html{display:none} SEL-T4287 Traveling-Wave Test System | Schweitzer Engineering Laboratories


Traveling-Wave Test System

The SEL-T4287 is a simple-to-use, compact, and economical secondary pulse injection test set for testing traveling-wave fault locators and line protective relays. Traveling-wave fault locators and protection elements and schemes measure sharp changes in their input currents and voltages with rise times as fast as 1 microsecond. The fault locators and relays respond to relative polarities and relative timing of these sharp signal changes. The SEL-T4287 generates output current signals with the short rise time, adequately slow decay, and nanosecond precision necessary for testing standalone traveling-wave fault locators, traveling-wave protective relays, and traveling-wave fault locators embedded in line protective relays.

Starting At


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  • Testing single-ended, double-ended, and multi-ended traveling-wave fault locators based on either currents or voltages.
  • Testing traveling-wave directional protection elements.
  • Testing traveling-wave current differential schemes.


    1. 1

      USB port for firmware upgrades

    2. 2

      View line and test parameters

    3. 3

      View the selected test trigger source

    4. 4

      Arm and initiate a test manually

    5. 5

      Navigate to line and test parameters

    6. 6

      Confirm new values of line and test parameters

    7. 7

      Change the menu selection, and dial in new values of line and test parameters

    8. 8

      Traveling-wave current outputs

    9. 9

      Initiate a test using a 48 V binary input trigger

    1. 1

      Transistor-transistor logic (TTL) cross-trigger outputs to other test sets

    2. 2

      TTL cross-trigger input from other test sets

    3. 3

      IRIG-B input from a satellite clock for synchronized testing

    4. 4

      Power supply: 110–240 Vac



Versatile Applications
The SEL-T4287 generates two 3-phase sets of secondary traveling-wave currents. An optional voltage module accessory (low-inductance resistors) allows you to convert one or both current output sets into traveling-wave voltage signals. Test current- or voltage-based fault locators or protection elements and schemes, including: single- and multi-ended fault locators, traveling-wave directional elements, and traveling-wave differential schemes. Time-synchronize or cross-trigger multiple SEL-T4287 sets to generate more than two three-phase traveling-wave signals with timing patterns as needed by the device under test. 

Simple Test Parameter Configuration
Specify line and fault parameters, and let the SEL-T4287 calculate and apply the traveling-wave test signals. A simple and intuitive SEL-T4287 human-machine interface (HMI) allows you to specify test parameters and offers full control of tests without the need for a PC and software. 

End-to-End Testing
Perform end-to-end testing of traveling-wave protection schemes and multi-ended fault locators with multiple SEL-T4287 test sets synchronized to satellite clocks via a standard IRIG-B input. Preconfigure each test set, schedule a test time, and let the multiple SEL-T4287 devices apply the right test signals at all terminals of the line. Test multi-ended traveling-wave fault locators for lines with more than two terminals. End-to-end testing is a standard feature included in the base price and can be used with any IEEE C37.118-compliant satellite clock with IRIG-B output.

The Firmware IDs for older versions of the firmware can typically be found in Appendix A of the instruction manual.

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