{"id":163,"date":"2022-01-19T13:11:49","date_gmt":"2022-01-19T18:11:49","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/?post_type=chapter&#038;p=163"},"modified":"2022-07-18T12:19:27","modified_gmt":"2022-07-18T16:19:27","slug":"ballast-noise-rating","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/chapter\/ballast-noise-rating\/","title":{"raw":"Ballast noise rating","rendered":"Ballast noise rating"},"content":{"raw":"<p style=\"text-align: center\"><em>Q: Why do Ballasts \u201chum\u201d?<\/em><\/p>\r\n<p style=\"text-align: center\"><em>A: Because they don\u2019t know the words!<\/em><\/p>\r\nBallasts are given a noise rating, from \u201cA\u201d being the quietest in operation, to \u201cF\u201d being the loudest. In noisy environments it might be acceptable to have louder ballasts in operation, but for general office and institution lighting the constant \u201chum\u201d of a noisy ballast can be distracting and annoying for people nearby.\r\n\r\nThe noise is produced by tiny expansions and contractions of the ferrous metal that is affected by the constantly changing magnetic field produced in <strong>core and coil ballasts<\/strong>, in a process call <strong>magnetostriction<\/strong>. This noise is the conversion of electrical energy into sound and represents a loss of energy.\r\n\r\nModern <strong>electronic ballasts<\/strong> have a very quiet operation as there is no oscillating magnetic circuit to vibrate the metal housing.","rendered":"<p style=\"text-align: center\"><em>Q: Why do Ballasts \u201chum\u201d?<\/em><\/p>\n<p style=\"text-align: center\"><em>A: Because they don\u2019t know the words!<\/em><\/p>\n<p>Ballasts are given a noise rating, from \u201cA\u201d being the quietest in operation, to \u201cF\u201d being the loudest. In noisy environments it might be acceptable to have louder ballasts in operation, but for general office and institution lighting the constant \u201chum\u201d of a noisy ballast can be distracting and annoying for people nearby.<\/p>\n<p>The noise is produced by tiny expansions and contractions of the ferrous metal that is affected by the constantly changing magnetic field produced in <strong>core and coil ballasts<\/strong>, in a process call <strong>magnetostriction<\/strong>. This noise is the conversion of electrical energy into sound and represents a loss of energy.<\/p>\n<p>Modern <strong>electronic ballasts<\/strong> have a very quiet operation as there is no oscillating magnetic circuit to vibrate the metal housing.<\/p>\n","protected":false},"author":848,"menu_order":2,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":["aaron"],"pb_section_license":""},"chapter-type":[],"contributor":[60],"license":[],"class_list":["post-163","chapter","type-chapter","status-publish","hentry","contributor-aaron"],"part":153,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/wp-json\/pressbooks\/v2\/chapters\/163","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/wp-json\/wp\/v2\/users\/848"}],"version-history":[{"count":2,"href":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/wp-json\/pressbooks\/v2\/chapters\/163\/revisions"}],"predecessor-version":[{"id":364,"href":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/wp-json\/pressbooks\/v2\/chapters\/163\/revisions\/364"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/wp-json\/pressbooks\/v2\/parts\/153"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/wp-json\/pressbooks\/v2\/chapters\/163\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/wp-json\/wp\/v2\/media?parent=163"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/wp-json\/pressbooks\/v2\/chapter-type?post=163"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/wp-json\/wp\/v2\/contributor?post=163"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/basiclightingforelectricianslevel2\/wp-json\/wp\/v2\/license?post=163"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}