IEC 60865-1:2011 is applicable to the mechanical and thermal effects of short-circuit currents. It contains procedures for the calculation of: the electromagnetic effect on rigid conductors and flexible conductors, the thermal effect on bare conductors. For cables and insulated conductors, reference is made, for example, to IEC 60949 and IEC 60986. For the electromagnetic and thermal effects in d.c. auxiliary installations of power plants and substations reference is made to IEC 61660-2. Only a.c. systems are dealt with in this standard. This third edition cancels and replaces the second edition published in 1993 and constitutes a technical revision. The main changes with respect to the previous edition are: – The determinations for automatic reclosure together with rigid conductors have been revised. – The influence of mid-span droppers to the span has been included. For vertical cable-connection the displacement and the tensile force onto the lower fixing point may now be calculated. Additional recommendations for foundation loads due to tensile forces have been added. The subclause for determination of the thermal equivalent short-circuits current has been deleted (it is now part of IEC 60909-0). The regulations for thermal effects of electrical equipment have been deleted. The standard has been reorganized and some of the symbols have been changed to follow the conceptual characteristic of international standards.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 6<\/td>\n | English CONTENTS <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | 1 Scope 2 Normative references <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | 3 Terms, definitions, symbols and units 3.1 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 3.2 Symbols and units <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 4 General <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 5 Rigid conductor arrangements 5.1 General 5.2 Calculation of electromagnetic forces <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 5.3 Effective distance between main conductors and between sub-conductors <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | Figures Figure 1 \u2013 Factor k1s for calculating the effective conductor distance <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 5.4 Calculation of stresses in rigid conductors Tables Table 1 \u2013 Effective distance as between sub-conductorsfor rectangular cross-section dimensions <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | Figure 2 \u2013 Loading direction and bending axis for multiple conductor arrangements <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | Table 2 \u2013 Maximum possible values of V\u03c3mVrm, V\u03c3sVrs, VFVrm <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | Table 3 \u2013 Factors \u03b1, \u03b2, \u03b3 for different busbar support arrangements <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 5.5 Structure loads due to rigid conductors 5.6 Consideration of automatic reclosing <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 5.7 Calculation with special regard to conductor oscillation Table 4 \u2013 Factor q Table 5 \u2013 Section moduli Wm of main conductors with two or more stiffening elements between two adjacent supports <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | Figure 3 \u2013 Factor e for the influence of connecting pieces in Equation (17) <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | Figure 4 \u2013 Factors VF, V\u03c3m and V\u03c3s to be used with the three-phase and line-to-line short-circuits <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 6 Flexible conductor arrangements 6.1 General Figure 5 \u2013 Factors Vrm and Vrs to be used with three-phase automatic reclosing <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 6.2 Effects on horizontal main conductors <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | Figure 6 \u2013 Maximum swing out angle \u03b4max for a given maximumshort-circuit duration Tk1 <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | Figure 7 \u2013 Factor \u03c8 for tensile force in flexible conductors <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Figure\u00a08 \u2013 Geometry of a dropper <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | 6.3 Effects on vertical main conductors (droppers) <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | 6.4 Effects on bundled conductors <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | Figure 9 \u2013 \u03bd2 as a function of \u03bd1 Figure 10 \u2013 \u03bd3 \u00d7 sin\u00a0180\u00b0\/n as a function of as\/d <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | Figure 11 \u2013 \u03be as a function of j and \u03b5st <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | 6.5 Structure loads due to flexible conductors Figure 12 \u2013 \u03b7 as a function of j and \u03b5st <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | 7 The thermal effect on bare conductors 7.1 General 7.2 Calculation of thermal equivalent short-circuit current <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | 7.3 Calculation of temperature rise and rated short-time withstand current density for conductors Table 6 \u2013 Recommended highest temperatures for mechanicallystressed conductors during a short-circuit <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | 7.4 Calculation of thermal short-time strength for different durations of the short-circuit Figure 13 \u2013 Relation between rated short-circuit withstand current density (Tkr = 1 s) and conductor temperature <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | Annex A (normative) Equations for calculation of diagrams <\/td>\n<\/tr>\n | ||||||
| 53<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Short-circuit currents. Calculation of effects – Definitions and calculation methods<\/b><\/p>\n |