RELAYS 101 Three-Day Protective Relay Technician Training


"RELAYS 101" Three-Day Relay Training Center Seminar at your USA training site

- forget it, I'm retiring. You missed out!

If you want our seminar presented at your USA training site then contact us for available training dates.

Get your company on the committed list soon, available dates in 2019 are nearly gone.

First come, first served.

Do you think your math skills need work?

The math used in this class is high school level Trigonometry.

We only spend about an hour at the beginning of the first day of class on the basic Trigonometry used in the class so refresh your skills with this downloadable worksheet.

The worksheet is not an example of the simple topics presented in "Relays 101". Instead the worksheet shows examples of the simple math used in this seminar.


Embrace the simple math concepts needed to better understand your protective relays.

The Relay Training Center Seminar is conducted at your USA training facilities. Your cost per student goes way down when you have a lot of technicians to train and the training takes place at your site. Your technicians have minimal travel and you can get all up to speed with "RELAYS 101". One price covers all students. The only limitation to the number of students is the number that can be supported by your own training facilities. We ask that the students bring their Trig-function calculators.

Contact us for a price quote.

The Relay Training Center Seminar can be configured to meet your needs but, our success at creating protective relay technicians with our standard lesson plan is unmatched in the business. We do not seek to teach your technicians the nuts and bolts of operating your particular brand of test equipment, (you can get that from your equipment vendor).

Instead we will provide you with topics that help illustrate the fundamentals of how the power system works.

With no more prerequisite training than high school level Trigonometry, Ohms Law and an introduction to protective relay testing we turn out technicians with added power system knowledge and new relay testing abilities and confidence. 

Many of our utility clients have brought us back for repeat presentations because this is the training that they had needed all along. We have clients that have our presentation of "RELAYS 101" as a part of their internal technician training program. Many technicians seek refresher training as some of these concepts are not things that are used routinely so refresh training helps conceptual understanding and retention.


The goal of every seminar is that the relay technicians have an understanding of the calculation of symmetrical components.

By the end of the class we will have reviewed the high school level Trigonometry that is used to calculate the sequence components. The student will learn how to calculate these component values and use them in the world of protective relay testing.

The student will know the rules by which the sequence components operate.

In short, the mystery of symmetrical components is removed.

The technician will have the understanding of symmetrical components needed to use them in testing protective relays.

If you have an IEEE device #46 or #47 relay then you need this knowledge!

The Symmetrical Components presentation is geared toward demonstrating the ease of testing one of the most complex protective relays that a protective relay test technician faces (the Negative Sequence Overcurrent Relay - Device #46).

As you can see from the sample test, there are many topics covered in the RTC Seminar.

The discussions on Symmetrical Components cover only about 4 hours of the three-day seminar!

It is fast paced because we want to give you the best opportunity to grab the training on all of the topics in one class. We could split the training in two but we understand how hard it is to find the time to train your technicians when they also have work to get done.

If you can answer only a few questions correctly now, you will be surprised how well you do on this test AT THE END OF THE THREE DAYS!

Please do not mis-understand this test. If you can pass this test then you probably do not need this course. But, we have had enormous success, since 1999, bringing complex topics into the technician arena in a manner that can be understood by non-engineers.


Do you sometimes feel like a protective relay caveman?

Are you merely following a pre-printed recipe of relay tests?

Would you rather understand what you are doing?


Check out the typical list of topics covered in our 3-day seminar: 

RELAYS 101 is an intense three (3) days course, eight (8) hours per day that covers the following curriculum: 

  • Applying Trig Functions to the World of Relays - 1 hour
    • Trig Functions used for meter and relay calculations 
    • Law of Sines used to find the boundary of a Lens Characteristic 
    • Law of Cosines used to find “Delta-V” in Sync Check Relays 
  • Introduction to Basic Logic Functions / 1 hour
    • AND Gate and its equivalent DC Circuit 
    • OR Gate and its equivalent circuit 
    • NOT Gate and its equivalent circuit 
  • Discovering Transformers / 2 hours
    • Discovering the polarity of transformers 
    • Discovering Current Transformers 
    • Discovering that VA of transformers is the same on HV and LV sides 
    • 87T relay schemes need to compensate for equal VA on both sides of the transformer 
    • Delta-Y or Y-Delta transformers have a 30 degree shift, where does it come from? 
    • 87T relay schemes need to compensate for that 30 degree shift. 
  • Quadrant Diagrams, Math Operators and Directionality / 1 hour
    • When to use X-Y Diagrams 
    • When to use R-X Diagrams 
    • When to use P-Q Diagrams 
    • Discussion of Power System Events and Faults 
  • Converting Values for Relay Tests / 1 hour
    • Primary Ohms to Secondary Ohms conversion 
    • Polar Coordinates to Rectangular Coordinates conversions 
  • Reactance Changes Everything! / 2 hours
    • Watts Calculation 
    • VARS Calculation (What is a VAR anyway?) 
    • Line Angle and Power Factor 
    • Line Constants, Operating Quantities, Angle of Max Torque and Operating Characteristics 
  • Calculating Phase-to-Phase Values / 4 hours
    • Step Distance Concept 
    • Errors in Protection Systems 
    • When to use the square root of three (and when NOT to) 
    • Calculate any phase-to-phase value (without the square root of three) 
  • Calculating Symmetrical Components / 4 hours
    • Positive Sequence Calculation 
    • Negative Sequence Calculation 
    • Zero Sequence Calculation 
    • Fuse Failure / Loss of Potential circuits 
    • Forcing neutral current 
    • Directional units 
    • Zero Sequence detector circuits 
  • Calculating Apparent Fault Impedance / 2 hours
    • Phase-to-phase fault calculation 
    • Introduction to Zero Sequence Compensation Factor 
    • Phase-to-ground fault calculation 
    • 3-phase fault calculation 
  • Impedance Plots / 2 hours
    • Draw load vectors or fault vectors on X-Y Diagram 
    • Perform the math from Ohm’s Law 
    • Draw load Z or fault Z plot on R-X Diagram
  • Views of a Fault / 2 hours
    • Phase vectors on X-Y Diagram 
    • Impedance plots on R-X Diagram 
    • Symmetrical Component vector comparisons 
    • Sine waves can be examined 
    • Harmonics can be examined 
  • Relays By The Numbers / 2 hours
    • Relays by IEEE Device Number 
    • Discussion of Mho Circles and testing Device 21 relay 
    • Discussion of 87T tests 
    • Discussion of generic testing requirements for other relays by IEEE Device Number 
    • Discussion of NERC PRC 5 requirements of Microprocessor relays 

As you can see from this schedule, this is a very intense seminar. Some repeat clients have requested special changes to this seminar to add more time on some topics. Most repeat clients simply like the 3-day format as it works well with the production work-week. 

The last part of the class, known as "Relays By The Numbers", is intended to take some of the mystery out of relay testing.

The discussion centers around relays by device number NOT by manufacture; all protective relays have to function in the same power system using the same physics. So, it follows that the testing should be the same for all relays regardless of manufacture or vintage.

The topics are about how and why the relays respond to quantities. The student can always follow through, back home, with the individual relay instruction material to decide upon particular hook-ups and adjustments. But, the training learned here will ensure that the right tests are run.

In addition to this RELAYS 101 seminar we also have Relays By The Numbers hands-on training available.

RTC (sm), Relay Training Center,, the content on this website, Relays 101 (C) the seminar, RELAYS 101 and Relay Tests the iOS Apps are all owned, maintained and copyrighted by Merle E. Ashton.