Short Circuit Calculator [2021] Free Download
A short circuit calculator is a tool that can help you determine the fault current or short circuit current in a power distribution system. This is important for electrical design engineers to select the appropriate cable specifications, switching and protection devices, and safety measures. In this article, we will show you how to use a short circuit calculator for free using an Excel sheet or a software program.
Short Circuit Calculator Free Download
What is a Short Circuit?
A short circuit is a condition where two conductors with different voltage levels come into contact with each other, creating a low-resistance path for the current to flow. This can result in a very high current that exceeds the normal operating limits of the circuit and can cause damage to the equipment, fire hazards, or electric shocks. A short circuit can be caused by various factors, such as faulty wiring, insulation failure, lightning strikes, or human errors.
Why Do You Need a Short Circuit Calculator?
A short circuit calculator can help you perform point-to-point short circuit calculations on low-voltage systems (600V or less) according to the standards of the National Electrical Code (NEC) and the Institute of Electrical and Electronics Engineers (IEEE). A short circuit calculator can help you determine the following parameters:
The available fault current at any point in the system
The interrupting rating of the circuit breakers or fuses
The arc flash incident energy and personal protective equipment (PPE) requirements
The voltage drop and power loss due to the fault
The cable sizing and derating factors
The selectivity and coordination of the protection devices
How to Use a Short Circuit Calculator for Free?
There are two ways to use a short circuit calculator for free: using an Excel sheet or using a software program. Here are some examples of free short circuit calculators that you can download and use:
Using an Excel Sheet
An Excel sheet is a spreadsheet program that can perform various calculations and functions. You can use an Excel sheet to create your own short circuit calculator or download a ready-made one from online sources. For example, you can download the following Excel sheets for free:
Short Circuit Current Calculator at various Point of Distribution System[^2^]: This Excel sheet can calculate the short circuit current for three-phase and single-phase power circuits using the base kVA method.
Short Circuit And Arc Flash Calculator[^4^]: This Excel sheet can calculate the short circuit current and arc flash incident energy using the equations from NFPA 70E-2003.
To use an Excel sheet for short circuit calculation, you need to enter the input data such as the system voltage, transformer ratings, cable lengths and impedances, and load characteristics. Then, you can view the output data such as the fault current, voltage drop, arc flash energy, and PPE level. You can also modify the formulas and parameters according to your specific needs.
Using a Software Program
A software program is an application that can run on your computer or mobile device. You can use a software program to perform short circuit calculations with more features and functions than an Excel sheet. For example, you can download the following software programs for free:
IEC Short Circuit Calculator Tool with SIMARIS Design[^1^]: This software program is a network calculation tool that can perform short circuit calculations based on real products from Siemens. It can also perform load flow, voltage drop, and energy balance calculations.
Short Circuit Analysis[^3^]: This software program is a simple tool that can perform point-to-point short circuit calculations on low-voltage systems according to c481cea774