Rick Ashton’s Relay 101 Calculators

Rick Ashton has been passionately teaching people how to apply math to relay testing for decades and I was lucky enough to sit in on one of his relay classes. He was very generous with his expertise and had several free calculators on his relaytech.com website and inexpensive Ipad apps.

Rick retired and passed these calculators on to me so that his students could still use them. Here’s an introduction from the main page:

Welcome to RELAYS 101, the HTML version. Many of the topics covered in the three-day seminar and the copyrighted “RELAYS 101” lesson plan (and Apple Apps) are presented here. This is the final attempt at showing these topics in computerized formats to the future generations of protective relay technicians. In the 1990’s these topics were written and presented in Visual Basic Program (Windows) format and sold via website as “Relay Training Center Software”. In the 2010’s those same topics were rewritten for the iOS family and sold on the Apple App Store as “RELAYS 101” the App for iPhone and iPad. Now these topics are presented in the most uniformly accessible format to date: HTML. One can load all of the files in this bundle into a single directory on your laptop (or to a DVD or to a USB). Most any modern browser can read and display the HTML as a webpage. For the pages that have math operations one will note that “Javascript” is used. Anyone versed in basic HTML and basic Javascript can modify these web pages if desired. Specifically on the Relay Notes page, one can open the page and ADD your own relay testing notes into the appropriate “textarea”. If this technique is tried then be advised to use a simple text editor and save the file as simple text (with the file extension “HTML”). While a fancy word processor can be used, it is known that these applications may add specialized formatting codes that simply do not work well within HTML.

Here are some self-contained HTML pages that should work on most web browsers.

Different calculators that can help you step through the learning of many relay tech calculations.

You still have to think as a relay tech, these HTML applets don’t replace that.

Rick Ashton

Click the image below to use the calculators:

https://rick-ashton.b-cdn.net/RELAYS_101-HTML/RELAYS_101-HTML/RTC-INDEX.html

Here are all the calculators and their descriptions:

• Ohm’s Law – The Beginning – Z=V/I – Everyone’s electrical education begins with Ohm’s Law. This presentation is no different.
• Polar to Rectangular Conversions – Polar to Rectangular Conversions allows you to enter horizontal and vertical coordinates and convert them to the equivalent polar quantity.
• Power Triangle – Enter Watts and Vars values and calculate resultant Volt-Amps quantity. Or enter Volt-Amps quantity and calculate the value of the Watts and Vars
• Zp To Zs Conversions – Enter any three values (from Zp, Zs, CTR and PTR) and calculate the fourth quantity.
• Mho Math – Mho Math demonstrates the easy trigonometry used to predict the test values needed to produce a fault simulation that falls on the balance point (border) of a relay’s characteristic curve if that curve is a mho circle.
• Horizontal Characteristic – Horizontal Characteristic demonstrates the easy trigonometry used to predict the test values needed to produce a fault simulation that falls on the balance point (border) of a relay’s characteristic curve if that curve is a horizontal characteristic.
• Polar Plot On R-X Diagram – The R-X Diagram selection will let you enter Line Data and plot it on a quadrant diagram with a Mho Characteristic.
• Calculate Phase-Phase Values – The Phase-to-Phase Calculation selection will let you enter Phase-to-Neutral values and calculate the resultant Phase-to-Phase values.
• Subtract Vectors / Add Vectors – Subtract one vector from another in the first section. In the second section add up to eight vectors together (as might be necessary in a current differential scheme).
• Calculate Symmetrical Components – Enter 3-phase values of either voltage, current or impedance (magnitudes and angles) and calculate the symmetrical components of those three sets of values.
• B-C Fault with no V0 – Demonstration of the voltage and phase angle action during a B-C fault. There is no V0 in a phase-to-phase fault.
• Calculate K0 – Calculate K0 where K0 = (Z0-Z1)/3Z1. This is the calculation used by some, though not all protective relay manufacturers. GE for example has used K0 = Z0/Z1.
• In-Depth Instruction Learn K0 Calculation – Enter Line Impedance Data then predict the step-by-step values in the K0 calculation.
• In-Depth Instruction Learn Zero Sequence Calculation – Enter 3-Phase System Values then predict (step-by-step) and calculate Zero Sequence Values.
• In-Depth Instruction Learn Positive Sequence Calculation – Enter 3-Phase System Values then predict (step-by-step) and calculate Positive Sequence Values.
• In-Depth Instruction Learn Negative Sequence Calculation – Enter 3-Phase System Values then predict (step=by-step) and calculate Negative Sequence Values.
• In-Depth Instruction-Learn To Calculate Values For A Phase-Ground Relay Test – ZP-G = VP-G / IP-G It seems to be a bit complex but Ohm’s Law makes accurate distance relaying possible. Step-by-step calculations to create an A-G simulated fault for relay testing.
• In-Depth Instruction-Learn To Calculate Values For B-C Relay Test – ZP-P = VP-P / IP-P Ohm’s Law with specific voltages and currents to calculate specific impedances. Step-by-step calculations to create a B-C simulated fault for relay testing. Note that this calculation will more accurately reflect the phase-to-phase fault that has no I0 and no V0.
• In-Depth Instruction-Learn To Calculate Values For a 3-Phase Fault Relay Test – Z=V/I It’s like Ohm’s Law really does apply! Step-by-step calculations to create a 3-Phase simulated fault for relay testing.
• Relay Notes – General notes on relays and relay testing.
• SEL One-Bus – The SEL One-Bus selection takes you to a Javascript translation of the original BASIC Programming Language routine written by SEL and distributed in their early distance relay instruction manuals.
• Lecture Notes – Screen Shots of RELAYS 101 Lecture Notes
• Lecture Notes Bus Diff – Screen Shots of RELAYS 101 Lecture Notes
• Lecture Notes Assorted Calculations – Screen Shots of RELAYS 101 Lecture Notes

You can download them all at https://rick-ashton.b-cdn.net/RELAYS%20101-HTML.zip