Is IEC 60909-0?
IEC 60909-0:2016 is applicable to the calculation of short-circuit currents in low-voltage three-phase AC systems, and in high-voltage three-phase AC systems, operating at a nominal frequency of 50 Hz or 60 Hz.
What is IEC 60909?
ETAP Short Circuit Analysis complies with IEC 60909 standard, which classifies short-circuit currents according to their magnitudes (maximum and minimum) and fault distances from generators.
What is C factor in short-circuit calculation?
C factor: This is the voltage correction factor (commonly referred to as C Factor). The C Factor is used for modifying equipment impedances and the driving point voltage. IEC recommends calculations for minimum and maximum short circuit currents.
What is initial symmetrical short circuit current?
The initial symmetrical short-circuit current, I”k, is an r.m.s. value of short-circuit current and can be interpreted as – PSCC, defined in this EREC. The peak short-circuit current, ip, is an instantaneous value of the short-circuit current and occurs at the first a.c. peak after fault inception.
What is peak fault current?
The Peak fault occurs first during the asymmetrical state and is the maximum possible instantaneous value of the short circuit current. The r.m.s fault occurs after the Peak fault and is the latter more symmetrical state of the short circuit.
How do you calculate DC fault current?
Divide total SC MVA value by system voltage in kV to get short circuit current value in kA on DC side. For example, to calculate short circuit current value on load side of the transformer rectifier combination, take calculated 2.46 SCMVA value and divide it by 0.30kV.
What is the difference between symmetrical and asymmetrical fault current?
A symmetrical fault is a fault where all phases are affected so that the system remains balanced. The other three fault types (line to ground, line to line, and two- line to ground) are called unsymmetrical or asymmetrical faults.
How do you find symmetrical fault current?
In symmetrical fault, fault currents in phases are symmetrical in the sense that their magnitudes are equal and they are equally displaced by an angle of 120°. Thus, a symmetrical fault may be assumed as a normal case but with high value of current in phases.
What is PSCC electrical?
The prospective short-circuit current (PSCC), available fault current, or short-circuit making current is the highest electric current which can exist in a particular electrical system under short-circuit conditions. It is determined by the voltage and impedance of the supply system.
How do you calculate Ka from MVA?
Prospective fault MVA is root3 x Line kV x prospective kA fault current. With impedance volts of 5% which is typical for a 1250kVA transformer, the secondary fault MVA with negligible impedance on the High Voltage primary supply is 1.25MVA divided by (5 / 100) = 25 MVA.
What is the reference number for IEC 60909?
Numéro de référence Reference number CEI/I EC 60909-Or200 1 COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services NORME I NTE RN AT I O N AL E INTERNATIONAL STANDARD
Is there an IEC standard for short circuit calculation?
As the old IEC Standard (IEC 60909-0: 2001-07: Short-circuit currents in three-phase a.c. systems – Part 0: Calculation of currents) does not included the calculation of currents generated by self-commutated converters, a revision of this standard has been necessary.
Where can I find the IEC Technical Report?
IEC Catalogue – webstore.iec.ch/catalogue The standalone application for consulting the entire – bibliographical information on IEC International Standards, Technical Specifications, Technical Reports and other documents. Available for PC, Mac OS, Android Tablets and iPad. IEC publications search – www.iec.ch/searchpub
How many Electrotechnical terms are there in IEC?
65 000 electrotechnical terminology entries in English and French extracted from the Terms and Definitions clause of IEC publications issued since 2002Some. entries have been collected from earlier publications TC 37, 77, 86 and of IEC CISPR.