Short Circuit Calculation Spreadsheet Simple tool designed for data estimation and conservative short circuit scenarios. In this way, we apply the coefficients and factors of the ANSI and IEC standards, compare the results with the data published by the manufacturers and others issue alarms and warnings when the devices are exceeded in their capacity.

The revision and verification of norms is continuous to seek its permanent validity.

The Short Circuit module and the Protection Selectivity module are perfectly integrated with the Electric Arc module to carry out the calculation of risks due to the presence of the electric arc.

General Capabilities

• Calculation of three-phase, single-phase (LG) and biphasic ( LL, & LLG) fault currents (faults ).
• Evaluation of devices according to total or maximum fault current.
• Automatic adjustment of resistance and length of conductors (both lines and cables)
• Global or individual tolerance setting in the device impedance for maximum or minimum fault current.
• Fault impedance modeling for unbalanced faults.
• Parallel shunts for branches and capacitive loads (unbalanced faults)
• Graphic or bar chart selection to calculate the fault current.
• Automatically determines the fault current in motor terminals without adding additional busbars.
• The offset introduced by the transformers can be included in the calculation.
• Grounding models for motors, generators and transformers.
• It allows to calculate the contribution of motors according to load category, demand factor or both.
• Availability of verifying manufacturer’s data sheets included in bookstores.

ANSI / IEEE regulations

• Evaluation of equipment in single-phase and frame systems
• Determines the maximum and minimum fault current
• Calculation of ½ cycle current, 1.5-4 cycles, and 30 cycles, for balanced and unbalanced faults (three-phase, single-phase and two-phase)
• Verification of the momentary capacity and interruption of the devices
• Checking the closing & latching
• Evaluation of symmetrical capacities or nominal total of the switches
• Special handling of generator switches for generator and system faults
• Interruption capacity depending on the contact opening time of the switch, according to regulations or defined by the user
• If the user defines the coefficient it is automatically included not contemplate the decay of the AC component in the calculation of failure (NACD)
• User options for automatic adjustment of HVCB contribution levels

Reporting (ANSI & IEC)

• Fault reports on load terminals
• Exceeded equipment is automatically highlighted
• Current profiles (Ia, Ib, Ic, I1, I2, & I0)
• Voltage profiles (Va, Vb, Vc, V1, V2, & V0)
• Individual contribution of current lack for Isym, Ia, & 3I0
• Phase and sequence impedances (+, -, 0)
• View of alerts that allows you to visualize the violations of the marginal and critical limits
• Export single-line diagrams to CAD file processing systems
• Input data, detailed individual or total contributions of short circuits, and summaries
• Visualization of results in graphs of last generation.
• Export results report in recognizable format by editing software
• Customizable Crystal Report® customizable viewer

IEEE C37.04 Standard Rating Structure for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Including Supplements: C37.04f IEEE, IEEE C37.04g, C37.04h IEEE, IEEE C37.04i

IEEE C37.010 Standard Application Guide for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current

IEEE C37.010b Standard and Emergency Load Current-Carrying Capability

IEEE C37.010e Supplement to IEEE C37.010

IEEE C37.13 Standard for Low-Voltage AC Power Circuit Breakers Used in Enclosures

IEEE C37.013 Standard for High-Voltage AC Generator Circuit Breakers Rated on a Symmetrical Current Basis

C37.20.1 IEEE Standard for Low-Voltage Metal Enclosed Power Switchgear Circuit Breaker

IEEE 399 Power System Analysis – the Brown Book

IEEE 141 Electric Power Distribution for Industrial Plants – the Red Book

IEEE242 IEEE Recommended Practice for Protection and Coordination of Industrial and Commercial Power Systems – the Buff Book

UL 489_9 Standard for Safety for Molded-Case Circuit Breakers, Molded-Case Switches, and Circuit Breaker Enclosures

IEC Regulations

• Evaluation of equipment in single-phase and frame systems, UPS
• Calculation of three-phase, single-phase (LG) and biphasic (LL, & LLG) fault intensities
• Calculation of transient short-circuit IEC 61363
• Compares rated equipment capacities against calculated fault values
• The user can define the voltages of the factor “c”
• Cutting capacity of low voltage switches according to nominal or maximum rated capacity
• Different methodologies are used to calculate the R / X ratio
• The phase shift introduced by the transformers can be included in the calculation
• Negative or positive impedance settings for max / min lk˝ & Ik
• Automatic application of correction factors K (ie, KT, KG, KSO)
• Automatically determines mesh and non-mesh networks to calculate Ib, Ik, & Idc
• The Ib value of mesh in mesh is adjusted with the individual contributions of machines to improve accuracy
• Short circuits are considered both distant and near the generator
• Generates compatible relay test set graphs for transient short circuits
• Detailed IEC Team Evaluation Reports and Full Contributions for Unbalanced Faults

