{"id":98,"date":"2020-01-13T13:40:10","date_gmt":"2020-01-13T18:40:10","guid":{"rendered":"https:\/\/opentextbc.ca\/basicmotorcontrol\/chapter\/numbering-system\/"},"modified":"2023-03-02T11:56:12","modified_gmt":"2023-03-02T16:56:12","slug":"numbering-system","status":"publish","type":"chapter","link":"https:\/\/opentextbc.ca\/basicmotorcontrol\/chapter\/numbering-system\/","title":{"raw":"Numbering System","rendered":"Numbering System"},"content":{"raw":"[pb_glossary id=\"242\"]Control circuits[\/pb_glossary] can range from the very simple to the extremely complex. [pb_glossary id=\"245\"]Ladder diagrams[\/pb_glossary] show how a system works and are used for troubleshooting purposes. [pb_glossary id=\"246\"]Wiring diagrams[\/pb_glossary] show where equipment is and how it is connected.\r\n\r\nBeing able to convert from one style of diagram to the other is an essential skill for electricians and people working with control circuits. To accomplish this, we use a simple [pb_glossary id=\"248\"]numbering system[\/pb_glossary].\r\n\r\nThe numbering system is a way of identifying and \u201cnaming\u201d each [pb_glossary id=\"247\"]electrically common[\/pb_glossary] point in a circuit. A wire is considered \u201celectrically common\u201d with another wire if they share a direct electrical connection with no [pb_glossary id=\"236\"]switches[\/pb_glossary] or loads between them.\r\n\r\nConsider the circuit below:\r\n\r\n[caption id=\"attachment_97\" align=\"aligncenter\" width=\"1024\"]<img class=\"size-large wp-image-97\" src=\"https:\/\/opentextbc.ca\/accessibilitytoolkit\/wp-content\/uploads\/sites\/314\/2020\/01\/3-Wire-Number-1-e1579565179355-1024x256.png\" alt=\"\" width=\"1024\" height=\"256\" \/> A three-wire numbered circuit[\/caption]\r\n\r\nIt is a simple three-wire circuit with single stop and start [pb_glossary id=\"235\"]pushbuttons[\/pb_glossary]. Single-phase power is supplied from Lines 1 and 2 and a motor coil is the load.\r\n\r\nStarting at Line 1, we label the first wire \u201c1.\u201d When we jump through the first device, (the [pb_glossary id=\"230\"]normally closed[\/pb_glossary] stop button) we jump up to the next number. Wires 1 and 2 are not electrically common. Coming out of the stop button with wire number 2, we are going to two different places. The first is the [pb_glossary id=\"229\"]normally open[\/pb_glossary] start pushbutton, the other is the normally open instantaneous contact. Since there are no loads or devices between the load side of the stop button, the line side of the start button, and the holding contact, these points are considered electrically common and can all share the same number. Jumping through these devices, wire number 3 is connected to the load side of both normally open devices and the [pb_glossary id=\"227\"]motor starter[\/pb_glossary] itself, and so these three points are also electrically common.\r\n\r\nOnce the control circuit has been numbered, we can use that information to help complete wiring diagrams or determine the number of conductors needed in conduits for installation purposes.\r\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">In summary:<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n<ul>\r\n \t<li>L1 and L2 (or L1 and N) are used to designate the control circuit power.<\/li>\r\n \t<li>Assign number 1 to the first wire entering the control circuit.<\/li>\r\n \t<li>Trace through the [pb_glossary id=\"245\"]schematic diagram[\/pb_glossary] increasing the numbers given to wires each time you pass through a device.<\/li>\r\n \t<li>Give the same number to all wires that are electrically common, spliced, or connected to the same terminal.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\nhttps:\/\/media.bccampus.ca\/id\/0_dxdr3w88?width=608&amp;height=402&amp;playerId=23449753","rendered":"<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_98_242\">Control circuits<\/a> can range from the very simple to the extremely complex. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_98_245\">Ladder diagrams<\/a> show how a system works and are used for troubleshooting purposes. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_98_246\">Wiring diagrams<\/a> show where equipment is and how it is connected.<\/p>\n<p>Being able to convert from one style of diagram to the other is an essential skill for electricians and people working with control circuits. To accomplish this, we use a simple <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_98_248\">numbering system<\/a>.<\/p>\n<p>The numbering system is a way of identifying and \u201cnaming\u201d each <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_98_247\">electrically common<\/a> point in a circuit. A wire is considered \u201celectrically common\u201d with another wire if they share a direct electrical connection with no <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_98_236\">switches<\/a> or loads between them.