Electrical Substation Maintenance Course

Lesson 1 • Substation Types and Functions

Covers transmission, distribution, and switching substations and their roles in the power grid. Establishes the operational context for all subsequent maintenance tasks.

Lesson 2 • Electrical Safety Standards and PPE

Applies arc flash hazard analysis, approach boundaries, and required PPE selection for substation work. Directly supports safe execution of all hands-on maintenance activities.

Lesson 3 • Lockout/Tagout Procedures

Establishes energy isolation methods for de-energizing substation equipment before maintenance. Mastery of these procedures is a prerequisite for all practical lab sessions.

Lesson 4 • Core Electrical Principles Review

Reviews AC/DC theory, power factor, and three-phase systems relevant to substation operation. Provides the electrical vocabulary needed throughout the course.

Lesson 1 • Maintenance Records and Asset Management

Establishes standards for logging inspection findings, test results, and work orders in asset management systems. Accurate records enable trend analysis and regulatory audit readiness.

Lesson 2 • Visual Inspection Techniques

Teaches structured walkaround inspections for detecting physical defects on substation equipment. Builds observational discipline that underpins all condition-based maintenance decisions.

Lesson 3 • Oil and Fluid Sampling

Covers proper sampling procedures for transformer insulating oil and SF6 gas analysis. Links fluid condition data to transformer health assessment and maintenance prioritization.

Lesson 1 • Transformer Construction and Components

Examines core-and-coil assemblies, tap changers, bushings, conservators, and cooling systems. Component knowledge is essential for accurate fault diagnosis in later sections.

Lesson 2 • Dissolved Gas Analysis Interpretation

Interprets DGA results using key gas ratios to identify thermal and electrical faults inside transformers. Connects lab data to actionable maintenance or operational decisions.

Lesson 3 • Transformer Electrical Testing

Applies turns ratio, winding resistance, insulation resistance, and power factor tests to assess transformer condition. Test results guide maintenance decisions and establish baseline data.

Lesson 4 • Transformer Fault Diagnosis and Repair

Integrates test data, DGA results, and visual findings to diagnose and prioritize transformer repairs. Learners develop repair plans and assess return-to-service criteria.

Lesson 1 • Mechanical Inspection and Servicing

Covers operating mechanism inspection, lubrication, spring charging systems, and linkage adjustments. Mechanical reliability directly determines breaker response during fault clearing.

Lesson 2 • Contact Resistance and Timing Tests

Applies micro-ohmmeter contact resistance measurement and breaker timing analysis to assess contact condition. Results determine whether contacts require cleaning, adjustment, or replacement.

Lesson 3 • SF6 Gas Handling and Testing

Trains safe SF6 gas recovery, refilling, and purity testing in compliance with environmental handling standards. SF6 management is mandatory for all gas-insulated breaker maintenance.

Lesson 4 • Breaker Failure Analysis and Overhaul

Diagnoses common breaker failures including slow operation, restrikes, and contact erosion, then plans overhaul scope. Integrates all prior section skills into a complete maintenance workflow.

Lesson 1 • Protection System Fundamentals

Explains protection zones, relay coordination principles, and the role of instrument transformers in protection. Establishes the system-level context for individual relay testing tasks.

Lesson 2 • Protection Scheme Commissioning

Validates complete protection schemes including intertripping, auto-reclose, and busbar protection before energization. Commissioning confirms that all relay, CT, and wiring interactions perform as designed.

Lesson 3 • Numerical Relay Configuration and Testing

Configures settings, logic, and communication ports on microprocessor-based protective relays. Numerical relays dominate modern substations, making this section essential for current practice.

Lesson 4 • Secondary Injection Test Procedures

Performs secondary injection using test sets to verify relay operation without primary current injection. Covers test set connections, test plans, and pass/fail acceptance criteria.

Lesson 1 • Disconnect Switch Inspection and Servicing

Inspects blade alignment, contact surfaces, operating mechanisms, and interlock systems on disconnect switches. Reliable isolation depends on proper contact engagement and interlock function.

Lesson 2 • Busbar and Connection Maintenance

Addresses busbar cleaning, joint inspection, torque verification, and thermal cycling effects on connections. Loose or corroded connections are a primary source of substation failures.

Lesson 3 • Gas-Insulated Switchgear Maintenance

Applies GIS-specific inspection, SF6 density monitoring, and partial discharge testing procedures. GIS maintenance requires specialized techniques due to its sealed, pressurized construction.

Lesson 1 • Surge Arrester Inspection and Testing

Inspects and tests metal oxide surge arresters for leakage current, pollution, and physical damage. Functional arresters are the first line of defence against lightning and switching surges.

Lesson 2 • Earthing System Design Principles

Explains earth grid design objectives, step and touch potential limits, and soil resistivity effects. Design knowledge enables technicians to evaluate existing earthing adequacy.

Lesson 3 • Earth Resistance Testing Methods

Applies fall-of-potential, clamp-on, and staged fault methods to measure substation earth resistance. Accurate measurements confirm that the earthing system meets safety thresholds.

Lesson 4 • Lightning Protection System Maintenance

Maintains overhead earth wires, lightning masts, and down conductors that protect substation equipment. Verified lightning protection reduces equipment damage and outage frequency.

Lesson 1 • Maintenance Scheduling and Outage Planning

Develops maintenance schedules that balance equipment needs, outage windows, and operational constraints. Effective scheduling minimises grid impact while ensuring all assets receive timely service.

Lesson 2 • Maintenance Budget and Resource Justification

Builds cost-benefit cases for maintenance investments using life-cycle cost analysis and risk quantification. Financial justification skills enable technicians to advocate for necessary resources.

Lesson 3 • Key Performance Indicators for Maintenance

Defines and tracks KPIs including equipment availability, mean time between failures, and maintenance backlog. KPI monitoring enables data-driven programme improvements over time.

Lesson 4 • Reliability-Centred Maintenance Principles

Introduces RCM methodology, failure modes and effects analysis, and condition-based vs. time-based strategies. RCM provides the analytical framework for all maintenance programme decisions.