{"id":3908,"date":"2020-04-12T19:02:15","date_gmt":"2020-04-12T16:02:15","guid":{"rendered":"http:\/\/www.benga.pro\/?p=3908"},"modified":"2026-03-08T10:20:59","modified_gmt":"2026-03-08T07:20:59","slug":"yangin-kablosu-kesit-hesabi","status":"publish","type":"post","link":"https:\/\/benga.pro\/index.php\/2020\/04\/12\/yangin-kablosu-kesit-hesabi\/","title":{"rendered":"Yang\u0131n kablosu kesit hesab\u0131"},"content":{"rendered":"<p>Binalarda yang\u0131n s\u0131ras\u0131nda baz\u0131 elektrikli ekipmanlar\u0131n en az\u0131ndan belli bir s\u00fcre boyunca \u00e7al\u0131\u015fmas\u0131n\u0131n sa\u011flanmas\u0131 gerekmektedir. Mesela binada yang\u0131n s\u00f6nd\u00fcrme sistemi pompalar\u0131 varsa, bu pompalar\u0131n yang\u0131na dayan\u0131kl\u0131 kablolarla beslenmesi gereklidir ki yang\u0131n esnas\u0131nda \u00e7al\u0131\u015fabilsin ve yang\u0131n\u0131n s\u00f6nd\u00fcr\u00fclmesine katk\u0131da bulunabilsin. E\u011fer bu pompalar normal kablolar ile beslenirse, yang\u0131n an\u0131nda 900\u00baC s\u0131cakl\u0131k mertebelerinde \u0131s\u0131ya maruz kal\u0131p \u00e7abucak yanacak ve yang\u0131n pompalar\u0131 \u00e7al\u0131\u015famayacakt\u0131r.<\/p>\n<p>Daha \u00f6nceki\u00a0 <strong>-&#8220;Yanmaz&#8221; Kablo&#8221;-\u00a0<\/strong> \u00a0ba\u015fl\u0131kl\u0131 yaz\u0131m\u0131zda, yang\u0131na dayan\u0131kl\u0131 kablolar hakk\u0131ndaki standartlar\u0131 incelemi\u015ftik. Yang\u0131n esnas\u0131nda b\u00fct\u00fcnl\u00fc\u011f\u00fcn\u00fc kaybetmemesi gereken ve ba\u011fl\u0131 oldu\u011fu ekipman\u0131 beslemeye devam etmesi gereken kablolar\u0131 esas alan\u00a0\u00a0<strong>IEC 60331-21,\u00a0<\/strong><strong>EN 50200 ve\u00a0<\/strong><strong>DIN 4102-12\u00a0<\/strong>standartlar\u0131n\u0131n detaylar\u0131na bakm\u0131\u015ft\u0131k. Buna g\u00f6re IEC 60331-2&#8217;e g\u00f6re FE180 olan kablonun yan\u0131na EN5200&#8217;e g\u00f6re PH 15\/30\/60\/90\/120\u00a0 geliyor yada DIN4102-12 standard\u0131na g\u00f6re E30\/60\/90 gibi ifadeler geliyordu. Bu rakamlar, dakika cinsinden ilgili standartta belirlenen yanma testine dayand\u0131klar\u0131 anlam\u0131na geliyordu. <strong>-&#8220;Yanmaz&#8221; Kablo&#8221;-\u00a0<\/strong> \u00a0ba\u015fl\u0131kl\u0131 yaz\u0131m\u0131za <a href=\"https:\/\/mekanikelektriktesisat.com\/2019\/06\/03\/yanmaz-kablo\/\">buraya t\u0131klayarak<\/a> ula\u015fabilirsiniz.<\/p>\n<hr \/>\n<p>Bu yaz\u0131da, yang\u0131n esnas\u0131nda \u00e7al\u0131\u015fmas\u0131 gereken ekipmanlar i\u00e7in nas\u0131l kablo se\u00e7ilece\u011fini g\u00f6rece\u011fiz. Buradaki en \u00f6nemli fakt\u00f6r tabi ki s\u0131cakl\u0131kt\u0131r. Gerek kablonun iletkeninin gerekse k\u0131l\u0131f\u0131n\u0131n y\u00fcksek s\u0131cakl\u0131klara maruz kalmas\u0131 durumunda davran\u0131\u015flar\u0131 de\u011fi\u015fecektir. Haliyle hesaplamalarda bu de\u011fi\u015fimlerin g\u00f6z \u00f6n\u00fcne al\u0131nmas\u0131 ka\u00e7\u0131n\u0131lmazd\u0131r.<\/p>\n<h5>1. Yang\u0131n y\u00fck\u00fc ve yang\u0131n\u0131n s\u0131cakl\u0131\u011f\u0131<\/h5>\n<p>Her yan\u0131c\u0131 maddenin bir yang\u0131n potansiyeli vard\u0131r. Bu potansiyel, daha \u00f6nceden bildi\u011fimiz alt \u0131s\u0131l de\u011fere tekab\u00fcl eder. \u00d6rne\u011fin bildi\u011fimiz odunun alt \u0131s\u0131l de\u011feri 2500 kcal\/kg&#8217;d\u0131r. Yang\u0131n ile ilgili konularda daha \u00e7ok Joule birimi tercih edildi\u011finden odunun alt \u0131s\u0131l de\u011feri yakla\u015f\u0131k 10.000 kJ\/kg olur. Yani 1kg odun yand\u0131\u011f\u0131nda a\u00e7\u0131\u011fa 10.000kJ kar\u015f\u0131l\u0131\u011f\u0131 \u0131s\u0131 \u00e7\u0131kar. 100kg odun yand\u0131\u011f\u0131nda ise a\u00e7\u0131\u011fa 1.000.000kJ = 1000MJ \u00e7\u0131kar.<\/p>\n<p>\u015eimdi, g\u00f6z\u00fcm\u00fcz\u00fcn \u00f6n\u00fcne herhangi bir mahal getirelim, mesela oturma odam\u0131z. Mobilyalar var, tekstil malzemeleri var, vs. (Bu malzemelerin kabaca hepsinin alt \u0131s\u0131l de\u011ferinin 10MJ\/kg oldu\u011funu kabul etsek \u00e7ok yan\u0131lmay\u0131z.) Odam\u0131z\u0131n i\u00e7inde a\u015fa\u011f\u0131 yukar\u0131 300kg malzeme olsa, odam\u0131z\u0131n yang\u0131n potansiyeli\u00a0 300kg x 10MJ\/kg =3000MJ olur.<\/p>\n<p>Oturma odam\u0131z\u0131n alan\u0131 da 20m2 olsun. Bu durumda odam\u0131z\u0131n yang\u0131n y\u00fck\u00fc,<\/p>\n<p>3000MJ\/ 20m2 = 150MJ\/m2 olur.<\/p>\n<p>\u0130\u015flemden de anla\u015f\u0131laca\u011f\u0131 \u00fczere yang\u0131n y\u00fck\u00fc birim alana d\u00fc\u015fen yang\u0131n potansiyelidir. Yang\u0131n y\u00fck\u00fc i\u00e7in belli bir de\u011fer vermek olduk\u00e7a g\u00fc\u00e7t\u00fcr. \u00c7\u00fcnk\u00fc bu de\u011fer ilgili mahalin i\u00e7indeki yan\u0131c\u0131 e\u015fyalar\u0131n say\u0131s\u0131yla, malzeme yap\u0131s\u0131yla de\u011fi\u015fir.