html{display:none} SEL-4000 Relay Test System | Schweitzer Engineering Laboratories


Relay Test System

The SEL-4000 Relay Test System is designed for testing protective relays that have low-level test capabilities. The system consists of the SEL-AMS Adaptive Multichannel Source and either the SEL-5401 or SELtest software.

Starting At


Request a Follow-Up



Request a Follow-Up

Test two complete line terminals. Use the Adaptive Multichannel Source to provide the 3 voltage and 3 current waveforms to the relays for each end of a transmission line. Monitor the relay actions with the contact inputs, and simulate breaker 52a contacts with the contact outputs.

Test that your relay settings cause the relay to operate properly for a known condition. Set the relay, then playback event reports of known fault conditions to determine if the relay operates correctly.

Use amplitude ramping to test relay element thresholds.

Provide instantaneous and event report data, and simulate breaker operations in an informative demonstration for training, education, or other presentations.


Economical, Quiet, and Compact Adaptive Multichannel Source (AMS) Provides 12 Analog Outputs With 16-Bit Resolution
Test relays and other devices by simulating the waveforms from current or potential transformers, as presented to the internal analog input section of the devices under test. Using low-level analog signals reduces the cost, weight, power consumption, cooling, and noise of the test equipment that supplies high-level voltages and currents.

Digital I/O to Simulate Equipment and Monitor Test
The AMS includes six digital inputs to sense relay outputs and change test states. Use ten contact outputs to simulate station equipment, communications-assisted protection points, and more.

State-Simulation Software For Flexible Testing
The included SEL-5401 Test System Software provides a virtual front panel, plus multiple states to simulate power system changes and faults:

  • Sinusoidal outputs simulate steady-state conditions and changed-states.
  • Amplitude ramping supports relay element threshold tests.
  • Frequency ramping simulates system events and tests frequency elements.
  • COMTRADE files or Mathcad replayed through analog outputs.
  • Digital inputs can change state to simulate equipment or system event.
  • Digital outputs programmed for each state simulate communications and equipment contacts.

Complete Test Package
The AMS includes a 24/48/125 and 250 Vdc power supply, to power the equipment under test and the contact I/O. Cable harnesses for the equipment under test are included.

Order input power option of 110 Vac or 220 Vac.

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

Instruction Manuals

4000 - Software Tab

Supporting Software

SEL-5401 Test System Software

SEL-5401 software supports the SEL-4000 Relay Test System. It provides a virtual front panel and multiple states to simulate power system changes and faults.

Learn more and download on the Software Downloads page.