{"id":17211,"date":"2026-10-29T09:19:07","date_gmt":"2026-10-29T08:19:07","guid":{"rendered":"https:\/\/ventsystems.de\/lexikon\/sicherheitskleinspannung\/"},"modified":"2026-10-29T09:19:07","modified_gmt":"2026-10-29T08:19:07","slug":"safety-extra-low-voltage","status":"publish","type":"page","link":"https:\/\/ventsystems.de\/en\/lexikon\/sicherheitskleinspannung\/","title":{"rendered":"Safety extra-low voltage (SELV)"},"content":{"rendered":"<p class=\"wp-block-paragraph\"><strong>Safety extra-low voltage<\/strong> (SELV) is a voltage so low that touching it normally poses no danger. The limit is 50 V AC or 120 V ripple-free DC. 24 V window actuators operate well below this.<\/p>\n\n\n<h2 class=\"wp-block-heading\">What does this mean in practice?<\/h2>\n\n\n<ul class=\"wp-block-list\"><li>Only extra-low voltage is present at the actuator and on the cable to the window<\/li><li>this is an advantage for windows within reach of people, e.g. in schools or living spaces<\/li><li>the power supply or control, however, is connected to 230 V \u2013 this is done by a qualified electrician<\/li><\/ul>\n\n\n<h2 class=\"wp-block-heading\">Prerequisite<\/h2>\n\n\n<p class=\"wp-block-paragraph\">Genuine safety extra-low voltage is only produced by a suitable safety transformer or power supply with safe isolation. Any power supply is not enough.<\/p>\n\n\n<h2 class=\"wp-block-heading\">Frequently asked questions<\/h2>\n\n\n<h3 class=\"wp-block-heading\">May I install 24 V cables myself?<\/h3>\n\n\n<p class=\"wp-block-paragraph\">The extra-low voltage side is less dangerous, but planning and connection should still be checked by a specialist. The 230 V connection of the power supply or control is always a job for a qualified electrician.<\/p>\n\n\n<h3 class=\"wp-block-heading\">Is 24 V always the better choice?<\/h3>\n\n\n<p class=\"wp-block-paragraph\">Not always. For a single window, a 230 V actuator is simpler. More in the guide 24 V or 230 V.<\/p>\n\n\n<h2 class=\"wp-block-heading\">Read more<\/h2>\n\n\n<ul class=\"wp-block-list\"><li><a href=\"\/en\/window-actuator-24v-or-230v\/\">Guide: Window actuator 24 V or 230 V?<\/a><\/li><li><a href=\"\/en\/dictionary\/24-v-power-supply\/\">Glossary: 24 V power supply<\/a><\/li><li><a href=\"\/en\/dictionary\/cable-cross-section\/\">Glossary: Cable cross-section<\/a><\/li><\/ul>\n\n\n<p class=\"wp-block-paragraph\">Not sure which actuator fits? Call us at <a href=\"tel:+494050694631\">040 50694631<\/a> (Mon\u2013Fri 8 am\u20135 pm) or use the <a href=\"\/en\/drive-finder\/\">actuator finder<\/a>.<\/p>\n\n\n<p class=\"wp-block-paragraph\"><a href=\"\/en\/dictionary\/\">\u2190 Back to the glossary<\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>What safety extra-low voltage means and why 24 V window actuators use it.<\/p>","protected":false},"author":9,"featured_media":0,"parent":16230,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-17211","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/ventsystems.de\/en\/wp-json\/wp\/v2\/pages\/17211","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ventsystems.de\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/ventsystems.de\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/ventsystems.de\/en\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"https:\/\/ventsystems.de\/en\/wp-json\/wp\/v2\/comments?post=17211"}],"version-history":[{"count":0,"href":"https:\/\/ventsystems.de\/en\/wp-json\/wp\/v2\/pages\/17211\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/ventsystems.de\/en\/wp-json\/wp\/v2\/pages\/16230"}],"wp:attachment":[{"href":"https:\/\/ventsystems.de\/en\/wp-json\/wp\/v2\/media?parent=17211"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}