1.0Electrical Riddlehttps://electrical-riddle.com/envahidhttps://electrical-riddle.com/en/author/vahid/rich600338<blockquote class="wp-embedded-content" data-secret="iiVK1Okvwj"><a href="https://electrical-riddle.com/en/forums/reply/8358/">Reply To: Protection riddle no. 10 – Differential protection and auto transfer system</a></blockquote><iframe sandbox="allow-scripts" security="restricted" src="https://electrical-riddle.com/en/forums/reply/8358/embed/#?secret=iiVK1Okvwj" width="600" height="338" title="“Reply To: Protection riddle no. 10 – Differential protection and auto transfer system” — Electrical Riddle" data-secret="iiVK1Okvwj" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" class="wp-embedded-content"></iframe><script> /*! This file is auto-generated */ !function(d,l){"use strict";l.querySelector&&d.addEventListener&&"undefined"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!/[^a-zA-Z0-9]/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret="'+t.secret+'"]'),o=l.querySelectorAll('blockquote[data-secret="'+t.secret+'"]'),c=new RegExp("^https?:$","i"),i=0;i<o.length;i++)o[i].style.display="none";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute("style"),"height"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):"link"===t.message&&(r=new URL(s.getAttribute("src")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener("message",d.wp.receiveEmbedMessage,!1),l.addEventListener("DOMContentLoaded",function(){for(var e,t,s=l.querySelectorAll("iframe.wp-embedded-content"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute("data-secret"))||(t=Math.random().toString(36).substring(2,12),e.src+="#?secret="+t,e.setAttribute("data-secret",t)),e.contentWindow.postMessage({message:"ready",secret:t},"*")},!1)))}(window,document); //# sourceURL=https://electrical-riddle.com/wp-includes/js/wp-embed.min.js </script> it seems that u have a big problem in signal interfaces between MV and LV feeder. according to this type of systems there should be an inter lock between upstream and downstream CB. if the MV CB trip or open in any reason the lv CB should be open too . in some circuit we … Read More »