\u00a0 Buna ra\u011fmen EN-1991-1-2 standard\u0131nda a\u015fa\u011f\u0131daki ortalama yang\u0131n y\u00fckleri verilm,\u015f. G\u00f6r\u00fcn\u00fc\u015fe g\u00f6re, bizim yukar\u0131da yapt\u0131\u011f\u0131m\u0131z oturma odas\u0131 \u00f6rne\u011fimizde 150MJ\/m2 de\u011feri konutlar i\u00e7in verilen 780MJ\/m2 de\u011ferinin yan\u0131nda epey k\u00fc\u00e7\u00fck kalm\u0131\u015f.<\/p>\n<table style=\"height: 329px;\" width=\"386\">\n<tbody>\n<tr>\n<td width=\"128\"><strong>Mahal<\/strong><\/td>\n<td width=\"89\"><strong>Yang\u0131n Y\u00fck\u00fc<\/strong><\/td>\n<\/tr>\n<tr>\n<td>Konutlar<\/td>\n<td>780 MJ\/m2<\/td>\n<\/tr>\n<tr>\n<td>Hastane (Oda)<\/td>\n<td>230 MJ\/m2<\/td>\n<\/tr>\n<tr>\n<td>Otel (Oda)<\/td>\n<td>310 MJ\/m2<\/td>\n<\/tr>\n<tr>\n<td>K\u00fct\u00fcphane<\/td>\n<td>1500 MJ\/m2<\/td>\n<\/tr>\n<tr>\n<td>Ofis<\/td>\n<td>420 MJ\/m2<\/td>\n<\/tr>\n<tr>\n<td>Okul S\u0131n\u0131f\u0131<\/td>\n<td>285 MJ\/m2<\/td>\n<\/tr>\n<tr>\n<td>Al\u0131\u015fveri\u015f Merkezi<\/td>\n<td>600 MJ\/m2<\/td>\n<\/tr>\n<tr>\n<td>Sinema<\/td>\n<td>300 MJ\/m2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Yang\u0131n y\u00fck\u00fc ile do\u011fru orant\u0131l\u0131 olarak \u0131s\u0131 enerjisi ortaya \u00e7\u0131kacakt\u0131r. \u00c7\u0131kan bu \u0131s\u0131 yang\u0131n\u0131n s\u0131cakl\u0131\u011f\u0131n\u0131 o denli artt\u0131racakt\u0131r.\u00a0 Standart bir yang\u0131nda (Sel\u00fclozik bazl\u0131 yan\u0131c\u0131 madde yang\u0131n\u0131), yang\u0131n ba\u015flad\u0131\u011f\u0131nda ilk dakikalarda s\u0131cakl\u0131k \u00e7ok h\u0131zl\u0131 artar. \u0130lk 5 dakikada s\u0131cakl\u0131k yakla\u015f\u0131k 500 \u00baC olur, 10 dakika sonra yakla\u015f\u0131k 600 \u00baC, 15 dakika sonra yakla\u015f\u0131k 700 \u00baC ve 30 dakika sonra yakla\u015f\u0131k 800 \u00baC\u2019ye \u00e7\u0131kar. S\u0131cakl\u0131k 90 dakika sonra yakla\u015f\u0131k 1000 \u00baC ve \u00fc\u00e7 saat sonra yakla\u015f\u0131k 1100 \u00baC\u2019ye ula\u015f\u0131r. Tamamen kapal\u0131 mahallerde olu\u015fan yang\u0131nlarda, 400 \u00baC civar\u0131ndaki bir s\u0131cakl\u0131ktan sonra oksijen azald\u0131\u011f\u0131nda yanma yava\u015flar ve s\u0131cakl\u0131k d\u00fc\u015fmeye ba\u015flar. Mahalin bir taraf\u0131 a\u00e7\u0131ld\u0131\u011f\u0131nda mahale oksijenin girmesiyle yang\u0131n tekrardan canlan\u0131r ve s\u0131cakl\u0131k artmaya ba\u015flar.<\/p>\n<p>Standart bir yang\u0131nda, EN-1991-1-2 standard\u0131nda tan\u0131mlanan a\u015fa\u011f\u0131daki ba\u011f\u0131nt\u0131 ile s\u0131cakl\u0131k ve zaman ili\u015fkisini bulmak m\u00fcmk\u00fcnd\u00fcr.\u00a0 \u00a0(Hidrokarbon yang\u0131nlar\u0131 gibi di\u011fer t\u00fcr yang\u0131nlar i\u00e7in ba\u011f\u0131nt\u0131 farkl\u0131d\u0131r ama konuyu \u00e7ok da\u011f\u0131tmamak ad\u0131na burada de\u011finilmeyecektir. \u0130lgilenenler EN-1991-1-2 numaral\u0131 standarda ba\u015fvurabilirler.)<\/p>\n<p><strong>T = 20 +345 log (8t+1)<\/strong><\/p>\n<p>T: S\u0131cakl\u0131k (\u00baC)<\/p>\n<p>t: Zaman (Dakika)<\/p>\n<p style=\"text-align: left;\">A\u015fa\u011f\u0131daki excel tablosunda t de\u011ferini girerek, o kadar s\u00fcre sonra olu\u015facak s\u0131cakl\u0131k de\u011ferini bulabilirsiniz. Ayr\u0131ca s\u00fcre-s\u0131cakl\u0131k grafi\u011fini de g\u00f6rebilirsiniz.<\/p>\n<p style=\"text-align: center;\"><iframe loading=\"lazy\" src=\"https:\/\/onedrive.live.com\/embed?resid=5E384BA25F057C18%21131&amp;authkey=%21AMRuTYxP_4mf9NQ&amp;em=2&amp;wdAllowInteractivity=False&amp;AllowTyping=True&amp;Item='Sayfa1'!A2%3AF20&amp;wdHideGridlines=True&amp;wdDownloadButton=True&amp;wdInConfigurator=True\" width=\"469\" height=\"397\" frameborder=\"0\" scrolling=\"no\"><\/iframe><\/p>\n<p style=\"text-align: left;\">Yang\u0131n s\u0131ras\u0131nda \u00e7al\u0131\u015fmas\u0131na devam etmesini istedi\u011fimiz kablo, alevlerin i\u00e7inde \u00e7ok y\u00fcksek s\u0131cakl\u0131klara maruz kalacakt\u0131r. Yukar\u0131daki ba\u011f\u0131nt\u0131dan da g\u00f6r\u00fcld\u00fc\u011f\u00fc gibi s\u0131cakl\u0131k 900-1000\u00baC s\u0131cakl\u0131klara \u00e7\u0131kmaktad\u0131r.<\/p>\n<p>Bu kadar \u015feyi anlatmam\u0131z\u0131n temel sebebine gelirsek: Kablonun iletkeni bu kadar s\u0131cakl\u0131k alt\u0131nda nas\u0131l davranacak? Kablomuz 1000\u00baC s\u0131cakl\u0131\u011f\u0131nda bir yang\u0131n\u0131n i\u00e7inde olacak ama kablonun yang\u0131na dayan\u0131kl\u0131 \u00f6zel k\u0131l\u0131f\u0131n\u0131n i\u00e7indeki iletkenin s\u0131cakl\u0131\u011f\u0131n\u0131n yang\u0131n s\u0131cakl\u0131\u011f\u0131na ula\u015fmas\u0131 hemen olmaz, ara\u015ft\u0131rmalar bunun ortalama 30 dakika kadar zaman ald\u0131\u011f\u0131 ifade etmektedir.