Category Archives for Relay Elements
A New Transmission Line Protection (21) Video
End-to-End Testing can appear to be a daunting task. However, any relay tester can perform successful End-to-End Tests with a basic understanding of transmission line protection (or 21 impedance protection)
Continue readingFinding the Direction in Directional Overcurrent Relays
A reader recently asked a question about the forward and reverse directions described in the Directional Overcurrent Relay section of The Relay Testing Handbook series. I used electro-mechanical directional
Continue readingDistance or Impedance Protection (21) Video
Line distance (21) protection is primarily used to protect transmission lines or other electrical equipment where the equipment’s impedance characteristic can be calculated or modeled with software
Continue readingGood Directional Overcurrent Protection (67) Video
Instantaneous overcurrent (50) and time overcurrent (51) protection can protect equipment from overloads and short circuits, but there are situations where their ability to protect a system is limited.
Continue readingTesting Basler BE1-47N Negative Sequence Voltage Relays
Testing more complicated elements that use a percentage or ratio between values can be difficult if you cannot properly define all of the values in the equation. It doesn’t help that different
Continue readingReal World Problem With an SEL-300G Synch-Check
Here is a story from one of our Customers at Manta Test Systems: “I had to troubleshoot a Schweitzer SEL-300G relay yesterday that had the (25) Sync-Check element enabled, but wouldn’t assert the
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