APP T400L: SEL-T400L Time-Domain Line Protection

Course Length: 3 Days (PDHs: 23)
Course Based Fees: $1,500*
* Plus Applicable Tax


APP T400L covers traveling-wave protection concepts with hands-on application where you will learn about the SEL-T400L Time-Domain Line Protection relay’s protection and fault-locating functions. You will also complete hands-on exercises to configure, set, and test the relay.


This course is intended for utility transmission protection engineers, electrical technicians, and power system consultants who want to understand the protection principles, logic, and testing of the new SEL-T400L in detail.


Day 1

  • Introduction
  • SEL-T400L Overview
  • Setting Guidelines
  • Example One-Line Diagram and Parameters: Two-Terminal, 525 kV Line
  • Hands-On Exercise: Configuring the SEL-T400L Relay and Calculating and Applying Settings
  • Arming, Starting, and Fault-Type Identification Logic
  • Introduction to Incremental Quantities
  • TD32 Directional Element Logic

Day 2

  • TD21 Incremental-Quantity Distance Element
  • Overcurrent Supervision Elements
  • Testing and Commissioning Incremental-Quantity Elements TD21 and TD32 (includes hands-on exercise)
  • Introduction to Traveling Waves
  • TW32 Directional Element
  • Testing Traveling-Wave Directional Element (includes hands-on exercise)

Day 3

  • TW87 Scheme Logic
  • Testing the Traveling-Wave Differential Scheme (includes hands-on exercise)
  • POTT, DTT, and Trip Logic
  • Fault-Locating Methods
  • Event Analysis Using synchroWAVe Event Software
  • Hands-On Exercise: Configuring the SEL-T400L for Single-Pole Tripping, Reclose Initiate, and Breaker Failure Initiate

Learning Outcomes

At the conclusion of this course, students can:

  • Apply the SEL-T400L time-domain protection elements.
  • Explain the SEL-T400L signal processing.
  • Configure the SEL-T400L incremental-quantity protection elements.
  • Configure the SEL-T400L traveling-wave protection elements.
  • Calculate, apply, and test settings for the SEL-T400L.
  • Configure the SEL-T400L traveling-wave fault-locating function.

Student Background and Knowledge

Before you attend this class, we recommend that you complete CBT 101: Introduction to SEL Relays.

Course Preparation

Install or update the following software/files on the laptop you are bringing to class:

In addition, please make sure that your laptop has an Ethernet port.

Please ensure that your laptop does not have any installation blocks before you come to class.

Additional information is on the Course Policies and FAQ pages.

Available Courses

Request onsite training for your company.