Jeffrey Brown reached out to help announce his new book, Power Line Carriers – Simplified: A Field Engineer’s Perspective I don’t know much about power line carrier. I’ve only
Continue readingWe covered the basic operating principles of high impedance busbar differential protection in our previous post, I Want to Know How a High Impedance Differential Scheme Works. You should read that post
Continue readingWe received this question from the Ask Chris form at relaytraining.com. Follow this link to ask your own question and it might appear in a future blog post. High Impedance Differential Scheme Testing High
Continue readingI was recently asked about DC Offset during a paper I presented at the 2015 Hands-On Relay School and struggled with an answer because I know what it looks like and I know it exists, but I’ve never heard
Continue readingHere is a question submitted to the Ask Chris section of the RelayTraining.com website about the best path for electrical employment. I have just recently completed an IBEW apprenticeship and tested out
Continue readingRahim submitted this question to the Ask Chris section of the RelayTraining.com website. Most line distance protection schemes assume that the system will always be able to supply enough amps to make the
Continue readingThis question was submitted via the Ask Chris form where you can ask me relay testing questions that I can hopefully answer. Creating test plans for digital relays is often difficult because you can have
Continue readingIn the previous post about Directional Overcurrent relay (67) testing (Finding the Direction in Directional Overcurrent Relays), we reviewed Directional Overcurrent protection from a system perspective
Continue readingA reader submitted a question through the Ask Chris form. I’ve expanded the original question from “what are the differences between relays, contactors and motor starters?” to “What
Continue readingSituation after CT Primary Injection: New 230kv breaker Testing CT’s, 4000/5, by high current injection injecting 80 amps A phase to ground the secondary leads are shorted in a junction box A-B-C-N
Continue readingA 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 readingSEL 321 OSB upper tests fine, lower is no-op but 51g comes in any ideas? I’m oversight on a project, test company is using a Doble 6150 w/ RTS, I’m not very familair with RTS sdg
Continue readingI am writing to enquire about 67N test procedures, specifically Schweitzer relays. The Page 94 of the Relay Testing Handbook #C2 : Practical Relay Testing (50/51/67/59/27/81/87/21) by Chris Werstiuk says
Continue readingI can not find up dated information on this relay. I am testing with a manta 5000. I put 60 vac 60 hz on leads 7 and 8 and the relay picks up. Then on lead 11 & 12 I put 180 Hz and bring up vac to
Continue readingTo all, We had a SBF-1 Breaker Failure Relay fail on us yesterday. The time delay was not working properly. We have many of these relays on our system and wanted to see if there has been a Relay Advisory,
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