<\/p>\n<h5>2. S\u0131cakl\u0131\u011fa g\u00f6re iletken direncinin hesaplanmas\u0131<\/h5>\n<p>Artan s\u0131cakl\u0131kla birlikte kablonun i\u00e7indeki iletkenin de direnci artacakt\u0131r. \u0130letkenin yeni direnci \u015fu \u015fekilde bulunur:<\/p>\n<p>Bir iletkenin T<sub>1<\/sub>\u00a0s\u0131cakl\u0131\u011f\u0131ndaki direnci R<sub>1<\/sub>\u00a0olsun, s\u0131cakl\u0131k biraz daha art\u0131p T<sub>2\u00a0<\/sub>s\u0131cakl\u0131\u011f\u0131na geldi\u011finde iletkenin direnci R<sub>2<\/sub>\u00a0olacakt\u0131r.<\/p>\n<p>Buna g\u00f6re direncin s\u0131cakl\u0131kla de\u011fi\u015fimi a\u015fa\u011f\u0131daki denkleme g\u00f6re ger\u00e7ekle\u015fir<\/p>\n<p>(R<sub>2<\/sub>\u00a0\u2013 R<sub>1<\/sub>) \/ R<sub>1<\/sub>\u00a0= \u03b1 (T<sub>2<\/sub>\u00a0\u2013 T<sub>1<\/sub>) \u00a0veya<\/p>\n<p><strong>R<sub>2<\/sub>\u00a0= R<sub>1\u00a0<\/sub>x [1 + \u03b1 (T<sub>2<\/sub>\u00a0\u2013 T<sub>1<\/sub>) ]<\/strong><\/p>\n<p>\u03b1 iletkenin direncinin s\u0131cakl\u0131\u011fa g\u00f6re de\u011fi\u015fim katsay\u0131s\u0131d\u0131r. Her maddenin kendine \u00f6zg\u00fc bir de\u011fi\u015fim katsay\u0131s\u0131 bulunur. Bak\u0131r iletkenlerde\u00a0 \u03b1 =0,00393, al\u00fcminyum iletkenlerde \u03b1=0,00403 al\u0131n\u0131r.<\/p>\n<p>\u00d6rne\u011fin 20\u00baC de 1,83 Ohm\/km olarak verilen 10mm2 kesitli bak\u0131r iletkenin 70\u00b0C s\u0131cakl\u0131ktaki direnci<\/p>\n<p>R<sub>2<\/sub>\u00a0= 1,83<sub>\u00a0<\/sub>x [1 + 0,00393 (70\u00baC \u2013 20\u00baC) ]<\/p>\n<p>R<sub>2<\/sub>\u00a0= 2,19 Ohm\/km<\/p>\n<p>olacakt\u0131r.<\/p>\n<p>Ama bu form\u00fcl\u00fcm\u00fcz y\u00fcksek s\u0131cakl\u0131klar daha do\u011frusu 200\u00baC s\u0131cakl\u0131\u011f\u0131n \u00fczerindeki s\u0131cakl\u0131klarda\u00a0 s\u00f6z konusu oldu\u011funda farkl\u0131 bir hal almaktad\u0131r.<\/p>\n<p><strong>R<sub>2<\/sub>\u00a0= R<sub>1\u00a0<\/sub>x [1 + \u03b1 (T<sub>2<\/sub>\u00a0\u2013 T<sub>1<\/sub>) + \u03b2 (T<sub>2<\/sub>\u00a0\u2013 T<sub>1<\/sub>)<sup>2<\/sup>]<\/strong><\/p>\n<p>Bu ba\u011f\u0131nt\u0131da bak\u0131r i\u00e7in \u03b2=6&#215;10<sup>-7 <\/sup>K<sup>2<\/sup>\u00a0&#8216;dir.<\/p>\n<p>Yukar\u0131daki \u00f6rne\u011fimizdeki iletkenin 500\u00baC deki s\u0131cakl\u0131\u011f\u0131n\u0131 bulal\u0131m:<\/p>\n<p>R<sub>2<\/sub>\u00a0= 1,83<sub>\u00a0<\/sub>x [1 + 0,00393 (500\u00baC \u2013 20\u00baC) + 0,0000006 (500\u00baC \u2013 20\u00baC)<sup>2<\/sup> \u00a0]<\/p>\n<p>R<sub>2<\/sub>\u00a0= 5,53 Ohm\/km<\/p>\n<p>Alternatif olarak <strong>Wiedemann-Franz<\/strong> yasas\u0131ndan bak\u0131r iletken i\u00e7in t\u00fcretilen<\/p>\n<p><strong>R<sub>2<\/sub>\u00a0= R<sub>1\u00a0<\/sub>x [(T<sub>2<\/sub>\u00a0+ 273)\/\u00a0 (T<sub>1<\/sub>+273)]<sup>1,16<\/sup><\/strong><\/p>\n<p>ba\u011f\u0131nt\u0131s\u0131 da kullan\u0131labilir. Bu ba\u011f\u0131nt\u0131ya g\u00f6re yukar\u0131daki \u00f6rne\u011fimizi uygularsak<\/p>\n<p>R<sub>2<\/sub>\u00a0= 1,83<sub>\u00a0<\/sub>x [(500 +273) \/ (20 +273)]<sup>1,16<\/sup><\/p>\n<p>R<sub>2<\/sub>\u00a0= 5,63 Ohm\/km de\u011feri bulunur.<\/p>\n<p style=\"text-align: left;\">G\u00f6r\u00fcld\u00fc\u011f\u00fc gibi, y\u00fcksek s\u0131cakl\u0131klar alt\u0131nda iletkenin direnci ciddi oranda de\u011fi\u015fmektedir. Bu durumda yang\u0131n kablosu se\u00e7erken hesaplarda gerekti\u011fi yerlerde y\u00fcksek s\u0131cakl\u0131k direncini kullanmak gereklidir.<\/p>\n<p>Bak\u0131r iletkenler i\u00e7in, y\u00fckselen s\u0131cakl\u0131kla olu\u015facak diren\u00e7 de\u011ferini a\u015fa\u011f\u0131daki excel tablosunu kullanarak bulabilirsiniz.<\/p>\n<p style=\"text-align: center;\"><iframe loading=\"lazy\" src=\"https:\/\/onedrive.live.com\/embed?resid=5E384BA25F057C18%21131&amp;authkey=%21AMRuTYxP_4mf9NQ&amp;em=2&amp;wdAllowInteractivity=False&amp;AllowTyping=True&amp;Item='Sayfa2'!B1%3AF22&amp;wdHideGridlines=True&amp;wdDownloadButton=True&amp;wdInConfigurator=True\" width=\"457\" height=\"470\" frameborder=\"0\" scrolling=\"no\"><\/iframe><\/p>\n<h5>3. Ak\u0131m ta\u015f\u0131ma kapasitesi a\u00e7\u0131s\u0131ndan kontrol<\/h5>\n<p>Teknik f\u00f6ylerde kablolar\u0131n \u00a020\u00baC s\u0131cakl\u0131k i\u00e7in DC direnci ve belli ortamdaki(havada yada toprakta) iletken s\u0131cakl\u0131\u011f\u0131 azami 70\u00baC yada 90\u00baC olacak \u015fekilde\u00a0 ak\u0131m ta\u015f\u0131ma kapasitesi verilir. Konumuza giren kablolar FE180 t\u00fcr\u00fc kablolar oldu\u011fu i\u00e7in 90\u00baC iletken s\u0131cakl\u0131\u011f\u0131ndaki ak\u0131m ta\u015f\u0131ma kapasiteleri verilir.