Sensor-to-Trip Functional Assurance Matrix

A requirements-to-evidence matrix for CT/VT, IED logic, communications, DC trip circuits, interlocking and breaker operation.

Printable checklist availableDownload the formatted A4 checklist with status boxes, evidence fields, project details and approval record.

Download PDF checklist A4 PDF · 2 pages

Create one row for every protection, control, alarm and interlocking function. The matrix links the design intent to its final witnessed evidence.

Recommended columns

  • Function ID and hazard or system requirement.
  • Initiating quantity or state.
  • CT/VT/LPIT source and polarity.
  • IED function, setting group and logic equation.
  • GOOSE/hardwired signal reference and supervision.
  • Output contact, trip relay, coil and breaker.
  • Expected alarm, indication, event and SCADA point.
  • FAT test case, SAT test case, result and evidence link.
  • Design owner, test owner, witness and approval status.

Minimum functional cases

  • Intended operation at the protection boundary.
  • Security for external or reverse faults.
  • Loss of VT, CT, sensor, communications, time and DC supply.
  • Local/remote and test/maintenance selector positions.
  • Breaker failure, lockout, intertrip and autoreclose interaction.
  • Alarm/event/SCADA mapping and timestamp quality.

Change control

Assign each row a settings, logic, drawing and SCL revision. A change to any dependency must identify which completed tests are invalidated and require repetition. Close the project only when every credited function has approved evidence or a formally accepted deviation.

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