The Complete Guide to the Square Root of Three in Power Calculations
Zach Stone, P.E. contacted me after I (Chris Werstiuk writing right now) posted my recent “Understanding the Great Leading vs. Lagging Power Debate” post because I had incorrectly defined Apparent Power. Thanks to his keen eye and knowledge on the subject, no-one who purchased The Relay Testing Handbook: Generator Relay
Understanding the Great Leading vs. Lagging Power Debate
I once watched two engineers/technicians argue for two hours about what power definitions should be displayed on a HMI interface. One of them argued that VARs were being EXPORTED during lagging conditions, so a lagging current should be shown as POSITIVE VARS and Power Factor! The other argued that VARs
Use Sequence Components To Make Sure Your Relay Isn’t Disabled By Incorrect Phase Rotation
Did you know that a relay connected to, or set with, the incorrect phase rotation can disable its higher level functions? Did you know that the wrong phase rotation can make your relay testing worthless? Did you know you can quickly and easily tell whether the phase rotation is correct
How to Perform an In-Service Protective Relay Meter Test
In-service protective relay meter tests are THE MOST important tests that should be performed on every digital relay. All of your offline relay testing is meaningless if: The CT/PT ratios are incorrect. The relay isn’t connected to its input signals (CTs/PTs). The relay is looking in the wrong direction. The
Why Does My Open-Delta Connected Phasor Diagram Look Weird?
Meter tests on protected relays connected to open-delta connected PTs can be very confusing. I know I spent a LOT of time trying to figure out the values reported by my first open-delta connected relay during my first simple meter test. The voltage and current phasors were completely out of
How to Understand and Determine Phase Rotation in a Power System
Understanding phase rotation is vital when connecting two systems together because the results can be catastrophic if someone doesn’t understand how to interpret phase rotation drawings. You would think something as important as phase rotation would have consistent terms across the entire industry. Unfortunately, you’d be wrong. Let’s start with