[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-1-en-105":3,"doc-seo-561296-105":53,"doc-detail-561296-en":127},{"code":4,"msg":5,"data":6},0,"success",[7,14,19,24,29,34,39,44,49],{"id":8,"doc_module":9,"doc_module_name":10,"category_name":11,"show_sort_weight":12,"slug":13},11,1,"Template","Presentations",90,"presentations",{"id":15,"doc_module":9,"doc_module_name":10,"category_name":16,"show_sort_weight":17,"slug":18},12,"Resumes",80,"resumes",{"id":20,"doc_module":9,"doc_module_name":10,"category_name":21,"show_sort_weight":22,"slug":23},14,"Invoices",70,"invoices",{"id":25,"doc_module":9,"doc_module_name":10,"category_name":26,"show_sort_weight":27,"slug":28},15,"Posters",60,"posters",{"id":30,"doc_module":9,"doc_module_name":10,"category_name":31,"show_sort_weight":32,"slug":33},16,"Social Media",50,"social-media",{"id":35,"doc_module":9,"doc_module_name":10,"category_name":36,"show_sort_weight":37,"slug":38},17,"Forms",40,"forms",{"id":40,"doc_module":9,"doc_module_name":10,"category_name":41,"show_sort_weight":42,"slug":43},18,"Letters",30,"letters",{"id":45,"doc_module":9,"doc_module_name":10,"category_name":46,"show_sort_weight":47,"slug":48},21,"Paper Templates",5,"papers-templates",{"id":50,"doc_module":9,"doc_module_name":10,"category_name":51,"show_sort_weight":4,"slug":52},158,"General","general-158",{"code":4,"msg":54,"data":55},"ok",{"site_id":56,"language":57,"slug":58,"title":59,"keywords":60,"description":61,"schema_data":62,"social_meta":120,"head_meta":122,"extra_data":124,"updated_unix":126},105,"en","cable-carrying-capacity-wire-fill-40-of-the-cross-sectional-area-csa-uk-wiring-regulations-bs7671","Cable carrying capacity (wire fill) - 40% of the cross sectional area (CSA) - UK Wiring regulations BS7671","","Technical datasheet providing guidance for selecting the nominal diameter of flexible non-metallic and metallic conduit systems based on cable carrying capacity (wire fill). It applies UK Wiring Regulations BS7671, recommending the combined cross sectional area of the installed cables not exceed 40% of the conduit’s cross sectional area when using 3 or more cables. Step-by-step instructions use a Cross Sectional Area (CSA) chart, sum total CSA, and reference 40% conduit fill tables. Includes worked examples and tabulated wire fill values.",{"@graph":63,"@context":119},[64,80,102],{"@type":65,"itemListElement":66},"BreadcrumbList",[67,71,74,77],{"item":68,"name":69,"@type":70,"position":9},"https://docshare.wps.com","Home","ListItem",{"item":72,"name":10,"@type":70,"position":73},"https://docshare.wps.com/template/",2,{"item":75,"name":51,"@type":70,"position":76},"https://docshare.wps.com/template/general/",3,{"item":78,"name":59,"@type":70,"position":79},"https://docshare.wps.com/template/cable-carrying-capacity-wire-fill-40-of-the-cross-sectional-area-csa-uk-wiring-regulations-bs7671/561296/",4,{"url":78,"name":59,"@type":81,"image":82,"author":87,"headline":59,"publisher":90,"fileFormat":93,"inLanguage":57,"description":61,"dateModified":94,"datePublished":95,"encodingFormat":93,"isAccessibleForFree":96,"interactionStatistic":97},"DigitalDocument",{"url":83,"@type":84,"width":85,"height":86},"https://docshare.wps.com/thumbnails/cable-carrying-capacity-wire-fill-40-of-the-cross-sectional-area-csa-uk-wiring-regulations-bs7671/561296.png","ImageObject",442,249,{"name":88,"@type":89},"kopisore","Person",{"url":68,"name":91,"@type":92},"DocShare","Organization","application/pdf","2026-10-30","2026-10-12",true,{"@type":98,"interactionType":99,"userInteractionCount":101},"InteractionCounter",{"@type":100},"ViewAction",7,{"@type":103,"mainEntity":104},"FAQPage",[105,111,115],{"name":106,"@type":107,"acceptedAnswer":108},"How