Class 4 of 8: Overcurrent Protection (50/51/50N/51N/51G) and Time-Current Curves. This self-paced class covers 50 and 51 elements, multiples of pickup, time dial, IEEE C37.112 inverse curves, 50N/51N and 50G/51G ground connections, and reading time-current curves, inrush points, damage curves and CTI, plus a field walkthrough and a case study. It has about 45 minutes of lesson content plus activities and a 30-question quiz. It is part of the SubstationU.com Protective Relaying Series (Level 1 course). Continuing education credit: 0 (none awarded yet).
Read the lesson book and complete the video activities, then pass the 30-question quiz with 80% (24 of 30) or better; you can retake the quiz as many times as you need until you pass. Each of the eight classes is a separate course, and the recommended order is Class 1 to Class 8, but you can take them in any order.