<\/p>\n<p>1.b\u00f6l\u00fcmde yang\u0131n s\u0131cakl\u0131\u011f\u0131n\u0131n \u00e7ok y\u00fcksek de\u011ferlere \u00e7\u0131kt\u0131\u011f\u0131n\u0131 ifade etmi\u015ftik. \u00d6yle ki bu s\u0131cakl\u0131klar bak\u0131r\u0131n, yani kablomuzun iletkeninin, ergime s\u0131cakl\u0131\u011f\u0131n\u0131n s\u0131n\u0131r\u0131na yakla\u015fmaktad\u0131r. Bak\u0131r\u0131n ergime s\u0131cakl\u0131\u011f\u0131 1085\u00baC&#8217;dir. (Bu arada al\u00fcminyumun ergime s\u0131cakl\u0131\u011f\u0131 660\u00baC&#8217;dir. San\u0131r\u0131m bu limit, al\u00fcminyumdan yang\u0131na dayan\u0131kl\u0131 kablo yap\u0131lmamas\u0131n\u0131n nedenini a\u00e7\u0131klamaktad\u0131r.)<\/p>\n<p>Yang\u0131nda 900-1000\u00baC mertebelerine maruz kalan kablonun bak\u0131r iletkenin \u00fczerinde, ilaveten y\u00fck ak\u0131m\u0131n\u0131n ortaya \u00e7\u0131karaca\u011f\u0131 s\u0131cakl\u0131k art\u0131\u015f\u0131 da olacakt\u0131r. Bu ilave art\u0131\u015f, bak\u0131r\u0131 ergime s\u0131cakl\u0131\u011f\u0131na eri\u015ftirecek kadar olmamal\u0131d\u0131r.<\/p>\n<p>Bu konudaki ara\u015ft\u0131rmamda 2 farkl\u0131 g\u00f6r\u00fc\u015fe rastlad\u0131m. Bunlardan ilki <strong>Prysmian<\/strong>&#8216;\u0131n \u201c<a href=\"http:\/\/www.benga.pro\/wp-content\/uploads\/2020\/04\/BS8519_2010.pdf\">SELECTION AND INSTALLATION OF FIRE-RESISTANT CABLES FOR LIFE SAFETY AND FIRE FIGHTING APPLICATIONS<\/a>\u201d isimli yay\u0131n\u0131nda yer alan g\u00f6r\u00fc\u015ft\u00fcr:<\/p>\n<p>Kataloglarda verilen ak\u0131m ta\u015f\u0131ma kapasitesi miktar\u0131nda ak\u0131m ta\u015f\u0131yan bir iletkenin, 950\u00baC iletken s\u0131cakl\u0131\u011f\u0131nda meydana getirece\u011fi s\u0131cakl\u0131k art\u0131\u015f\u0131, iletken s\u0131cakl\u0131\u011f\u0131 90\u00baC olan iletkende meydana gelen art\u0131\u015ftan daha fazla olacakt\u0131r. Bununla birlikte bu art\u0131\u015f, 50\u00baC den daha az olacakt\u0131r ve yang\u0131n\u0131n neden oldu\u011fu s\u0131cakl\u0131k art\u0131\u015f\u0131na g\u00f6re \u00f6nemli de\u011fildir.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-3939 aligncenter\" src=\"http:\/\/www.benga.pro\/wp-content\/uploads\/2020\/04\/BS6387-Fire-Performance-Standard-1-300x178-1.jpg\" alt=\"\" width=\"300\" height=\"178\" \/><\/p>\n<p>Di\u011fer ikinci g\u00f6r\u00fc\u015f ise <strong>AVRUPA BAKIR ENST\u0130T\u00dcS\u00dc&#8217;<\/strong>n\u00fcn yay\u0131nlad\u0131\u011f\u0131 <a href=\"http:\/\/www.benga.pro\/wp-content\/uploads\/2020\/04\/cu0109anfirecablesizingv3-190705125207.pdf\">&#8220;SELECTION AND SIZING OF CONDUCTORS SUPPLYING ELECTRICAL EQUIPMENT THAT MUST REMAIN FUNCTIONAL DURING FIRE&#8221;<\/a> isimli yay\u0131n\u0131nda yer alan g\u00f6r\u00fc\u015ft\u00fcr.<\/p>\n<p>Buna g\u00f6re, kablonun yang\u0131n esnas\u0131nda ortama verdi\u011fi \u0131s\u0131 g\u00fcc\u00fc(P<sub>H <\/sub>) yani yang\u0131na katk\u0131s\u0131, normal \u00e7al\u0131\u015fma \u015fartlar\u0131nda ortama yayd\u0131\u011f\u0131 \u0131s\u0131 g\u00fcc\u00fcne(P<sub>N <\/sub>) e\u015fit yada ondan k\u00fc\u00e7\u00fck olmal\u0131d\u0131r.<\/p>\n<p>IEC60287&#8217;ye g\u00f6re kablonun birim uzunluktaki kayb\u0131 Watt(W) cinsinden \u015f\u00f6yledir:\u00a0<strong> I<sup>2<\/sup>\u00a0. R<\/strong><\/p>\n<p><strong>P<sub>H<\/sub>=I<sub>H<\/sub><sup>2<\/sup>\u00a0. R<sub>H<\/sub>\u00a0\u2264 P<sub>N<\/sub>=I<sub>N<\/sub><sup>2<\/sup>\u00a0. R<sub>N<\/sub><\/strong><\/p>\n<p>P<sub>H\u00a0<\/sub>\u00a0 \u00a0 \u00a0 Yang\u0131n an\u0131nda kablonun birim uzunlu\u011funun ortama yayd\u0131\u011f\u0131 \u0131s\u0131 g\u00fcc\u00fc(W)<\/p>\n<p>I<sub>H<\/sub>.\u00a0 \u00a0 \u00a0 Yang\u0131n s\u0131cakl\u0131\u011f\u0131nda kablonun ak\u0131m ta\u015f\u0131ma kapasitesi(A)<\/p>\n<p>R<sub>H\u00a0 \u00a0 \u00a0 \u00a0\u00a0<\/sub>Yang\u0131n an\u0131nda iletken direnci (Ohm)<\/p>\n<p>P<sub>N\u00a0<\/sub>\u00a0 \u00a0 \u00a0Norma \u015fartlarda(@90\u00baC) kablonun birim uzunlu\u011funun ortama yayd\u0131\u011f\u0131 \u0131s\u0131 g\u00fcc\u00fc(W)<\/p>\n<p>I<sub>N<\/sub>\u00a0 \u00a0 \u00a0 \u00a0Normal \u015fartlarda(@90\u00baC) kablonun ak\u0131m ta\u015f\u0131ma kapasitesi(A)<\/p>\n<p>R<sub>N\u00a0 \u00a0 \u00a0 \u00a0\u00a0<\/sub>Normal \u015fartlarda(@90\u00baC) iletken direnci (Ohm)<\/p>\n<p style=\"text-align: left;\">I<sub>H<\/sub><sup>2<\/sup>\u00a0. R<sub>H<\/sub> \u2264 I<sub>N<\/sub><sup>2<\/sup>\u00a0. R<sub>N<\/sub><\/p>\n<p><strong>I<sub>H<\/sub> \u2264 I<sub>N<\/sub> \u221a (R<sub>N<\/sub>\u00a0\/ R<sub>H<\/sub>)<\/strong><\/p>\n<p>\u00d6rne\u011fin 1000\u00baC s\u0131cakl\u0131kta kablonun 10A ta\u015f\u0131mas\u0131 istenmektedir ve y\u00fck ak\u0131m\u0131na uygun olarak 16A sigorta se\u00e7ilmi\u015ftir. 3&#215;2,5mm2 kesitli kablonun uygunlu\u011funu kontrol edelim.<\/p>\n<p>2.5mm2 kesitli kablonun normal s\u0131cakl\u0131kta (90\u00baC) direnci<\/p>\n<p>R<sub>N<\/sub>\u00a0= 7,41<sub>\u00a0<\/sub>x [1 + 0,00393 (90\u00baC \u2013 20\u00baC) ]<\/p>\n<p>R<sub>N<\/sub>\u00a0= 9,45 Ohm\/km bulunur.