is the 40% cable fill limit determined under BS7671?","Question",{"text":109,"@type":110},"Add the cross sectional areas (CSA) of all individual cables and ensure the combined CSA does not exceed 40% of the conduit’s cross sectional area when using 3 or more cables.","Answer",{"name":112,"@type":107,"acceptedAnswer":113},"What steps are used to select the nominal diameter of a conduit?",{"text":114,"@type":110},"First, establish the number and size of each wire. Next, look up each wire’s CSA in the CSA chart and sum to get Total CSA. Then, choose a conduit whose 40% fill value is higher than the Total CSA.",{"name":116,"@type":107,"acceptedAnswer":117},"What do Table 1 and Table 2 provide?",{"text":118,"@type":110},"Table 1 lists each wire size’s cross sectional area (CSA) used for calculating Total CSA. Table 2 lists conduit nominal diameters with 100% and 40% fill values used to select an appropriate conduit size.","https://schema.org",{"og:url":78,"og:type":121,"og:title":59,"og:site_name":91,"og:description":61},"article",{"robots":123,"canonical":78},"index,follow",{"doc_id":125,"site_id":56},561296,1792086995,{"code":4,"msg":5,"data":128},{"doc_id":125,"user_id":129,"nickname":88,"user_avatar":130,"doc_module":9,"category_id":50,"category_name":51,"doc_title":59,"doc_description":61,"doc_content":131,"file_id":132,"file_url":133,"file_type":134,"file_size":135,"view_count":101,"is_deleted":4,"is_public":9,"is_downloadable":9,"audit_status":9,"page_count":73,"language":136,"language_code":57,"site_id":56,"html_lang":57,"table_of_contents":137,"faqs":138,"seo_title":139,"seo_description":61,"update_tm":140,"read_time":9},962090880963,"https://ap-avatar.wpscdn.com/davatar_6f874abed73319feea01a86fa6f0fab8","—  \nTECHNICA L DATA SHEET  \nFlexible non-metallic conduit systems  \nCable carrying capacity (wire fill)  \n40% of the cross sectional area (CSA) -UK Wiring regulations BS7671 recommend that the total cross sectional area of the sum of individual cables shall not exceed 40% of the cross sectional area of the conduit based on 'using 3 or more cables'.  \nThese instructions enable you to select the correct nominal diameter of non-metallic conduit, depending on the number and overall diameter of the cables to protect.  \nInstructions to define the nominal diameter of a non-metallic conduit:  \n• Step 1: Establish the number and size of each wire to be run in the conduit  \n• Step 2: Look on the Cross Sectional Area (CSA) chart (table 1), look up the CSA taken up by each of the wires from Step 1  \n• Step 3: Add all the CSA values together (Total CSA)  \n• Step 4: Look on the conduit fill value chart (table 2) and choose a conduit with a 40% fill value higher than the total CSA from Step 3  \n—  \nTable 1-Cross Sectional Area (CSA) chart  \n\n| Cross sectional area (CSA)[mm2] | Overall Diameter [mm] | CSA [mm2] |\n| --- | --- | --- |\n\n1 0.79  \n\n| 1.5 | 1.77 |\n| --- | --- |\n| 2.5 | 4.91 |\n\n4 12.57  6 28.27  10 78.54  16 201.06  25 490.87  35 962.11 50 1963.50  \nExample-What size of conduit to use?  \n• Step 1: 4 x 2.5mm cables, 2 x 10mm cables, and 3 x 25mm cables  \n• Step 2:  \n- The CSA of Four 2. 5mm cables is 19.64 (4 x 4 . 91)  \n- The CSA of Two 10mm cables is 157.08 (2 x 78 . 54)  \n- The CSA of Three 25mm cables is 1472.61 (3 x 490.87)  \n• Step 3: Total of these groups is  \n19.64 + 402.12 + 1472.61 = 1649.33  \n• Step 4: Using Table 2, we chose the size of non-metallic conduit with 40% fill value higher than 1649. 