Substation Technician how-to

How to Test a Protective Relay

Relay tests prove faults will clear.

Updated By the Career Education Institute Curriculum Team
Quick answer

Relay tests prove faults will clear. In short: review; isolate; connect, then complete the remaining steps below.

Step by step

  1. Review settings and schematics.

  2. Isolate trip outputs.

  3. Connect the relay test set.

  4. Inject test currents and voltages.

  5. Verify pickup and timing.

  6. Restore and document.

Safety reminders for substation technicians

  • Follow clearance and grounding procedures
  • Wear arc-flash PPE
  • Test before you touch
  • Maintain approach distances

Substation · Transformer · Circuit breaker · Protective relay · CT · PT: see the full substation technician glossary.

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