<\/p>\n<p>Consider the circuit below:<\/p>\n<figure id=\"attachment_97\" aria-describedby=\"caption-attachment-97\" style=\"width: 1024px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-large wp-image-97\" src=\"https:\/\/opentextbc.ca\/accessibilitytoolkit\/wp-content\/uploads\/sites\/314\/2020\/01\/3-Wire-Number-1-e1579565179355-1024x256.png\" alt=\"\" width=\"1024\" height=\"256\" srcset=\"https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-content\/uploads\/sites\/314\/2020\/01\/3-Wire-Number-1-e1579565179355-1024x256.png 1024w, https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-content\/uploads\/sites\/314\/2020\/01\/3-Wire-Number-1-e1579565179355-300x75.png 300w, https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-content\/uploads\/sites\/314\/2020\/01\/3-Wire-Number-1-e1579565179355-768x192.png 768w, https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-content\/uploads\/sites\/314\/2020\/01\/3-Wire-Number-1-e1579565179355-1536x384.png 1536w, https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-content\/uploads\/sites\/314\/2020\/01\/3-Wire-Number-1-e1579565179355-2048x512.png 2048w, https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-content\/uploads\/sites\/314\/2020\/01\/3-Wire-Number-1-e1579565179355-65x16.png 65w, https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-content\/uploads\/sites\/314\/2020\/01\/3-Wire-Number-1-e1579565179355-225x56.png 225w, https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-content\/uploads\/sites\/314\/2020\/01\/3-Wire-Number-1-e1579565179355-350x87.png 350w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption id=\"caption-attachment-97\" class=\"wp-caption-text\">A three-wire numbered circuit<\/figcaption><\/figure>\n<p>It is a simple three-wire circuit with single stop and start <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_98_235\">pushbuttons<\/a>. Single-phase power is supplied from Lines 1 and 2 and a motor coil is the load.<\/p>\n<p>Starting at Line 1, we label the first wire \u201c1.\u201d When we jump through the first device, (the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_98_230\">normally closed<\/a> stop button) we jump up to the next number. Wires 1 and 2 are not electrically common. Coming out of the stop button with wire number 2, we are going to two different places. The first is the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_98_229\">normally open<\/a> start pushbutton, the other is the normally open instantaneous contact. Since there are no loads or devices between the load side of the stop button, the line side of the start button, and the holding contact, these points are considered electrically common and can all share the same number. Jumping through these devices, wire number 3 is connected to the load side of both normally open devices and the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_98_227\">motor starter<\/a> itself, and so these three points are also electrically common.<\/p>\n<p>Once the control circuit has been numbered, we can use that information to help complete wiring diagrams or determine the number of conductors needed in conduits for installation purposes.<\/p>\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">In summary:<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li>L1 and L2 (or L1 and N) are used to designate the control circuit power.<\/li>\n<li>Assign number 1 to the first wire entering the control circuit.<\/li>\n<li>Trace through the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_98_245\">schematic diagram<\/a> increasing the numbers given to wires each time you pass through a device.<\/li>\n<li>Give the same number to all wires that are electrically common, spliced, or connected to the same terminal.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p><iframe loading=\"lazy\" id=\"kaltura_player\" title=\"Numbering System\" src=\"https:\/\/api.ca.kaltura.com\/p\/148\/sp\/14800\/embedIframeJs\/uiconf_id\/23449753\/partner_id\/148?iframeembed=true&#38;playerId=kaltura_player&#38;entry_id=0_dxdr3w88&#38;flashvars[leadWithHTML5]=true&#38;flashvars[streamerType]=auto&#38;flashvars[localizationCode]=en&#38;flashvars[sideBarContainer.plugin]=true&#38;flashvars[sideBarContainer.position]=left&#38;flashvars[sideBarContainer.clickToClose]=true&#38;flashvars[chapters.plugin]=true&#38;flashvars[chapters.layout]=vertical&#38;flashvars[chapters.thumbnailRotator]=false&#38;flashvars[streamSelector.plugin]=true&#38;flashvars[EmbedPlayer.SpinnerTarget]=videoHolder&#38;flashvars[dualScreen.plugin]=true&#38;flashvars[Kaltura.addCrossoriginToIframe]=true&#38;wid=0_69lp6rov\" width=\"608\" height=\"402\" allowfullscreen=\"allowfullscreen\" sandbox=\"allow-downloads allow-forms allow-same-origin allow-scripts allow-top-navigation allow-pointer-lock allow-popups allow-modals allow-orientation-lock allow-popups-to-escape-sandbox allow-presentation allow-top-navigation-by-user-activation\" frameborder=\"0\"><\/iframe><\/p>\n<div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">definition<\/span><template id=\"term_98_242\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_98_242\"><div tabindex=\"-1\"><p>In contrast to the Power Circuit, the Control Circuit consists of inputs, in the form of switches, pushbuttons or pilot devices, which when activated, can either directly, or through a magnetic motor starter, energize a load. The Control Circuit often operates at a lower voltage than the Power Circuit for safety and ease of installation.