33: 106mm  \nNOTE: The information given above relates to PA-Standard weight conduit and Adaptalok fittings. It is given in good faith and should be used only asa guide in conjunction with the relevant wiring regulations.  \n—  \nTable 2-Wire fill of non-metallic conduit  \n\n| Nominal diameter (mm) | 100%\u003Cbr>fill value | 40%\u003Cbr>fill value |\n| --- | --- | --- |\n| 10 | 33.2 | 13 |\n| 13 | 72.4 | 29 |\n| 16 | 109.4 | 44 |\n| 18 | 158.4 | 63 |\n| 21 | 213.8 | 86 |\n| 28 | 369.8 | 148 |\n| 34 | 602.6 | 241 |\n| 42 | 973.1 | 390 |\n| 54 | 1698.2 | 680 |\n| 80 | 3520 | 1410 |\n| 106 | 6500 | 2600 |\n\n—  \nTECHNICA L DATA SHEET  \nFlexible metallic conduit systems  \nCable carrying capacity (wire fill)  \n40% of the cross sectional area (CSA) -UK Wiring regulations BS7671 recommend that the total cross sectional area of the sum of individual cables shall not exceed 40% of the cross sectional area of the conduit based on 'using 3 or more cables'.  \nThese instructions enable you to select the correct nominal diameter of metallic conduit, depending on the number and overall diameter of the cables to protect.  \nInstructions to define the nominal diameter of a metallic conduit:  \n• Step 1: Establish the number and size of each wire to be run in the conduit  \n• Step 2: Look on the Cross Sectional Area (CSA) chart (table 1), look up the CSA taken up by each of the wires from Step 1  \n• Step 3: Add all the CSA values together (Total CSA)  \n• Step 4: Look on the conduit fill value chart (table 2) and choose a conduit with a 40% fill value higher than the total CSA from Step 3  \n—  \nTable 1-Cross Sectional Area (CSA) chart  \n\n| Cross sectional area (CSA)[mm2] | Overall Diameter [mm] | CSA [mm2] |\n| --- | --- | --- |\n\n1 0.79  \n\n| 1.5 | 1.77 |\n| --- | --- |\n| 2.5 | 4.91 |\n\n4 12.57  6 28.27  10 78.54  16 201.06  25 490.87  35 962.11 50 1963.50  \nExample-What size of conduit to use?  \n• Step 1: 4 x 2.5mm cables, 3 x 10mm cables, and 6 x 6mm cables  \n• Step 2:  \n- The CSA of Four 2. 5mm cables is 19.64 (4 x 4 . 91)  \n- The CSA of Three 10mm cables is 235.62 (3 x 78.54)  \n- The CSA of Six 6mm cables is 169.62 (6 x 28 . 27)  \n• Step 3: Total of these groups is  \n19.64 + 235.62 + 169.62 = 424.88  \n• Step 4: Using Table 2, we chose the size of metallic conduit with 40% fill va","cbCailezs5mVQI5y","https://ap.wps.com/l/cbCailezs5mVQI5y","pdf",116264,"English","# Cable carrying capacity guidance\n## 40% CSA basis (BS7671)\n## Selecting nominal conduit diameter\n## CSA chart (Table 1)\n## Conduit fill chart (Table 2)\n## Worked examples and notes","[{\"question\":\"How is the 40% cable fill limit determined under BS7671?\",\"answer\":\"Add the cross sectional areas (CSA) of all individual cables and ensure the combined CSA does not exceed 40% of the conduit’s cross sectional area when using 3 or more cables.\"},{\"question\":\"What steps are used to select the nominal diameter of a conduit?\",\"answer\":\"First, establish the number and size of each wire. Next, look up each wire’s CSA in the CSA chart and sum to get Total CSA. Then, choose a conduit whose 40% fill value is higher than the Total CSA.\"},{\"question\":\"What do Table 1 and Table 2 provide?\",\"answer\":\"Table 1 lists each wire size’s cross sectional area (CSA) used for calculating Total CSA. Table 2 lists conduit nominal diameters with 100% and 40% fill values used to select an appropriate conduit size.\"}]","Cable carrying capacity (wire fill) - 40% of the cross sectional area (CSA) - UK Wiring regulations BS7671 | PDF",1791805499]