SHORT FEATURES
· Quickly Calculates Short Circuit Currents
· Computes Bolted Three Phase and Ground Faults
· Allows for Single and Three Phase Systems
· Allows Up to 2000 buses and 1500 Motors
· Uses "Per Unit" Method of Calculation
· Works both in Metric and English Units
· References Built-in "X" and "R" Values
· Full Screen Input and Editing Features
· Electronic Mouse Support
· Menu Driven with On-line Help Screens
· User Definable "X" and "R" Data Tables
· Compatible with the VDROP and PANEL Programs
· Provides Comprehensive and Concise Reports
· Ability to Print to Screen, Printer, or Disk File
· Reports are Manually Verifiable

The Elite Software Short Circuit Calculation DOS based program is a powerful yet easy to use tool that allows the designer to quickly obtain the maximum potential short circuit current at each node (bus) in a radial electric power distribution system with up to 2,000 components. Any combination of motors, generators, and capacitor banks up to a total of 1,500 is also allowed. The resistance and reactance data for all types of electrical components are stored on disk and automatically accessed by the program as needed. Specifically, "X" and "R" values are included for copper and aluminum cables, ACSR overhead cables, busway, switches, circuit breakers, current and voltage transformers, non-time delay and dual element fuses. All of the "X" and "R" values can be viewed and edited by the user.

In addition, provision is made for the input of "special" components whereby the user can define his own "X" and "R" values for a non-standard device. Perhaps the most unique feature of the program is its ability to accurately handle motor and generator contributions. Many programs of this type, even some running on mainframe computers, do not properly account for motor loads as they simply have the user add the motor contribution to the utility source KVA. The SHORT program allows motors and generators to be placed anywhere in the network. The contribution from each motor and the utility source is vectorally added at every point where they intersect. This provides an extremely accurate analysis of the maximum current any node can be subject to. Finally, the fact that SHORT works in conjunction with PANEL and VDROP makes it especially useful.

PROGRAM INPUT
The Short Circuit program uses full screen editing features that provide a simple "fill in the blank" input procedure. All input data is checked at the time of entry so that no improper data can be entered. If you have a question about what the program is requesting, type a "?" and the program will offer additional explanations about the input data being requested. Upon completion of the input process, all data is saved to disk and can be reviewed and edited whenever desired. Two types of data are requested: general project data and specific electrical component data.

The general project data includes the project name, client name, designer name, base KVA, initial short circuit KVA available, initial X/R ratio, and voltage at the first node of the system. Specific component data includes the component type (cable, busduct, transformer, switch, circuit breaker, fuse, etc.), the beginning and ending node numbers for each component, component size, length if applicable, and any other information necessary for defining a particular type of component. Input sheets are also provided for the easy organization of your data.

PROGRAM OUTPUT
The Short Circuit program provides two basic types of reports that can be printed either to the screen or the printer. The first report is a nicely formatted presentation of all the input data given for the project. The second report lists the symmetrical and asymmetrical fault current at each node (bus) in the network. Both three phase (bolted faults) and phase to neutral (ground faults) currents can be printed with and without motor and generator contributions. In addition, the X/R ratio and the per unit "X" and "R" values are listed for each node. These values are given so that manual verification of the fault currents can be more easily performed. See the sample reports on this page.

CALCULATION METHOD
The Short Circuit program uses the "per unit" method of calculation as described in the IEEE Std 241-1983 entitled "Electric Power Systems in Commercial Buildings", otherwise known as the "Gray Book". The per unit method was used so that many different voltages can exist throughout the network. This method also makes it easy to account for single and three phase systems operating at either 50 or 60 Hertz. The Short Circuit program is supplied with built-in "X" and "R" values for the various electrical components.

These values were taken from several sources including the Bussmann's manual called "A Simple Approach to Short Circuit Calculations", the Federal Electric Pacific Catalog, and the GE Industrial Power Systems Data Book. However, these "X" and "R" values can be easily revised to any values that the user desires. Besides revising existing values, the Short Circuit program also allows the user to create additional "X" and "R" table files so that many different types of data can be referenced. The program calculation method is explained in detail in the user's manual so that exact manual verification can be performed to check the program results.