Beginners Level for Technicians

A must for technicians who are setting out to build a career in relay testing. This course has all the basics to propel you forward and prepare you with the tools and techniques you need. Register now to arm yourself.



Day 1

Introduction to Protection
Basic Trigonometry
Converting rectangular to polar form
Three Phase Connections
Reading single line, three line diagrams
AC/DC Schematics
Reading time overcurrent curves

Calculation of

  1. Volt Amps
  2. Watts
  3. Inductive Vars
  4. Capacitive vars
  5. Power Factor
  6. Power Triangle
  7. Maximum Torque Angle

Transformer Basics
Phase shifts in transformers
Current transformers (including polarities)
Voltage transformers
Connections of CTs and PTs
Converting primary ohms to secondary ohms
R-X diagrams


  1. Three phase
  2. Phase-Phase
  3. Phase-to-ground

Phasor diagrams for each type of fault
Hands on exercises

Day 2

Symmetrical Components-Simplified
Hands on exercises
Introduction to Protective Relays
Device numbers
Different types of protective relays
Basics of Electromechanical relays
Basics of solid state relays
Basics of microprocessor relays
Logic diagrams used in microprocessor relays

Types of tests

  1. Steady State Testing
  2. Dynamic Testing
  3. Transient Testing

Various methods of communication used with relays and test sets
F6150 Test Set
Hands on use of test set
Brief overview of Protection Suite (Doble Testing software)

Day 3

Description of different relays and testing procedure

  1. Overcurrent
  2. Directional Overcurrent
  3. Distance relays
  4. Differential
  5. Sync Check
  6. Over under voltage
  7. Timers
  8. Transducers

Dates and Locations

This course is scheduled for the following dates at the Doble facilities in Morrisville, North Carolina.

  • August 4-6, 2020
  • October 13-15, 2020

Doble Engineering Company
2200 Gateway Center Blvd, Suite 207
Morrisville, NC 27560

Registration Fee

The cost to attend this course is $1400 USD per student. Minimum of 8 students are required for this course to be conducted.

Continuing Education

NETA CTDs can be applied for by presenting to NETA a certificate of course completion. CEUs are available.