Pre-Commissioning Test Procedures for SEC Transmission Electrical Installations
Pre-Commissioning Test Procedures for SEC Transmission Electrical Installations
1. Introduction
The Saudi Electricity Company (SEC) requires rigorous pre-commissioning tests for transmission electrical installations to ensure system reliability, safety, and compliance with operational standards. Pre-commissioning tests are conducted before energization to verify the integrity and functionality of electrical equipment.
This document outlines the pre-commissioning test procedures for SEC transmission electrical installations, including transformers, circuit breakers, switchgear, protection relays, and SCADA systems.
2. Scope of Pre-Commissioning Testing
The pre-commissioning phase includes the inspection and testing of:
- Power Transformers (132kV, 380kV, etc.)
- Gas-Insulated Switchgear (GIS) & Air-Insulated Switchgear (AIS)
- Circuit Breakers & Disconnectors
- Current & Voltage Transformers (CTs & VTs)
- Protection and Control Systems
- SCADA, Telecommunication, and Auxiliary Systems
- Grounding & Earthing Systems
All tests comply with SEC standards, IEC 61850, and IEEE testing guidelines.
3. Pre-Commissioning Test Procedures
3.1 Visual Inspection & Verification
Before conducting electrical tests, a thorough visual inspection is carried out, including:
- Physical integrity of transformers, GIS, AIS, and switchgear
- Verification of nameplates, rating plates, and wiring diagrams
- Cable terminations, bolted connections, and insulation check
- SF6 gas pressure (for GIS) and transformer oil levels
- Earthing continuity and lightning protection
3.2 Transformer Pre-Commissioning Tests
- Insulation Resistance (IR) Test: Ensures transformer insulation health
- Turns Ratio (TTR) Test: Confirms voltage transformation ratio
- Vector Group Test: Ensures correct phase alignment
- Winding Resistance Measurement: Detects internal faults
- Magnetic Balance Test: Identifies core issues
- Oil Dielectric Strength Test: Ensures oil insulation quality
3.3 Circuit Breaker Testing
- Contact Resistance Measurement: Ensures minimal resistance in breaker contacts
- Timing Test: Measures opening/closing time to verify speed
- SF6 Gas Pressure Test (for GIS): Ensures adequate gas insulation
- Functional Test: Verifies tripping and closing operations
3.4 Current & Voltage Transformer Testing (CT & VT)
- Insulation Resistance Test
- CT Ratio & Polarity Test
- Excitation Curve Test
- Burden Test for CTs
- Secondary Injection Test for VTs
3.5 Protection Relay Testing
Using secondary injection kits (OMICRON, MEGGER, etc.), protection relays are tested:
- Overcurrent & Earth Fault Protection (OC/EF)
- Distance Protection (for Transmission Lines)
- Differential Protection (for Transformers & Busbars)
- Breaker Failure Protection
- Directional Overcurrent Protection (DOCP)
- Synchronization Checks
3.6 GIS / AIS Switchgear Testing
- High Voltage Withstand Test (HV Test)
- Primary Injection Test (for CT circuits)
- Busbar & Insulation Resistance Test
- Functional Interlock Verification
3.7 SCADA & Communication System Testing
- Remote Terminal Unit (RTU) Testing
- End-to-End Testing between Substations & Control Center
- Data Communication & Protocol Verification (IEC 61850, DNP3, etc.)
- Alarms, Indications, and Control Functionality Tests
3.8 Grounding & Earthing System Testing
- Continuity Test for Earthing Grid
- Earth Resistance Measurement
- Step & Touch Potential Testing
4. Test Equipment & Standards
The following test equipment is used for pre-commissioning:
- Insulation Tester (Megger 5kV, 10kV)
- OMICRON Relay Test Kit (CPC 100, CMC 356)
- Doble Power Factor Tester (Doble M4000)
- Transformer Turns Ratio (TTR) Tester
- Circuit Breaker Analyzer (Doble, Megger)
- Primary & Secondary Injection Kits
- SF6 Gas Analyzer
All tests follow SEC, IEC 61850, IEC 60270, and IEEE 400 standards.
5. Test Results & Documentation
After completing pre-commissioning tests, a comprehensive test report is prepared, including:
- Test procedures and observations
- Test results with pass/fail criteria
- Calibration certificates of test equipment
- Photographic evidence of test setups
- Recommendations for corrective actions (if needed)
6. Conclusion & Recommendations
The pre-commissioning tests ensure that all electrical installations in SEC transmission networks are safe, reliable, and ready for energization. Successful testing minimizes risks, prevents failures, and guarantees smooth grid integration.
Recommendations:
- Regular maintenance and periodic re-testing should be conducted
- SCADA and protection relay settings must be continuously monitored
- Spare parts and contingency plans should be available for critical components
This pre-commissioning test procedure is essential for compliance with SEC regulations and ensures a robust transmission system.