{"id":122,"date":"2026-10-28T10:00:00","date_gmt":"2026-10-28T06:30:00","guid":{"rendered":"https:\/\/sanatiblog.ir\/blog\/which-circuit-breaker\/"},"modified":"2026-10-28T10:00:00","modified_gmt":"2026-10-28T06:30:00","slug":"which-circuit-breaker","status":"publish","type":"post","link":"https:\/\/sanatiblog.ir\/fa\/blog\/which-circuit-breaker\/","title":{"rendered":"\u0641\u06cc\u0648\u0632 \u0645\u06cc\u0646\u06cc\u0627\u062a\u0648\u0631\u06cc\u060c \u06a9\u0644\u06cc\u062f \u0627\u062a\u0648\u0645\u0627\u062a\u06cc\u06a9 \u06cc\u0627 \u062d\u0631\u0627\u0631\u062a\u06cc: \u06a9\u062f\u0627\u0645 \u0631\u0627 \u0628\u062e\u0631\u0645\u061f"},"content":{"rendered":"<p>A breaker cuts the power when too much current flows, before the cable overheats. Four questions pick the right one.<\/p>\n<h2>1. Which kind<\/h2>\n<ul>\n<li><strong>Miniature breaker (MCB):<\/strong> the small DIN-rail breakers, up to about 63 A. For lighting, sockets and small machines.<\/li>\n<li><strong>Moulded case breaker (MCCB):<\/strong> a bigger box for main panels and big loads, from about 16 A to over 1,000 A, often with adjustable settings.<\/li>\n<li><strong>Motor protection breaker:<\/strong> set to the motor&#8217;s nameplate current, it protects the motor against overload and a lost phase.<\/li>\n<\/ul>\n<h2>2. The current<\/h2>\n<p>The breaker&#8217;s current must be no higher than what the cable can carry. The breaker protects the cable, not the device.<\/p>\n<h2>3. The curve: B, C or D<\/h2>\n<p>Starting current is high for a moment, so breakers are made to wait a little:<\/p>\n<ul>\n<li><strong>B:<\/strong> trips at 3\u20135 times the rated current. Heaters and long cables.<\/li>\n<li><strong>C:<\/strong> 5\u201310 times. The usual choice: lighting, sockets, small motors.<\/li>\n<li><strong>D:<\/strong> 10\u201320 times. Transformers and motors with heavy starts.<\/li>\n<\/ul>\n<h2>4. Breaking capacity (kA)<\/h2>\n<p>The biggest short-circuit current the breaker can safely cut. 6 kA is common in buildings; near a big transformer or in a factory, 10 kA or more. Your electrician can tell you what your panel needs.<\/p>\n<h2>And for people: an RCD<\/h2>\n<p>A normal breaker protects cables. To protect people from an electric shock, add a residual current device (RCD) of 30 mA for sockets, bathrooms and outdoor lines.<\/p>\n<p>Tell the seller: the kind, current, curve, number of poles (1P, 1P+N, 3P, 4P) and kA.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u0645\u06cc\u0646\u06cc\u0627\u062a\u0648\u0631\u06cc\u060c \u06a9\u0644\u06cc\u062f \u0627\u062a\u0648\u0645\u0627\u062a\u06cc\u06a9 \u06cc\u0627 \u06a9\u0644\u06cc\u062f \u062d\u0631\u0627\u0631\u062a\u06cc\u061b \u0645\u0646\u062d\u0646\u06cc B\u060c C \u0648 D\u061b \u0648 \u06a9\u06cc\u0644\u0648\u0622\u0645\u067e\u0631.<\/p>\n","protected":false},"author":0,"featured_media":137,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-122","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/posts\/122","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/comments?post=122"}],"version-history":[{"count":0,"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/posts\/122\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/media\/137"}],"wp:attachment":[{"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/media?parent=122"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/categories?post=122"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sanatiblog.ir\/fa\/wp-json\/wp\/v2\/tags?post=122"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}