<\/p>\n<p>2.5mm2 kesitli kablonun 1000\u00baC s\u0131cakl\u0131kta direnci Wiedemann-Franz yasas\u0131yla<\/p>\n<p>R<sub>H<\/sub>\u00a0= 7,41<sub>\u00a0<\/sub>x [(1000 +273) \/ (20 +273)]<sup>1,16<\/sup><\/p>\n<p>R<sub>H<\/sub>\u00a0= 40,72 Ohm\/km bulunur.<\/p>\n<p>Bu arada 3&#215;2.5mm2 kablonun 90\u00baC iletken s\u0131cakl\u0131\u011f\u0131nda ve 30\u00baC ortam s\u0131cakl\u0131\u011f\u0131nda ak\u0131m ta\u015f\u0131ma kapasitesi 32A dir.<\/p>\n<p>I<sub>H\u00a0<\/sub>\u2264 32<sub>\u00a0<\/sub>\u00a0 <strong>\u221a (<\/strong>9,45\/40,72)<\/p>\n<p>I<sub>H\u00a0<\/sub>\u2264 15,41 A<\/p>\n<p>sonucuna ula\u015f\u0131yoruz. Sigorta ak\u0131m\u0131m\u0131z 16A oldu\u011funa g\u00f6re ve 15,41&lt;16A oldu\u011fu i\u00e7in 2,5mm2 kablo uygun de\u011fildir. Ayn\u0131 hesab\u0131 \u015fimdi 4mm2 kablo i\u00e7in yapal\u0131m:<\/p>\n<p>R<sub>N<\/sub>\u00a0= 4,61<sub>\u00a0<\/sub>x [1 + 0,00393 (90\u00baC \u2013 20\u00baC) ] =5,87 Ohm\/km<\/p>\n<p>R<sub>H<\/sub>\u00a0= 4,61<sub>\u00a0<\/sub>x [(1000 +273) \/ (20 +273)]<sup>1,16<\/sup>\u00a0 = 25,33 Ohm\/km<\/p>\n<p>I<sub>H\u00a0<\/sub>\u2264 42<sub>\u00a0<\/sub>\u00a0 <strong>\u221a <\/strong>(5,87\/25,33)<\/p>\n<p>I<sub>H\u00a0<\/sub>\u2264 20,23 A<\/p>\n<p><sub>\u00a0<\/sub>4mm2 kesitli kablonun yang\u0131n \u015fartlar\u0131nda ak\u0131m ta\u015f\u0131ma kapasitesi olan 20,21A, sigorta anma de\u011feri 16A&#8217;den b\u00fcy\u00fckt\u00fcr.. Bu sebeple uygundur.<\/p>\n<p>Yukar\u0131da \u00f6rne\u011fini verdi\u011fimiz hesaplamalar\u0131 a\u015fa\u011f\u0131daki excel tablosunu kullanarak yapabilirsiniz.<\/p>\n<p style=\"text-align: center;\"><iframe loading=\"lazy\" src=\"https:\/\/onedrive.live.com\/embed?resid=5E384BA25F057C18%21131&amp;authkey=%21AMRuTYxP_4mf9NQ&amp;em=2&amp;wdAllowInteractivity=False&amp;AllowTyping=True&amp;Item='Sayfa2'!B26%3AF37&amp;wdHideGridlines=True&amp;wdDownloadButton=True&amp;wdInConfigurator=True\" width=\"457\" height=\"280\" frameborder=\"0\" scrolling=\"no\"><\/iframe><\/p>\n<h5>3. Devre Koruma<\/h5>\n<p>Yang\u0131n an\u0131nda \u00e7al\u0131\u015facak ekipman\u0131 besleyen devreyi koruman\u0131n esaslar\u0131 asl\u0131nda bilinen \u015fartlardan farkl\u0131 de\u011fildir. Bilindi\u011fi gibi, devre koruman\u0131n iletkeni korumak, canl\u0131lar\u0131 korumak ve ekipman\u0131 korumak ayaklar\u0131 vard\u0131r.<\/p>\n<p>Yang\u0131n an\u0131nda \u00e7al\u0131\u015facak ekipman\u0131 besleyen iletkenin korunmas\u0131 ile normal ekipman\u0131 besleyen ekipman\u0131n korunmas\u0131 anlay\u0131\u015f\u0131nda \u015fu fark vard\u0131r. Normal ko\u015fullarda, herhangi bir a\u015f\u0131r\u0131 ak\u0131m olu\u015ftu\u011funda kablo termal olarak zorlan\u0131p k\u0131l\u0131f\u0131 hasar g\u00f6rmeden, kablo hizmet \u00f6mr\u00fc etkilenmeden, standartlarda \u00f6ng\u00f6r\u00fclen s\u00fcre i\u00e7inde devre a\u00e7\u0131lmal\u0131d\u0131r. B\u00f6ylece kablonun bu a\u015f\u0131r\u0131 ak\u0131m hadisesinden sonra hizmetine devam etmesi beklenir. Ama yang\u0131n an\u0131nda hizmet veren kablolar\u0131n sadece o yang\u0131n an\u0131nda hizmet vermesi \u00f6nemlidir. Yang\u0131ndan sonras\u0131 i\u00e7in kablodan hizmet beklentisi olmaz. Zaten yukar\u0131daki b\u00f6l\u00fcmlerde anlat\u0131lanlar \u0131\u015f\u0131\u011f\u0131nda se\u00e7im yap\u0131lmas\u0131 durumunda kablonun b\u00fcy\u00fck kesitli olmas\u0131 ve bununda termal zorlanma a\u00e7\u0131s\u0131ndan avantaj sa\u011flamas\u0131 iletkenin korunmas\u0131nda fayda sa\u011flar.<\/p>\n<p>Yang\u0131n an\u0131nda \u00e7al\u0131\u015fmas\u0131 beklenen ekipman devrelerinde ka\u00e7ak ak\u0131m r\u00f6lesi (RCD) kullan\u0131lmaz. Y\u00fcksek s\u0131cakl\u0131klara maruz kalan kablo k\u0131l\u0131f\u0131n\u0131n iyonize olmas\u0131 neticesinde ka\u00e7ak ak\u0131mlar \u00e7o\u011fal\u0131r ve devre istenmeyen bir a\u00e7maya maruz kalabilir. Bu da ekipman\u0131n yang\u0131n an\u0131nda hizmet vermesini engeller. Bu nedenle yang\u0131n devrelerinde RCD kullan\u0131lmaz.<\/p>\n<p>Ancak dolayl\u0131 dokunmaya kar\u015f\u0131 korunma di\u011fer ekipmanlarda oldu\u011fu gibi yang\u0131n ekipmanlar\u0131nda da \u00f6nemlidir. \u00c7\u00fcnk\u00fc hata ak\u0131m\u0131 y\u00fcz\u00fcnden kurtarma ekiplerinin can g\u00fcvenli\u011fi tehlikeye girebilir. Hatta sair zamanda bu hata ak\u0131m\u0131 yang\u0131n sebebi bile olabilir. Dolayl\u0131 dokunmada hata ak\u0131m\u0131n\u0131n devre \u00fczerinde yeterince b\u00fcy\u00fck olup devre koruyucunun ani a\u00e7ma e\u015fi\u011finden y\u00fcksek olmas\u0131n\u0131n sa\u011flanmas\u0131 temel kurald\u0131r. Hata ak\u0131m\u0131n\u0131 ise t\u00fcm devrenin (trafodan yang\u0131n ekipman\u0131n\u0131n klemenslerine kadar olan devre) \u00e7evrim empedans\u0131na ba\u011fl\u0131d\u0131r. Yang\u0131n an\u0131nda y\u00fckselen s\u0131cakl\u0131k neticesinde \u00e7evrim empedans\u0131 artacakt\u0131r. Bu durumda beklenen hata ak\u0131m\u0131 azalacak ve devre kesicinin ani a\u00e7ma e\u015fi\u011finin alt\u0131nda kal\u0131rsa koruma yapamayacakt\u0131r.