpg\" alt=\"polarity test\" width=\"242\" height=\"153\" title=\"\"><figcaption id=\"caption-attachment-3916\" class=\"wp-caption-text\">Schematic of A.C Method of Finding Polarity- 2 (Reference: <strong>instrumentationforum.com<\/strong>)<\/figcaption><\/figure>\n<p>Now apply 230V A.C among B1 and B2 and determine the voltage across B1 and C2.<\/p>\n<p>If we notice that the determined voltage is less than the applied voltage, then our assumption is right. Otherwise, interchange the terminals C1 and C2 and replicate the process to find the terminals B1, B2, C1, and C2.<\/p>\n<p>Once we can recognize all the terminals, they are joined for Star or Delta fashion; for star connection, join A2B2C2 or A1B1C1; for delta connection, connect A2B1, B2C1, and A1C2.<\/p>\n<h4><em>Finding Polarity of Induction Motor-Method II (by D.C) <\/em><\/h4>\n<p>The following equipment is required:<\/p>\n<ol>\n<li>Center \u2013 zero galvanometer or milli voltmeter or milli ammeter<\/li>\n<li>Switch and wires<\/li>\n<li>Battery (1.5V or 3V)<\/li>\n<\/ol>\n<h5><em>Procedure to identify terminals A1, A2 and B1, B2 <\/em><\/h5>\n<figure id=\"attachment_3917\" aria-describedby=\"caption-attachment-3917\" style=\"width: 515px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-3917 size-full\" src=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_13.png\" alt=\"polarity test\" width=\"515\" height=\"382\" title=\"\" srcset=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_13.png 515w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_13-300x223.png 300w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_13-485x360.png 485w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_13-80x60.png 80w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_13-160x120.png 160w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_13-265x198.png 265w\" sizes=\"(max-width: 515px) 100vw, 515px\" \/><figcaption id=\"caption-attachment-3917\" class=\"wp-caption-text\">Schematic of D.C. Method of Finding Polarity- 1 (Reference: <strong>instrumentationforum.com<\/strong>)<\/figcaption><\/figure>\n<ol>\n<li>Randomly pick one of the phase winding terminals, say A1 and A2.<\/li>\n<li>Attach the positive terminal of the battery to A1 and the negative terminal to A2 through a switch.<\/li>\n<li>The meter is attached across one of the other two-phase windings, say B phase randomly.<\/li>\n<li>At the moment of closing the switch, recognize the deflection of the meter pointer.<\/li>\n<li>If there is a positive or clockwise deflection, then the terminal attached to the positive meter is B2, and connected to the negative terminal is B1.<\/li>\n<li>If the deflection is in the reverse direction, then the polarities are B1 and B2, respectively.<\/li>\n<\/ol>\n<h5><em>Procedure to identify other terminals C1, C2 <\/em><\/h5>\n<figure id=\"attachment_3918\" aria-describedby=\"caption-attachment-3918\" style=\"width: 515px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-3918 size-full\" src=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_14.png\" alt=\"polarity test\" width=\"515\" height=\"382\" title=\"\" srcset=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_14.png 515w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_14-300x223.png 300w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_14-485x360.png 485w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_14-80x60.png 80w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_14-160x120.png 160w, https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2020\/12\/polarity_test_14-265x198.png 265w\" sizes=\"(max-width: 515px) 100vw, 515px\" \/><figcaption id=\"caption-attachment-3918\" class=\"wp-caption-text\">Schematic of D.C. Method of Finding Polarity- 2 (Reference: <strong>instrumentationforum.com<\/strong>)<\/figcaption><\/figure>\n<ol>\n<li>Pick the first winding with terminals, say A1 and A2.<\/li>\n<li>Attach the positive terminal of the battery to A1 and the negative terminal to A2 through a switch.<\/li>\n<li>The meter is joined across the third phase winding.<\/li>\n<li>At the moment of closing the switch, recognize the deflection of the meter pointer.<\/li>\n<li>If there is a positive or clockwise deflection, then the terminal attached to the positive meter is C2, and connected to the negative terminal is C1.<\/li>\n<li>If the deflection is in the reverse direction, then the polarities are C1 and C2, respectively.<\/li>\n<\/ol>\n<h2><span class=\"ez-toc-section\" id=\"Download_Polarity_Test_PDF\"><\/span><b>Download Polarity Test PDF<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400;\">If you would like to access a PDF version of this article, please click on the download link below.<\/span><\/p>\n<div class=\"su-button-center\"><a href=\"https:\/\/www.linquip.com\/blog\/wp-content\/uploads\/2021\/01\/linquip.com-Polarity-Test-All-You-Should-Know-About.pdf\" class=\"su-button su-button-style-default su-button-wide\" style=\"color:#FFFFFF;background-color:#2D89EF;border-color:#246ec0;border-radius:12px\" target=\"_blank\" rel=\"noopener noreferrer\"><span style=\"color:#FFFFFF;padding:0px 30px;font-size:22px;line-height:44px;border-color:#6cadf4;border-radius:12px;text-shadow:none\"> Download PDF<\/span><\/a><\/div>\n<h3><b>Buy Equipment or Ask for a Service<\/b><\/h3>\n<p>By using Linquip RFQ Service, you can expect\u00a0to receive quotations from various suppliers across multiple industries and regions.<\/p>\n<p style=\"text-align: center;\"><strong><a href=\"http:\/\/linquip.com\/get-quote?utm_source=blog&amp;utm_medium=content&amp;utm_campaign=product_list&amp;utm_term=product_list&amp;utm_content=rfq\" target=\"_blank\" rel=\"noopener\">Click Here to Request a Quotation From Suppliers and Service Providers<\/a><\/strong><\/p>\n<p><strong><em>Read More In Linquip<\/em><\/strong><\/p>\n<ul>\n<li><span style=\"text-decoration: underline;\"><strong><span style=\"font-size: 10pt; 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Typically, when a current flow exists in a conductor, there is always a doubt whether it is a neutral or a phase. For this, an electric tester is employed to check the wire. For example, when we examine the two terminals of &#8230;<\/p>\n","protected":false},"author":11,"featured_media":3919,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","footnotes":""},"categories":[21],"tags":[],"class_list":["post-3906","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-electrical-component"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.linquip.com\/blog\/wp-json\/wp\/v2\/posts\/3906","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.linquip.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.linquip.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.linquip.com\/blog\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/www.linquip.com\/blog\/wp-json\/wp\/v2\/comments?post=3906"}],"version-history":[{"count":6,"href":"https:\/\/www.linquip.com\/blog\/wp-json\/wp\/v2\/posts\/3906\/revisions"}],"predecessor-version":[{"id":36547,"href":"https:\/\/www.linquip.com\/blog\/wp-json\/wp\/v2\/posts\/3906\/revisions\/36547"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.linquip.com\/blog\/wp-json\/wp\/v2\/media\/3919"}],"wp:attachment":[{"href":"https:\/\/www.linquip.com\/blog\/wp-json\/wp\/v2\/media?parent=3906"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.linquip.com\/blog\/wp-json\/wp\/v2\/categories?post=3906"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.linquip.com\/blog\/wp-json\/wp\/v2\/tags?post=3906"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}