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Short Circuit Analysis

Course No.: SC101
CEUs 0.8

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Conference2This course was developed and is taught by Jim Phillips, P.E. Learn how to perform short circuit analysis / calculations and equipment adequacy evaluations. Understand the importance of X/R ratios, symmetrical vs. asymmetrical faults and how series ratings work. Many calculation examples are used to illustrate how to perform an analysis. The methods are based on the IEEE Red and Violet books. This class can be paired with the Protective Device Coordination Class for 2 days of training. This class is loaded with many in class examples and problems for a hands on learning experience.

Jim has developed this course based on over 30 years of extensive experience with industrial, commercial and utility power systems. Even instructors from other training companies have attended Jim’s classes to see how it’s done. You will learn how to conduct a short circuit study.

[About Jim Phillips]

What You Will Receive

 Training manual
Jim’s short circuit calculation worksheets
 Access to Technical articles
Many calculation examples and problems
 8 hours of Continuing Education Credit

Have This Class On-Site at Your Location

You can also have this class conducted on-site at your location.  Contact our Program Director at 800.874.8883 to see about having Jim teach this class to your staff at your company’s facilities.  Contact us for your custom on-site training proposal.



Short Circuit Study Requirements, NEC® 110.9 and 110.10, Interrupting and Withstand Ratings, Data Requirements, Available Utility Short Circuit Current, Conductor Impedance, Source Impedance, X/R Ratio, Per Phase Calculations, Thevenin Equivalent, Impedance

Determining the Source Impedance, Calculating the Conductor Impedance, Conductor Impedance Tables, Conductor Calculation Worksheets.  In Class Problems – Short Circuit Calculations with Conductor Impedance

Transformer Testing and Percent Impedance, X/R Ratio,  Using Percent Impedance for Short Circuit Calculations,  Determining the Source Impedance in Percent, Infinite Bus Calculations, Transformer Calculation Worksheets.  In Class Problems – Short Circuit Calculations with Transformer Impedance

Theory of Motor Short Circuit Contribution, Sub-Transient Reactance, Xd”, Effect of Motor Contribution on Short Circuit Current, Multipliers for Motor Contribution.  In Class Problems – Consideration of Motor Contribution

Circuit Breaker and Fuse Interrupting Ratings, UL and ANSI Testing Methods, Symmetrical and Asymmetrical Short Circuit Current, Effect of X/R Ratio on Interrupting Ratings, Multiplying Factors when the X/R and Asymmetry are Too Large

Development of Series Ratings, Proper Application of Series Ratings, Dynamic Impedance, Fully Rated vs. Series Rated, Current Limitation, Let Thru Current, U.L. Tests

Short Circuit Study of Small Industrial System.  Calculations Include Source, Conductor and Transformer Impedance, Motor Contribution and Protective Device Adequacy Evaluation


Attend This Class to See How To:Power Distribution 1

 Perform Short Circuit Calculations
 Determine the Adequacy of Equipment
 Understand the Importance of Utility Data
 Understand why is the X/R ratio Important with Asymmetry
 Correctly Develop Series Ratings
 Calculate Short Circuit Motor Contribution
 Understand a Transformer’s Importance with Short Circuit Current

Receive Answers to These Questions and More

 What questions do I ask the utility company?
 What is the X/R ratio?
How does the X/R ratio effect a device’s interrupting rating?
What is motor contribution?
How do I calculate motor contribution on new systems with an undefined load?
• Is a short circuit study legally required?
What kind of data is required for the short circuit studies?
What if I can’t find all of the data, what assumptions can I make?
Why is the L/E ratio tm so important?
• How do current limiting fuses operate?
 What is a symmetrical current vs. asymmetrical current?
 How do I properly apply series ratings?


Brain LogoFor questions, registration information or to discuss holding this class at your location as an on-site training program, contact our Program Director at 800.874.8883

Brainfiller, Inc. | P.O. Box 12024 | Scottsdale, AZ 85267