<\/p>\n<p>Bunu bir \u00f6rnek ile anlatmaya \u00e7al\u0131\u015fal\u0131m. Yang\u0131n an\u0131nda \u00e7al\u0131\u015facak ekipman\u0131n kablo boyu 40m olsun. Kablo 3x4mm2 kesitli ve C16A otomatik sigorta ile korunuyor olsun. Kablonun t\u00fcm boyu 1000\u00baC yang\u0131n i\u00e7inde kald\u0131\u011f\u0131n\u0131 varsayal\u0131m.<\/p>\n<p>C16A sigortadan \u00f6nceki devreyi burada detay girmemek ad\u0131na analiz etmeyelim. Bize sigorta \u00f6ncesi devrenin empedans\u0131 0,53Ohm olarak verilmi\u015f olsun.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-3929 aligncenter\" src=\"http:\/\/www.benga.pro\/wp-content\/uploads\/2020\/04\/cevrim-1-300x161.jpg\" alt=\"\" width=\"397\" height=\"213\" \/><\/p>\n<p>90\u00baC iletken s\u0131cakl\u0131\u011f\u0131nda 4mm2 kablonun direncini yukar\u0131daki \u00f6rneklerimizde 5,87mOhm\/m olarak bulmu\u015ftuk zaten. 40 faz iletkeni ve 40m PE iletkeni oldu\u011funu g\u00f6z\u00f6n\u00fcne al\u0131rsak bizim devremizin toplam direnci 0,47 Ohm olur. \u015eekle bakarsak C16A sigortadan \u00f6nceki devre de dahil toplam \u00e7evrim empedans\u0131 0,53+0,47=1 Ohm olmaktad\u0131r. Toplam hata ak\u0131m\u0131<\/p>\n<p>230V\/1Ohm =230A olur.<\/p>\n<p>C tipi sigorta ani a\u00e7ma e\u015fik de\u011feri anma ak\u0131m\u0131n\u0131n 10 kat\u0131d\u0131r. 16Ax10=160A C tipi sigortam\u0131z\u0131n ani a\u00e7ma de\u011feridir.<\/p>\n<p>230A&gt;160A oldu\u011fu i\u00e7in normal \u015fartlarda devremizde koruma ger\u00e7ekle\u015fmi\u015f olmaktad\u0131r.<\/p>\n<p>Yang\u0131n an\u0131nda 1000\u00baCde iletken direnci 25,33mOhm\/m oldu\u011funu yukar\u0131daki \u00f6rneklerde bulmu\u015ftuk. 40 faz iletkeni ve 40m PE iletkeni oldu\u011funu g\u00f6z \u00f6n\u00fcne al\u0131rsak bizim devremizin toplam direnci\u00a0 2,02Ohm olur. Sigorta \u00f6ncesi devrenin direnci 0,53Ohm idi. Toplam \u00e7evrim empedans\u0131 2,55 Ohm olmaktad\u0131r. Yang\u0131n ko\u015fullar\u0131nda toplam hata ak\u0131m\u0131<\/p>\n<p>230V\/2,55Ohm =89,9A olur.<\/p>\n<p>C tipi sigortam\u0131z\u0131n ani a\u00e7ma e\u015fik de\u011feri 160A idi. 89,9&lt;160A oldu\u011fu i\u00e7in koruma ger\u00e7ekle\u015fmeyecektir. E\u011fer B tipi sigorta kullan\u0131l\u0131rsa, ani a\u00e7ma de\u011feri anma ak\u0131m\u0131n\u0131n 5 kat\u0131 olur. 16Ax5=80A ani a\u00e7ma s\u0131n\u0131r\u0131n\u0131n alt\u0131nda kal\u0131nd\u0131\u011f\u0131ndan (89,9&gt;80A) koruma ger\u00e7ekle\u015fecektir.<\/p>\n<p>Elbette se\u00e7ilen sigorta e\u011frisinin ekipman\u0131n yolalma ak\u0131m\u0131na uygun olup olmad\u0131\u011f\u0131na bakmak gerekir. Yolalma ak\u0131m\u0131na uygun bir bir e\u011fri bulunam\u0131yorsa, kablo kesiti de\u011fi\u015ftirilecektir.<\/p>\n<p>Yukar\u0131daki \u00f6rne\u011fimizdeki hesap y\u00f6ntemini a\u015fa\u011f\u0131daki excel tablosunda kullanabilirsiniz.<\/p>\n<p style=\"text-align: center;\"><iframe loading=\"lazy\" src=\"https:\/\/onedrive.live.com\/embed?resid=5E384BA25F057C18%21131&amp;authkey=%21AMRuTYxP_4mf9NQ&amp;em=2&amp;wdAllowInteractivity=False&amp;AllowTyping=True&amp;Item='Sayfa2'!B40%3AF60&amp;wdHideGridlines=True&amp;wdDownloadButton=True&amp;wdInConfigurator=True\" width=\"457\" height=\"450\" frameborder=\"0\" scrolling=\"no\"><\/iframe><\/p>\n<h5>4. Gerilim D\u00fc\u015f\u00fcm\u00fc<\/h5>\n<p>Normal \u015fartlarda gerilimin izin verilen s\u0131n\u0131rlar i\u00e7inde olmas\u0131 elektrikli cihazlar\u0131n fonksiyonlar\u0131n\u0131 yerine getirmesi a\u00e7\u0131s\u0131ndan son derece \u00f6nemlidir. (Gerilim d\u00fc\u015f\u00fcm\u00fc ile ilgili yaz\u0131m\u0131z\u0131 <a href=\"http:\/\/www.benga.pro\/index.php\/2018\/01\/11\/gerilim-dusumu\/\">buraya t\u0131klayarak<\/a> okuyabilirsiniz.) Yang\u0131n an\u0131nda \u00e7al\u0131\u015facak acil durum ekipmanlar\u0131 i\u00e7in %10&#8217;a kadar gerilim d\u00fc\u015f\u00fcm\u00fcne m\u00fcsaade edilir.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-3940 aligncenter\" src=\"http:\/\/www.benga.pro\/wp-content\/uploads\/2020\/04\/FS110-Fire-rated-alarm-cable_700x434-300x186.jpg\" alt=\"\" width=\"300\" height=\"186\" \/><\/p>\n<p>Yang\u0131n pompalar\u0131n\u0131n durumu ise NFPA&#8217;de \u015f\u00f6yledir.