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_98_245\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_98_245\"><div tabindex=\"-1\"><p>A diagram that shows how a circuit works logically and electrically. It uses symbols to identify components and interconnecting lines to display the electrical continuity of a circuit. It is often used for troubleshooting purposes. Also known as a ladder diagram.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_98_246\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_98_246\"><div tabindex=\"-1\"><p>A diagram shows how equipment is laid out and the connections between them. This type of diagram shows the physical relation of all devices in the system, the conductor terminations between these devices, and are commonly used in motor control installations. Also known as a connection diagram.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_98_248\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_98_248\"><div tabindex=\"-1\"><p>Used to convert between wiring and schematic diagrams, the numbering system is a method of identifying and labelling each electrically common point in a circuit. Two wires are considered electrically common if they share an electrical connection with no switches or loads between them, and so would be assigned the same number in the diagram.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_98_247\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_98_247\"><div tabindex=\"-1\"><p>Referring to two or more points in a circuit which have no loads or switches between them and have no potential difference between them.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_98_236\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_98_236\"><div tabindex=\"-1\"><p>A device for making or breaking the connection in an electric circuit.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_98_235\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_98_235\"><div tabindex=\"-1\"><p>A momentary contact device that has a built in spring to return the button to its normal position once release. Available with either normally-open, normally-closed or both sets of contacts.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_98_230\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_98_230\"><div tabindex=\"-1\"><p>A contact that under normal conditions has continuity through it. When the contact changes its state it interrupts the flow of current by opening its contacts. Can be associated with pushbuttons, pilot devices or magnetic contactors.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_98_229\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_98_229\"><div tabindex=\"-1\"><p>A contact that under normal conditions does not have continuity through it. When the contact changes its state it permits the flow of current by closing its contacts. Can be associated with pushbuttons, pilot devices or magnetic contactors.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_98_227\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_98_227\"><div tabindex=\"-1\"><p>A device that controls the flow of electrical power to a motor. It is designed to safely start and stop a motor, and provide <strong>overload protection<\/strong>.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><\/div>","protected":false},"author":90,"menu_order":2,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-98","chapter","type-chapter","status-publish","hentry"],"part":92,"_links":{"self":[{"href":"https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-json\/pressbooks\/v2\/chapters\/98","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-json\/wp\/v2\/users\/90"}],"version-history":[{"count":3,"href":"https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-json\/pressbooks\/v2\/chapters\/98\/revisions"}],"predecessor-version":[{"id":442,"href":"https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-json\/pressbooks\/v2\/chapters\/98\/revisions\/442"}],"part":[{"href":"https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-json\/pressbooks\/v2\/parts\/92"}],"metadata":[{"href":"https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-json\/pressbooks\/v2\/chapters\/98\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-json\/wp\/v2\/media?parent=98"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-json\/pressbooks\/v2\/chapter-type?post=98"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-json\/wp\/v2\/contributor?post=98"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/opentextbc.ca\/basicmotorcontrol\/wp-json\/wp\/v2\/license?post=98"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}