by means of a melting bath earthed by bottom electrodes offers great safety for\noperating personnel, and can sometimes also give an indication of the condition\nof the crucible. In this system, the insulation value between the voltage-carrying\nfurnace coil and the earth potential is determined by means of direct current\nmeasurement. In the case of proper electrical insulation between the coil and the\niron piles, and the high-current system, the power supply and the earth potential,\na low insulation value can be attributed to the resistance between the coil and the\nearthed melting bath, and thus also the condition of the crucible (page 98).\n<\/p>\n\n\n\n
In the case of a newly concreted coil installation with coil plastering, the poor resist-\nance value is usually due to the high moisture content. At resistance values below\n400 Ohms, a crucible induction furnace should therefore not be operated at above\n1,000 Volt operating voltage. From 400 \u2013 700 Ohms, a level of 1,500 Volt should not\nbe exceeded, since in addition to the measured \u201cearth short\u201d due to moisture\nbetween the coil and earth, the winding voltage can also lead to winding shorts. At\napprox. 60 Volt winding voltage and mains frequency, there is a winding insulation\nof 3 mm. In the moist condition, the winding voltage should be no more than\n10 V\/mm, or in other words 30 Volt. In the case of medium-frequency furnaces, one\nhas winding voltages of up to 270 Volt and 15 mm of intermediate layer insulation,\nso that consequently a winding voltage of 150 V should not be exceeded.\n<\/p>\n","protected":false},"excerpt":{"rendered":"
by means of a melting bath earthed by bottom electrodes offers great safety for operating personnel, and can sometimes also give an indication of the condition of the crucible. In this system, the insulation value between the voltage-carrying furnace coil and the earth potential is determined by means of direct current measurement. In the case … Continue reading Insulation monitoring<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[2],"tags":[],"class_list":["post-1374","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"acf":{"adresse":"","telefon":"","e-mail":"","webseite":""},"_links":{"self":[{"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/posts\/1374","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/comments?post=1374"}],"version-history":[{"count":1,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/posts\/1374\/revisions"}],"predecessor-version":[{"id":1375,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/posts\/1374\/revisions\/1375"}],"wp:attachment":[{"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/media?parent=1374"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/categories?post=1374"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/tags?post=1374"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}