<\/p>\n<p><em>Kesit se\u00e7iminde y\u00fck ak\u0131m\u0131 olarak pompan\u0131n tam y\u00fck ak\u0131m\u0131n\u0131n %125ine, jokey pompa ile di\u011fer pompa aksesuarlar\u0131n\u0131n tam y\u00fck\u00fcn\u00fcn ilave edilerek bulunmas\u0131 istenmektedir. Gerilim d\u00fc\u015f\u00fcm\u00fc hesab\u0131 yaparken ilk \u00e7al\u0131\u015ft\u0131rma an\u0131nda pompa klemenslerinde nominal gerilimin maksimum %15 d\u00fc\u015fmesine, normal \u00e7al\u0131\u015fmada ise nominal ak\u0131m\u0131n\u0131n 1.15 kat\u0131 esas al\u0131narak maksimum %5 d\u00fc\u015fmesine m\u00fcsaade edilir. (<strong>Bak\u0131n\u0131z G\u00fc\u00e7 Kablolmas\u0131 i\u00e7in NFPA70 Art.695.6 , gerilim d\u00fc\u015f\u00fcm\u00fc i\u00e7in NFPA 70 Art.695.7)<\/strong><\/em><\/p>\n<p>Gerilim d\u00fc\u015f\u00fcm\u00fcn\u00fcn(dU) form\u00fcl\u00fc a\u015fa\u011f\u0131da verilmi\u015ftir.<\/p>\n<p><strong>dU= \u221a3 . I . (R . cos\u00d8 + X . sin\u00d8)<\/strong><\/p>\n<p>Burada I y\u00fck ak\u0131m\u0131, R, t\u00fcm devrenin direncinin temsil etmekte, X ise yine t\u00fcm devrenin reaktans\u0131n\u0131 temsil etmektedir. Burada reaktans\u0131 ihmal edelim ve form\u00fcl\u00fcm\u00fcz<\/p>\n<p><strong>dU= \u221a3 . I . R . cos\u00d8<\/strong><\/p>\n<p>olsun.<\/p>\n<p>Yukar\u0131daki b\u00f6l\u00fcmlerde g\u00f6r\u00fcld\u00fc\u011f\u00fc gibi, yang\u0131n durumunda R direnci \u00e7ok y\u00fcksek de\u011ferlere \u00e7\u0131kmaktad\u0131r. Bu durumda olu\u015facak gerilim d\u00fc\u015f\u00fcm\u00fc de artacakt\u0131r. Ancak burada bir ayr\u0131nt\u0131ya dikkat etmek gerekir. Genelde yang\u0131n kablosunun t\u00fcm\u00fcn\u00fcn yang\u0131na maruz kalmas\u0131 beklenmez \u00e7\u00fcnk\u00fc kablo farkl\u0131 yang\u0131n zonlar\u0131ndan ge\u00e7iyor olabilir. B\u00f6yle bir durumda yang\u0131na maruz kalan k\u0131sm\u0131nda diren\u00e7 art\u0131\u015f\u0131 olacak, di\u011fer k\u0131sm\u0131nda ise normal diren\u00e7 de\u011ferleri ge\u00e7erli olacakt\u0131r. Haliyle gerilim d\u00fc\u015f\u00fcm\u00fc hesab\u0131nda devreyi, yang\u0131na maruz kalan k\u0131s\u0131m ve normal k\u0131s\u0131m olarak 2 k\u0131sma ay\u0131rmak gerekecektir.<\/p>\n<p>A\u015fa\u011f\u0131daki \u015fekilde verilen \u00f6rnekte, g\u00fc\u00e7 fakt\u00f6r\u00fc 0,8 olan ve anma ak\u0131m\u0131 In=225A olan yang\u0131n pompas\u0131 vard\u0131r. Bu pompan\u0131n besleme paneline kadar %1 gerilim d\u00fc\u015f\u00fcm\u00fc oldu\u011fu bilinmektedir. Panelinden sonra 100m 3&#215;70+35 N2XH FE180 besleme kablosu vard\u0131r. Yang\u0131n an\u0131nda bu kablonun 20m lik k\u0131sm\u0131 yang\u0131na maruz kalmaktad\u0131r. Olu\u015facak gerilim d\u00fc\u015f\u00fcmlerini inceleyelim.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-3935 aligncenter\" src=\"http:\/\/www.benga.pro\/wp-content\/uploads\/2020\/04\/du-1-300x70.jpg\" alt=\"\" width=\"364\" height=\"85\" \/><\/p>\n<p>NFPA&#8217;ye g\u00f6re yang\u0131n pompalar\u0131nda nominal ak\u0131m\u0131n\u0131n 1.15 kat\u0131 esas al\u0131narak maksimum %5 d\u00fc\u015fmesine m\u00fcsaade edildi\u011fini belirtmi\u015ftik. O halde hesaplar\u0131m\u0131zda kullanaca\u011f\u0131m\u0131z ak\u0131m de\u011feri 225&#215;1,15 = 258,75A olacakt\u0131r.<\/p>\n<p><strong>a-)<\/strong> \u00d6nce, yang\u0131n\u0131n olmad\u0131\u011f\u0131 durumu de\u011ferlendirelim. Normal \u015fartlarda 90\u00baC iletken s\u0131cakl\u0131\u011f\u0131nda 70mm2 bak\u0131r iletkenin direnci 0,342mOhm\/m dir. 100m kablo i\u00e7in bu de\u011fer 0,0342Ohm olur.<\/p>\n<p>dU= \u221a3 . I . R . cos\u00d8 = \u221a3 . 258,75 . 0,0342 . 0,8 = 12,26 V<\/p>\n<p>%dU=12,26\/400= %3,07 + %1 =%4,07<\/p>\n<p><strong>b-)<\/strong> Yang\u0131n\u0131n oldu\u011fu durumu de\u011ferlendirelim. Normal \u015fartlarda 90\u00baC iletken s\u0131cakl\u0131\u011f\u0131nda 70mm2 bak\u0131r iletkenin direnci 0,342mOhm\/m dir. 80m kablo i\u00e7in bu de\u011fer 0,02736Ohm olur. 1000\u00baC iletken s\u0131cakl\u0131\u011f\u0131nda 70mm2 bak\u0131r iletkenin direnci 1,42mOhm\/m dir. 20m kablo i\u00e7in bu de\u011fer 0,0284Ohm olur. Toplam diren\u00e7 0,05576Ohm olur.<\/p>\n<p>dU= \u221a3 . I . R . cos\u00d8 = \u221a3 . 258,75 . 0,05576 . 0,8 = 19,99 V<\/p>\n<p>%dU=19,99\/400= %5,00 + %1 =%6,00<\/p>\n<p>Yang\u0131n an\u0131nda %5 ko\u015fulu sa\u011flanmad\u0131\u011f\u0131ndan 70mm2 kesit uygun de\u011fildir.<\/p>\n<p><strong>c-)<\/strong> Yang\u0131n\u0131n oldu\u011fu durumu 3&#215;95+50 N2XH FE180 kablo ile de\u011ferlendirelim. Normal \u015fartlarda 90\u00baC iletken s\u0131cakl\u0131\u011f\u0131nda 95mm2 bak\u0131r iletkenin direnci 0,25mOhm\/m dir. 80m kablo i\u00e7in bu de\u011fer 0,02Ohm olur. 1000\u00baC iletken s\u0131cakl\u0131\u011f\u0131nda 95mm2 bak\u0131r iletkenin direnci 1,06mOhm\/m dir. 20m kablo i\u00e7in bu de\u011fer 0,0212Ohm olur. Toplam diren\u00e7 0,0412Ohm olur.<\/p>\n<p>dU= \u221a3 . I . R . cos\u00d8 = \u221a3 . 258,75 . 0,0412 . 0,8 = 14,77 V<\/p>\n<p>%dU=14,77\/400= %3,69+%1 =%4,69<\/p>\n<p>Yang\u0131n an\u0131nda %5 ko\u015fulu sa\u011fland\u0131\u011f\u0131ndan 95mm2 kesit uygundur.