Standard Operating Procedures (SOPs) for GIS Substations You MUST Fully Respect

Substation SOPs and Safety

This technical article delves into the necessity of Standard Operating Procedures (SOPs) at GIS substations, emphasizing the importance of meticulous documentation, regular review, and formal approval processes to ensure that all operational activities adhere to safety and performance standards.

High-voltage (HV) substations are critical components of electrical power systems, serving as key points for transforming, regulating, and distributing electricity. Ensuring the safety and efficiency of operations in these complex environments requires a robust framework of Standard Operating Procedures (SOPs).

The initial sections highlight the need for SOPs at substations, detailing how proper documentation, thorough review, and official approval of procedures can mitigate risks and ensure consistency. Interlocking mechanisms, designed to prevent unsafe operations, are also discussed along with their limitations, underscoring the potential for human error and the severe consequences of such failures, including substation shutdowns and widespread power disruptions.

Subsequent sections focus on ensuring equipment safety during maintenance activities, outlining the critical steps of power cut-off, isolation, and earthing.

The article then transitions to the importance of aligning SOPs with international standards from organizations such as the International Electrotechnical Commission (IEC), Institute of Electrical and Electronics Engineers (IEEE)/American National Standards Institute (ANSI), and the National Examination Board in Occupational Safety and Health (NEBOSH). Compliance with these standards is essential for maintaining high safety and operational efficiency.

Finally, the article addresses the SOP for earth pits resistance testing, a critical procedure to ensure effective grounding at grid stations. This section outlines the scope, responsibilities, and standards involved, and provides a detailed method for testing and maintaining low resistance levels in earth pits, following IEC and IEEE guidelines.

By adhering to these comprehensive SOPs and international standards, substations can significantly enhance their safety, reliability, and operational efficiency, ultimately ensuring a stable and secure power supply.

Table of Contents:

1. Need for Standard Operating Procedures at Substations
   1. Importance of Documentation, Review, and Approval
   2. Interlocking Mechanisms and Their Limitations
   3. Ensuring Equipment Safety During Maintenance
2. Standard Operating Procedures at HV Substations: Compliance with IEC, IEEE/ANSI, and NEBOSH Standards
   1. Importance of Standards in SOPs
   2. Relevant Standards:
      1. IEC Standards
      2. IEEE/ANSI Standards
      3. NEBOSH Standards
3. Implementing SOPs in Compliance with Standards
   1. Documentation and Review
   2. Training and Certification
   3. Safety Protocols
4. Standard Operating Procedure for Isolation and Maintenance of a 132kV GIS Line Bay
   1. Isolation Procedure for 132kV GIS Line Bay:
      1. Coordination and Permit Issuance
      2. Informing the Shift Engineer
      3. Ensuring Line De-energization
      4. Isolating the Line Bay
      5. Starting Maintenance Activities
   2. Restoration of the System:
      1. Completion and Coordination
      2. Safety Measures
      3. Restoring Connections
5. Standard Operating Procedure for Earth Pits Resistance Testing
   1. Scope
   2. Standards and References
   3. Procedure:
      1. Understanding Earth Electrodes
      2. Importance of Low Resistance
      3. Preparation for Testing
      4. Methods of Measuring Earth Electrode Resistance
      5. Conducting the Test
      6. Recording and Analyzing Results
      7. Reconnecting the Earth Electrode
      8. Reporting and Documentation
6. BONUS (PDF) 🔗 Download SOP Documents for 132kV GIS:
   1. SOP for 132KV Trafo Line Bay Isolation & Restoration (PDF)
   2. SOP for 132kV Grid Line Isolation & Restoration (PDF)
   3. SOP for Line Trip and Restoration (PDF)

1. Need for Standard Operating Procedures at Substations

Standard Operating Procedures (SOPs) are critical for ensuring safe and efficient operations at high-voltage (HV) substations. Given the complexity and high-risk environment of substations, SOPs provide a structured framework for documenting, reviewing, and approving all operational activities.

This ensures that every procedure is performed correctly, consistently, and safely.

1.1 Importance of Documentation, Review, and Approval

When a substation is live, any operation or activity must be carefully planned and executed. This involves:

1. Documentation: Detailed records of procedures ensure that all steps are followed precisely. This includes instructions for routine maintenance, emergency responses, and operational switches.
2. Review: Procedures must be reviewed regularly to ensure they comply with current standards and safety regulations. This review process helps identify potential risks and mitigate them before they become issues.
3. Approval: Every procedure must be approved by a qualified authority. This step ensures that all safety protocols are in place and that the procedure aligns with operational goals and regulatory requirements.

