html{display:none} CBT 104: Understanding SEL Relay Logic | Schweitzer Engineering Laboratories

CBT 104: Understanding SEL Relay Logic


This course is intended for engineers, technicians, and consultants new to SEL relays or logic programming.

Confused by logic diagrams and SELogic control equation settings? Need to be able to test relay logic before it goes in service? In CBT 104, you will learn how to read, set, and test SEL relay logic as you identify Relay Word bits and SELogic operators, and visually interpret diagrams. Learn to equate relay protection functions with logic diagrams, and see how relay logic assigns protective elements to output contacts for control, monitor, and trip functions.

This course is designed as a half-day program but is self-paced.


  • Introduction
  • Relay Logic Basics
  • Visualizing Logic
  • Settings and Logic
  • Testing Relay Logic
  • Event Analysis and Logic
  • Knowledge Check

Course Objectives

At the conclusion of this course, students can:

  • Correlate Relay Word bits with settings and protection functions
  • Visually identify logic components
  • Differentiate between settings and logic
  • Analyze logic diagrams
  • Interpret logic using a relaying schematic
  • Use acSELerator QuickSet SEL-5030 Software to convert and visualize logic
  • Diagnose problems using event data and logic
Course Information

Single-User Training

Course Base Fees: $USD350*

CBT licenses will expire one year from the purchase date. CBT 101 is a lifetime license.

CEUs: 0.4
Average Completion: 4 hours
Available Courses
Single-User Training

SELU Training Question


Course Requirements


Students should have a basic knowledge of power systems.

Course Preparation

Check the General Course Information page for course preparation details.