<\/p>\n<p>Bilindi\u011fi gibi motorlarda moment, gerilimin karesi ile orant\u0131l\u0131d\u0131r. Yani gerilimdeki %10 d\u00fc\u015fme, motor momentinde %19 d\u00fc\u015fmeye neden olur. Bu durum baz\u0131 motorlarda motorun \u00e7al\u0131\u015famaz duruma gelmesine neden olur. Ayr\u0131ca bilindi\u011fi gibi motorlar, yol alma an\u0131nda olduk\u00e7a y\u00fcksek ak\u0131m \u00e7ekerler. Yol alma durumunda gerilim d\u00fc\u015f\u00fcm\u00fc daha fazla olacakt\u0131r. Motor, yang\u0131n ba\u015flad\u0131ktan sonra devreye girebilir. Bu nedenle, yine k\u00f6t\u00fc senaryoya g\u00f6re yani kablonun yang\u0131na maruz kald\u0131\u011f\u0131 d\u00fc\u015f\u00fcn\u00fclerek yolalma i\u00e7in gerilim d\u00fc\u015f\u00fcm\u00fc hesab\u0131 da yap\u0131lmal\u0131d\u0131r. NFPA&#8217;ye g\u00f6re yol alma an\u0131nda %15 gerilim d\u00fc\u015f\u00fcm\u00fcne izin verilmektedir. Bunun i\u00e7in yine a\u015fa\u011f\u0131daki form\u00fcl\u00fc kullanabiliriz.<\/p>\n<p><strong>dU= \u221a3 . I . (R . cos\u00d8 + X . sin\u00d8)<\/strong><\/p>\n<p>Ama bu sefer I, yolalma ak\u0131m\u0131; cos\u00d8, yol alma esnas\u0131ndaki g\u00fc\u00e7 fakt\u00f6r\u00fc; R besleme devresi direnci;X ise besleme devresi reaktans\u0131d\u0131r. Bu form\u00fclde X, reaktans\u0131 ihmal etmeden kullanmak gerekir. \u00c7\u00fcnk\u00fc cos\u00d8 k\u00fc\u00e7\u00fck olacakt\u0131r ama sin\u00d8 y\u00fcksek olacakt\u0131r. \u00dcstelik y\u00fcksek yolalma ak\u0131m\u0131yla \u00e7arp\u0131l\u0131nca da kayda de\u011fer bir rakam olu\u015facakt\u0131r.<\/p>\n<h5>5. \u00d6zet<\/h5>\n<p>Yang\u0131n an\u0131nda iletkenin \u00e7ok y\u00fcksek s\u0131cakl\u0131klara maruz kalmas\u0131yla iletkenin direnci \u00f6nemli miktarda artar. Bu art\u0131\u015f, devrenin karakterini tamam\u0131yla de\u011fi\u015ftirir. Gerek iletkenin ak\u0131m ta\u015f\u0131ma kapasitesi, gerek devrenin korunmas\u0131\u00a0 gerekse gerilim d\u00fc\u015f\u00fcm\u00fc hesaplar\u0131 bu diren\u00e7 art\u0131\u015f\u0131ndan \u00f6nemli derecede etkilenir. Haliyle yang\u0131n an\u0131nda \u00e7al\u0131\u015facak ekipmanlar\u0131n kablo kesitini se\u00e7erken bu ba\u015fl\u0131klar\u0131n tek tek g\u00f6zden ge\u00e7irilerek do\u011fru kesitin se\u00e7ilmesi \u00f6nemlidir.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Binalarda yang\u0131n s\u0131ras\u0131nda baz\u0131 elektrikli ekipmanlar\u0131n en az\u0131ndan belli bir s\u00fcre boyunca \u00e7al\u0131\u015fmas\u0131n\u0131n sa\u011flanmas\u0131 gerekmektedir. Mesela binada yang\u0131n s\u00f6nd\u00fcrme sistemi pompalar\u0131 varsa, bu pompalar\u0131n yang\u0131na dayan\u0131kl\u0131 kablolarla beslenmesi gereklidir ki yang\u0131n esnas\u0131nda \u00e7al\u0131\u015fabilsin ve yang\u0131n\u0131n s\u00f6nd\u00fcr\u00fclmesine katk\u0131da bulunabilsin. E\u011fer bu pompalar normal kablolar ile beslenirse, yang\u0131n an\u0131nda 900\u00baC s\u0131cakl\u0131k mertebelerinde \u0131s\u0131ya maruz kal\u0131p \u00e7abucak yanacak&hellip;&nbsp;<a href=\"https:\/\/benga.pro\/index.php\/2020\/04\/12\/yangin-kablosu-kesit-hesabi\/\" rel=\"bookmark\"><span class=\"screen-reader-text\">Yang\u0131n kablosu kesit hesab\u0131<\/span><\/a><\/p>\n","protected":false},"author":3,"featured_media":3941,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"","neve_meta_content_width":0,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","_themeisle_gutenberg_block_has_review":false,"footnotes":""},"categories":[5,49],"tags":[278,245,170,67,174,175],"class_list":["post-3908","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-elektrik-tesisat","category-teknik-konular","tag-akim-tasima","tag-fe180","tag-fire","tag-gerilim-dusumu","tag-yangin","tag-yangin-kablosu"],"_links":{"self":[{"href":"https:\/\/benga.pro\/index.php\/wp-json\/wp\/v2\/posts\/3908","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/benga.pro\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/benga.pro\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/benga.pro\/index.php\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/benga.pro\/index.php\/wp-json\/wp\/v2\/comments?post=3908"}],"version-history":[{"count":1,"href":"https:\/\/benga.pro\/index.php\/wp-json\/wp\/v2\/posts\/3908\/revisions"}],"predecessor-version":[{"id":4270,"href":"https:\/\/benga.pro\/index.php\/wp-json\/wp\/v2\/posts\/3908\/revisions\/4270"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/benga.pro\/index.php\/wp-json\/"}],"wp:attachment":[{"href":"https:\/\/benga.pro\/index.php\/wp-json\/wp\/v2\/media?parent=3908"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/benga.pro\/index.php\/wp-json\/wp\/v2\/categories?post=3908"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/benga.pro\/index.php\/wp-json\/wp\/v2\/tags?post=3908"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}