{"id":494990,"date":"2024-11-05T12:51:22","date_gmt":"2024-11-05T12:51:22","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/as-38511991-r2015\/"},"modified":"2024-11-05T12:51:22","modified_gmt":"2024-11-05T12:51:22","slug":"as-38511991-r2015","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/as\/as-38511991-r2015\/","title":{"rendered":"AS 3851:1991 (R2015)"},"content":{"rendered":"<p>Specifies standard methods for the calculation of short-circuit currents in three-phase a.c. systems, both radial and meshed with and without contribution from generators and motors, which are suitable for either computer or manual calculation. <\/p>\n<p><b>Scope<\/b><\/p>\n<p> This Standard specifies a standardized procedure for the calculation of prospective short-circuit currents in the fault for- <br \/> (a) low voltage a.c. systems; and <br \/> (b) high voltage three-phase a.c. systems, operating at a nominal frequency of 50 Hz. <br \/> The procedure is intended to be, as far as possible, in a form to facilitate its use by non-specialist engineers. <br \/> NOTE: The procedure is applicable generally to other frequencies close to 50 Hz; however, care should be exercised in the use of frequency-dependent factors. <br \/> Except in Appendix A, the basis of the calculation procedure in this Standard is ohmic. Appendix A converts this procedure to per-unit calculation. <br \/> NOTE: Worked examples are provided in Appendices D and E on ohmic and per unit basis respectively. <br \/> The current, calculated in this Standard forms the basis for the determination of the currents in the paths feeding the fault. <br \/> This Standard specifies a standardized method for the calculation of the joule integral (I2t) of a short-circuit current. <br \/> This Standard does not cover- <br \/> (i) short-circuits deliberately created under controlled conditions as in short-circuit testing stations; <br \/> (ii) short-circuits in the electrical installations of ships and aircraft; <br \/> (iii) non-simultaneous short-circuits, which can lead to higher aperiodic components of short-circuit current; or <br \/> (iv) methods for analysis of short-circuit currents in non-linear systems.<\/p>\n","protected":false},"excerpt":{"rendered":"<p><b>The calculation of short-circuit currents in three-phase a.c. systems<\/b><\/p>\n<table style=\"width: 100%\" border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td>Published By<\/td>\n<td>Publication Date<\/td>\n<td>Number of Pages<\/td>\n<\/tr>\n<tr>\n<td><a href=\"https:\/\/pdfstandards.shop\/product-category\/publishers\/as\/\"><b>AS<\/b><\/a><\/td>\n<td>1991-05-13<\/td>\n<td>101<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":495003,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[285,2633],"product_tag":[],"class_list":{"0":"post-494990","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-17-220-20","7":"product_cat-as","9":"first","10":"instock","11":"sold-individually","12":"shipping-taxable","13":"purchasable","14":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/494990","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/495003"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=494990"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=494990"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=494990"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}