Relays

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Protection Relay Testing & Commissioning
Accuracy That Saves Equipment

In modern power systems, protection relays are the brain behind circuit breaker operation. They monitor electrical parameters, detect abnormal conditions, and trigger breakers to isolate faults—often within milliseconds.

If a relay fails: Equipment damage worth crores, extended power outages, and safety hazards for operating personnel.
Our Testing Process Get Quote

Types of Relays We Test & Commission

Electromechanical, static, and numerical relays for power systems 11 kV to 400 kV

Electromechanical Relays

Use: Legacy protection in older installations

Focus Areas:
  • Mechanical calibration
  • Contact wear assessment
  • Pickup/dropout values verification
  • Operating coil condition

Static (Solid-State) Relays

Use: Mid-generation technology, analog components

Focus Areas:
  • Threshold accuracy verification
  • Component health assessment
  • Trip timing precision
  • Temperature stability

Numerical (Microprocessor) Relays

Use: Modern protection for AIS and GIS substations

Focus Areas:
  • Software configuration validation
  • Communication protocol integration
  • Self-diagnostics verification
  • IEC 61850 compliance

Why Relay Testing is Critical

Avoids False Trips

Prevents unnecessary outages that cost revenue and reputation

Prevents Non-Operation

Ensures faults are cleared before damage spreads

Regulatory Compliance

Meets CEA, IS, IEC, IEEE standards

Supports Coordination

Works seamlessly with CTs, PTs, and breakers

Improves Asset Life

Protects transformers, lines, and switchgear from fault damage

Millisecond Response

Ensures rapid fault isolation to minimize equipment damage

Our Relay Testing & Commissioning Process

Comprehensive testing per IS 8686, IEC 60255, IEEE C37 standards

1. Pre-Commissioning Checks

Model & Firmware Verification:

Confirming relay type and version matches system design

Wiring Verification:

CT/PT secondary connections, trip circuits, auxiliary supplies

Setting Review:

Cross-checking pickup values against coordination studies

2. Electrical & Functional Testing

Insulation Resistance Test
Between input/output circuits and earth
Contact Resistance Test
Low resistance for effective breaker triggering
Pickup & Dropout Testing
Correct current/voltage thresholds and reset values
Time-Current Characteristic
Confirms tripping times match specified curves
Secondary Injection Testing
Simulated signals directly into relay inputs
Communication Protocol Testing
IEC 61850, Modbus, DNP3 for SCADA integration

3. Integration with Protection Scheme

  • Breaker Coordination: Confirming breaker trips within specified time
  • Interlock Testing: Verifying interlocks with other relays and control logic
  • SCADA/EMS Integration: Real-time relay data visibility to operators

4. Commissioning Procedure

  • Apply controlled energization to system
  • Simulate various fault scenarios (overcurrent, earth fault, differential, distance)
  • Verify tripping accuracy and event recording
  • Submit detailed reports, setting files, and certificates

Real-World Example

Numerical Relay Commissioning for 220 kV Substation in Gujarat

Multi-Protocol Integration

220 kV Substation, Gujarat - 2024

Project Highlights

Relay Types: Overcurrent, differential, and distance protection relays

Challenge: Mixed vendor equipment and multi-protocol SCADA integration

Solution: Custom configuration using IEC 61850 GOOSE messaging for fast trip signaling

3 Days

Ahead of schedule completion

Zero Errors

Integration without faults

Industry Trends in Relay Testing & Commissioning

Adaptive Relays

Real-time adjustment of settings based on system conditions

Digital Substations

Full IEC 61850 integration replacing hardwired connections

Remote Testing

Cloud-based relay setting management and diagnostics

Cybersecurity

Hardening numerical relay communications