IEC 62271-100 High-Voltage Switchgear and Controlgear, Part 100: High-Voltage Alternating-Current Circuit Breakers

IEC 62271-200 High-Voltage Switchgear and Controlgear, Part 200: AC Metal-Enclosed Switchgear and Controlgear for Rated Voltages Above 1 kV and up to and including 52 kV

IEC 62271-203 High-Voltage Switchgear and Controlgear,

Part 203: Gas-Insulated Metal-Enclosed Switchgear for Rated Voltages Above 52 kV

IEC 60282-2 High-Voltage Fuses, Part 2: Expulsion Fuses

IEC 60909-0 Short Circuit Currents in Three-Phase AC Systems, Part 1: Calculation of Currents (including 2002 Corrigendum 1)

IEC 60909-1 Short Circuit Currents in Three-Phase AC Systems, Part 1: Factors for the Calculation of Short Circuit Currents According to IEC 60909-0

IEC 60909-2 Electrical Equipment – Data for Short Circuit Current Calculations in Accordance with IEC 909 (1988)

IEC 60909-4 Short Circuit Currents in Three-Phase AC Systems, Part 4: Examples for the Calculation of Short Circuit Currents

IEC 60947-1 Low Voltage Switchgear and Controlgear,

Part 1: General Rules

IEC 60947-2 Low Voltage Switchgear and Controlgear,

Part 2: Circuit Breakers

IEC 61363-1 Electrical Installations of Ships and Mobile and Fixed Offshore Units, Part 1: Procedures for Calculating Short Circuit Currents in Three-Phase AC

Flexible Operation:

• Calculation of three-phase, single-phase (LG) and biphasic (LL, & LLG) fault currents (faults).
• Availability of verifying manufacturer’s data sheets included in bookstores.
• Automatically takes into account all the multiplier factors required depending on the type of calculation.
• Automatically adjusts the interruption capacity of equipment based on pre-fault or nominal voltage.

Calculation options:

• The user defines the pre-fault (fault) (ANSI) and the “c” (IEC) voltages.
• Different methodologies are used to calculate the R / X (IEC) ratio.
• It allows setting the marginal and critical limits for verification of exceeded equipment.
• It includes the action of the thermal devices in the calculation of short circuit.
• There are no limitations on voltage levels.
• It allows to calculate the contribution of motors according to the categories of load.
• Additional impedances can be included for the calculation of ground faults.
• Unlimited number of bars * and elements.
• Automatic error checking.
• Graphical display of exceeded equipment.
• Graphical display of bars with low / over voltage.
• It allows to simulate island subsystems.
• It allows to take into account radial or ring systems.
• Possibility of integrating single-phase, three-phase and CC systems into the same project.
• It allows simulating the effect of several generators in line, as well as connections to external networks.
• It allows to use library of customized equipment by the user.
• Graphically displays results directly on the single-line diagram with user-configurable formats dynamically.
• Graphical display of impedance of equipment and grounding.
• It takes into account the effect of the impedance of the feeders to motors in the decay of the contribution to the fault current (as Option)

* The maximum number of energized bars to be taken into account in the calculation is subject to license restrictions.

Calculations available

• Verification of the making and breaking capacity of cutting equipment.
• Verification of the closing-latching and interrupting capacity of cutting equipment.
• Automatic comparison of results for cuts in 2, 3, 5, and 8 cycles.
• The user can define the contact parting time (ANSI).
• Cut cycle depending on the delay in the opening of the switch.
• Interrupt cycle depending on the contact parting time (ANSI) of the switch.
• Calculation of capacity for switches associated with generators.
• Contribution of engines to faults according to load categories.
• Calculation of Ith and verification of capacity according to IEC.
• Cable impedance adjustment by temperature.
• Selection by user of the bars to be considered missing (graph or tables).
• Grounding models for motors, generators and transformers.
• Effect of impedances in the calculation of ground faults (ANSI & IEC).
• If the user defines it, the coefficient that does not contemplate the decay of the AC component in the calculation is automatically included.
• Ability to report interrupt capacity vs. Delay in the breaker opening delay (IEC).
• Effect of transformers connections on unbalanced faults (ANSI).

Calculation of single-phase circuits

• Calculation of overload and evaluation of single-phase, three-phase, UPS systems and systems.
• ANSI and IEC standards are used to calculate the short-circuit current for network points belonging to the main boards, sub-boards, UPSs and phase adapters.
• It compares the current of the devices in these networks to evaluate protection equipment and automatically generate critical alerts and marginal alerts based on user-defined alarm limits.