The ABNT NBR 5410 and IEC 60364 standards establish criteria for short-circuit protection, but they present divergences regarding the application of the Joule integral, depending on the duration of the short circuit.<\/p>\n
Brazilian standards require that the interrupting capacity of the device be at least equal to the presumed short-circuit current at the point where it is installed, and that the Joule integral that the device allows to pass be less than or equal to the Joule integral required to heat the conductor from the maximum continuous service temperature to the short-circuit limit temperature.<\/p>\n
The IEC 60364 standard includes a note specifying different criteria based on time, distinguishing between short circuits interrupted in less than 0.1 seconds and those lasting up to 5 seconds.<\/p>\n
The German standard VDE 0100 follows the criteria of the IEC 60364 standard. The distinction based on time is due to the application of devices with different characteristics. For times below 0.1 s, the IEC 60364 standard determines that the I\u00b2t value of the protection device must be greater than the specific energy indicated by the manufacturer of the protection device, while for short circuits lasting up to 5 s, the maximum permissible interruption time of the short circuit is calculated, compatible with the thermal capacity of the cable.<\/p>","protected":false},"excerpt":{"rendered":"
A norma ABNT NBR 5410 e a norma IEC 60364 estabelecem crit\u00e9rios para prote\u00e7\u00e3o contra curto-circuito, mas apresentam diverg\u00eancias em rela\u00e7\u00e3o \u00e0 aplica\u00e7\u00e3o da integral de Joule, dependendo do tempo de dura\u00e7\u00e3o do curto-circuito. A norma brasileira exige que a capacidade de interrup\u00e7\u00e3o do dispositivo seja no m\u00ednimo igual \u00e0 corrente de curto-circuito presumida no […]<\/p>\n","protected":false},"author":3,"featured_media":560,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-559","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"yoast_head":"\n