{"id":20,"date":"2020-12-08T15:36:26","date_gmt":"2020-12-08T20:36:26","guid":{"rendered":"https:\/\/opentextbc.ca\/basichvac\/part\/terms-and-definitions\/"},"modified":"2023-03-02T11:28:33","modified_gmt":"2023-03-02T16:28:33","slug":"terms-and-definitions","status":"publish","type":"part","link":"https:\/\/opentextbc.ca\/basichvac\/part\/terms-and-definitions\/","title":{"raw":"Electrical Terms and Definitions","rendered":"Electrical Terms and Definitions"},"content":{"raw":"Click play on the following audio player to listen along as you read this section.\r\n\r\nhttps:\/\/media.bccampus.ca\/id\/0_chhxfk72?width=608&amp;height=80&amp;playerId=23449753\r\n\r\nWhen discussing HVAC controls, there are two main circuits that we focus on. The first being the <strong>[pb_glossary id=\"182\"]power circuit[\/pb_glossary]<\/strong>. This circuit can be either <strong>[pb_glossary id=\"181\"]single-phase[\/pb_glossary]<\/strong> or <strong>[pb_glossary id=\"180\"]three-phase[\/pb_glossary]<\/strong>, and power the equipment which is doing the work of either heating, cooling or ventilating.\r\n\r\nThe second circuit we will focus on is the <strong>[pb_glossary id=\"179\"]control circuit[\/pb_glossary]<\/strong>. This is the circuit which tells the [pb_glossary id=\"182\"]<strong>power circuit<\/strong>[\/pb_glossary] when to engage. The control circuit will sometimes operate at an <strong>[pb_glossary id=\"204\"]extra-low voltage[\/pb_glossary]<\/strong> value of 24 volts relative to the power circuit, which usually operates at a line voltage value of 240 volts or more.","rendered":"<p>Click play on the following audio player to listen along as you read this section.<\/p>\n<p><iframe loading=\"lazy\" id=\"kaltura_player\" title=\"1.0 Electrical Terms and Definitions\" 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_chhxfk72&#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_b89qywyz\" width=\"608\" height=\"80\" 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<p>When discussing HVAC controls, there are two main circuits that we focus on. The first being the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_20_182\">power circuit<\/a><\/strong>. This circuit can be either <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_20_181\">single-phase<\/a><\/strong> or <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_20_180\">three-phase<\/a><\/strong>, and power the equipment which is doing the work of either heating, cooling or ventilating.<\/p>\n<p>The second circuit we will focus on is the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_20_179\">control circuit<\/a><\/strong>. This is the circuit which tells the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_20_182\"><strong>power circuit<\/strong><\/a> when to engage. The control circuit will sometimes operate at an <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_20_204\">extra-low voltage<\/a><\/strong> value of 24 volts relative to the power circuit, which usually operates at a line voltage value of 240 volts or more.<\/p>\n<div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">definition<\/span><template id=\"term_20_182\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_20_182\"><div tabindex=\"-1\"><p>In contrast to the control circuit, the power circuit provides the large values of voltage and current used by the motor itself. Must be equipped with overcurrent and overload protection, and horsepower-rated contacts in the control gear equal to the voltage and current ratings of the motor.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_20_181\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_20_181\"><div tabindex=\"-1\"><p>The simplest electrical circuit. It requires only two lines: one for power to go in and the other is a return path for current. These are often called Line 1 and Line 2, or Line 1 and Neutral. Current only has one path to travel in a single-phase circuit, such as a control 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_20_180\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_20_180\"><div tabindex=\"-1\"><p>An electrical circuit that uses three current carrying conductors, called Line 1, Line 2, and Line 3, which have a 120\u00b0 phase shift in the voltage and current waveforms between them. The Power Circuit of three-phase motors is an example of a three-phase 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_20_179\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_20_179\"><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_20_204\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_20_204\"><div tabindex=\"-1\"><p>Any voltage not exceeding 30V. Equipment energized at 24 V is commonly referred to as the \"low voltage circuit\".<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><\/div>","protected":false},"parent":0,"menu_order":1,"template":"","meta":{"pb_part_invisible":false,"pb_part_invisible_string":""},"contributor":[],"license":[],"class_list":["post-20","part","type-part","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/pressbooks\/v2\/parts\/20","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/pressbooks\/v2\/parts"}],"about":[{"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/wp\/v2\/types\/part"}],"version-history":[{"count":3,"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/pressbooks\/v2\/parts\/20\/revisions"}],"predecessor-version":[{"id":324,"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/pressbooks\/v2\/parts\/20\/revisions\/324"}],"wp:attachment":[{"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/wp\/v2\/media?parent=20"}],"wp:term":[{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/wp\/v2\/contributor?post=20"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/wp\/v2\/license?post=20"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}