[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-655290-105":59,"doc-detail-655290-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","ladder-diagrams-electrical-control-logic-schematics","Ladder diagrams - Electrical control logic schematics","","Ladder diagrams are specialized schematics used to document industrial electrical control logic, featuring two vertical power rails and horizontal rungs that represent parallel control circuit branches. The text explains the meaning of L1 (hot) and L2 (neutral/grounded), clarifies how wire numbers label electrically continuous points without changing at nodes, and discusses design practice for grounding and fuse placement to prevent dangerous energization. It also shows how contact combinations implement OR, AND, and NOT logic using truth-table style reasoning.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":30,"@type":76,"position":81},"https://docshare.wps.com/document/technology/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/ladder-diagrams-electrical-control-logic-schematics/655290/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/ladder-diagrams-electrical-control-logic-schematics/655290.png","ImageObject",300,407,{"name":92,"@type":93},"\tCallum ","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-31","2026-10-25",true,{"@type":102,"interactionType":103,"userInteractionCount":29},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"Why do ladder diagrams use the names L1 and L2 for power poles?","Question",{"text":112,"@type":113},"L1 designates the hot AC conductor, while L2 designates the neutral/grounded conductor, and the labels are used to clarify which side of the power supply is grounded for correct operation.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"What is the purpose of wire numbers in ladder logic systems?",{"text":117,"@type":113},"Permanently connected, electrically common points must share the same label, and wire numbers stay the same across junctions or nodes to simplify assembly and maintenance.",{"name":119,"@type":110,"acceptedAnswer":120},"How does the document explain safer fuse placement regarding ground faults?",{"text":121,"@type":113},"Placing the load(s) nearest the grounded power conductor ensures that an accidental grounding will tend to short the load and blow the fuse rather than unintentionally energizing lamps, relays, or solenoids.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},655290,1793051838,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":29,"category_name":30,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":29,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":21,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":143,"read_time":144},137451211410,"https://ap-avatar.wpscdn.com/avatar/2000bb0a9246f588df?x-image-process=image/resize,m_fixed,w_180,h_180&k=1786362646172706240","\"Ladder\" diagrams  \nLadder diagrams are specialized schematics commonly used to document industrial control logic systems. They are called \"ladder\" diagrams because they resemble a ladder, with two vertical rails (supply power) and as many\"rungs\" (horizontal lines) as there are control circuits to represent. If we wanted to draw a simple ladder diagram showing a lamp that is controlled by a hand switch, it would look like this:  \nThe \"L 1 \" and \"L2 \" designations refer to the two poles of a 120 VAC supply, unless otherwise noted. L1 is the \"hot\"conductor, and L2 is the grounded (\"neutral\") conductor. These designations have nothing to do with inductors, just to make things confusing. The actual transformer or generator supplying power to this circuit is omitted for simplicity. In reality, the circuit looks something like this:  \nTypically in industrial relay logic circuits, but not always, the operating voltage for the switch contacts and relay coils will be 120 volts AC. Lower voltage AC and even DC systems are sometimes built and documented according to\"ladder\" diagrams:  \nSo long as the switch contacts and relay coils are all adequately rated, it really doesn't matter what level of voltage is chosen for the system to operate with.  \nNote the number \"1\" on the wire between the switch and the lamp. In the real world, that wire would be labeled with that number, using heat-shrink or adhesive tags, wherever it was convenient to identify. Wires leading to the switch would be labeled \"L 1 \" and \"1,\" respectively. Wires leading to the lamp would be labeled \"1\" and \"L2,\"respectively. These wire numbers make assembly and maintenance very easy. Each conductor has its own unique wire number for the control system that it's used in. Wire numbers do not change at any junction or node, even if  \nwire size, color, or length changes going into or out of a connection point. Of course, it is preferable to maintain consistent wire colors, but this is not always practical. What matters is that any one, electrically continuous point ina control circuit possesses the same wire number. Take this circuit section, for example, with wire \\#25 as a single, electrically continuous point threading to many different devices:  \nIn ladder diagrams, the load device (lamp, relay coil, solenoid coil, etc.) is almost always drawn at the right-hand side of the rung. While it doesn't matter electrically where the relay coil is located within the rung, it does matter which end of the ladder's power supply is grounded, for reliable operation.  \nTake for instance this circuit:  \nHere, the lamp (load) is located on the right-hand side of the rung, and so is the ground connection for the power source. This is no accident or coincidence; rather, it is a purposeful element of good design practice. Suppose that wire \\#1 were to accidently come in contact with ground, the insulation of that wire having been rubbed off so that the bare conductor came in contact with grounded, metal conduit. Our circuit would now function like this:  \nWith both sides of the lamp connected to ground, the lamp will be \"shorted out\" and unable to receive power to light up. If the switch were to close, there would be a short-circuit, immediately blowing the fuse.  \nHowever, consider what would happen to the circuit with the same fault (wire \\#1 coming in contact with ground), except this time we'll swap the positions of switch and fuse (L2 is still grounded):  \nThis time the accidental grounding of wire \\#1 will force power to the lamp while the switch will have no effect. It is much safer to have a system that blows a fuse in the event of a ground fault than to have a system that uncontrollably energizes lamps, relays, or solenoids in the event of the same fault. For this reason, the load(s) must always be located nearest the grounded power conductor in the ladder diagram.  \n• REVIEW:  \n• Ladder diagrams (sometimes called \"ladder logic\") are a type of electrical notation and symbology freque","cbCaifycqjR0K7MA","https://ap.wps.com/l/cbCaifycqjR0K7MA","pdf",1959962,"English","# Ladder diagrams basics\n## Rails, rungs, and L1/L2\n## Wire numbering and continuity\n## Grounding and fault safety\n# Digital logic functions\n## OR logic with parallel contacts\n## AND logic with series contacts\n## NOT logic with normally-closed contacts","[{\"question\":\"Why do ladder diagrams use the names L1 and L2 for power poles?\",\"answer\":\"L1 designates the hot AC conductor, while L2 designates the neutral/grounded conductor, and the labels are used to clarify which side of the power supply is grounded for correct operation.\"},{\"question\":\"What is the purpose of wire numbers in ladder logic systems?\",\"answer\":\"Permanently connected, electrically common points must share the same label, and wire numbers stay the same across junctions or nodes to simplify assembly and maintenance.\"},{\"question\":\"How does the document explain safer fuse placement regarding ground faults?\",\"answer\":\"Placing the load(s) nearest the grounded power conductor ensures that an accidental grounding will tend to short the load and blow the fuse rather than unintentionally energizing lamps, relays, or solenoids.\"}]","Ladder diagrams - Electrical control logic schematics | PDF",1792960610,176]