Figure 1 – Single Line Diagram and Interlocking Scheme for 132 GIS

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1.2 Interlocking Mechanisms and Their Limitations

Electrical equipment at substations is often interlocked to prevent dangerous operations. For example, an earth switch cannot be closed if the relevant isolator is not already in the correct position.

These interlocking mechanisms are crucial for preventing human error and ensuring safety.

Such errors can lead to catastrophic consequences, including:

1. Substation Shutdown: The immediate substation can be taken offline, interrupting the power supply to a significant area.
2. Power Swing and Cascade Tripping: The initial fault can cause a power swing, leading to cascade tripping across the network. This can result in widespread blackouts, potentially affecting entire regions or countries.

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1.3 Ensuring Equipment Safety During Maintenance

For maintenance activities, it is crucial to ensure that the equipment is safely de-energized. This involves:

1. Power Cut-Off: Isolating the equipment from the power source to prevent accidental energization.
2. Isolation: Physically separating the equipment from the live parts of the system.
3. Earthing: Connecting the isolated equipment to the ground to discharge any residual electricity and provide a safe work environment.

By following these steps, maintenance personnel can safely perform their tasks without the risk of electrical accidents.

Implementing and following SOPs rigorously can significantly reduce the risk of accidents and improve the reliability of power systems.

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2. Standard Operating Procedures at HV Substations

Compliance with IEC, IEEE/ANSI, and NEBOSH Standards

Standard Operating Procedures (SOPs) at high-voltage (HV) substations are vital for ensuring operational safety and efficiency. Adhering to relevant international standards, such as those from the International Electrotechnical Commission (IEC), Institute of Electrical and Electronics Engineers (IEEE) / American National Standards Institute (ANSI), and the National Examination Board in Occupational Safety and Health (NEBOSH), is essential for maintaining high safety and performance levels.

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2.1 Importance of Standards in SOPs

Standards provide a framework for developing, implementing, and maintaining effective SOPs. They ensure that procedures align with best practices, legal requirements, and safety guidelines.

This alignment helps mitigate risks, improve reliability, and ensure the safety of personnel and equipment.

Relevant Standards:

IEC Standards

• IEC 61850: This standard deals with communication networks and systems in substations. It provides guidelines for interoperability and ensures reliable and efficient communication between substation devices.
• IEC 60255: Focuses on measuring relays and protection equipment, providing guidelines for their performance and testing to ensure reliability in protective systems.
• IEC 62271: Covers high-voltage switchgear and control gear. It includes specifications for various components and systems, ensuring they meet safety and performance criteria.

Suggested Reading – Functional testing of IEC 61850 based SAS

Functional testing of IEC 61850 based Substation Automation Systems

IEEE/ANSI Standards

• IEEE C37.2: Standard for electrical power system device function numbers, acronyms, and contact designations. It helps in the consistent identification and operation of protective devices in substations.
• IEEE 1584: Provides guidelines for arc flash hazard calculations. This standard helps in assessing risks and implementing safety measures to protect personnel from arc flash incidents.
• ANSI/IEEE C37.100: Covers definitions and requirements for switchgear assemblies. It ensures that equipment used in substations meets performance and safety standards.

Suggested Reading – Prepare yourself for successful inspection and testing of MV metal-clad switchgear

Prepare yourself for successful inspection and testing of MV metal-clad switchgear

NEBOSH Standards

• NEBOSH General Certificate: While not a standard per se, the NEBOSH General Certificate provides comprehensive training on occupational health and safety. It ensures that personnel are aware of the hazards and safety practices relevant to HV substations.
• NEBOSH International Diploma: Offers advanced knowledge in health and safety management, preparing professionals to implement and maintain effective safety systems in high-risk environments like substations.

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3. Implementing SOPs in Compliance with Standards

3.1 Documentation and Review

SOPs should be meticulously documented, reviewed, and updated to comply with IEC, IEEE/ANSI, and NEBOSH standards.

This includes:

1. Detailing the procedures for operating, maintaining, and inspecting GIS substation equipment.
2. Conducting regular reviews to ensure SOPs reflect the latest standards and best practices.
3. Involving qualified personnel in the review and approval process to ensure compliance and relevance.