ELC 309

Medium & High Voltage (MV/HV) Switchgear (Operation, Maintenance & Safety Practices)

This specialized hands-on course is designed to provide engineers and technicians with in-depth knowledge of medium- and high-voltage switchgear systems used in power generation, transmission, distribution, and large industrial installations.The program focuses on the operation, inspection, maintenance, safety procedures, fault handling, and reliability of MV/HV switchgear, with strong emphasis on personnel safety, asset protection, and compliance with industry standards.Participants will gain practical understanding of switchgear construction, protection principles, operational procedures, and maintenance best practices required for safe and reliable MV/HV system operation.

Duration: 5 days

Prerequisites: Strong knowledge of electrical fundamentalsExperience with industrial electrical systemsBasic understanding of power distribution systemsPrior completion of ELC 307 is an advantage

Course objectives

Understand MV/HV switchgear construction and operating principles
Safely operate medium- and high-voltage switchgear
Apply standard switching and isolation procedures
Perform routine inspection and maintenance tasks
Identify and respond to MV/HV switchgear faults
Apply electrical safety and arc-flash mitigation practices
Improve switchgear reliability and service life
Maintain proper operational and maintenance documentation
By the end of this course, participants will be able to:

Course content

Day 1 MV/HV Switchgear Fundamentals & Safety Principles

Overview of MV/HV power systems
Classification of switchgear:
Air-insulated switchgear (AIS)
Gas-insulated switchgear (GIS)
Vacuum circuit breakers
Oil and SF₆ insulation concepts
Switchgear components:
Circuit breakers
Isolators and earthing switches
Busbars and compartments
Protection relays and interlocks
High-voltage safety principles and PPE

Hands-On Practical:

Identify MV/HV switchgear components
Review switchgear layouts and single-line diagrams
Practice safety briefing and PPE selection
Understand access and interlock systems

Day 2 Switchgear Operation & Switching Procedures

Normal operating procedures
Switching sequences for:
Energizing and de-energizing feeders
Transformer switching
Load transfer operations
Interlocking and permissive logic
Earthing and isolation procedures
Operational documentation and logs

Hands-On Practical:

Simulate switching operations using models or simulators
Practice correct isolation and earthing steps
Follow standard operating procedures (SOPs)
Record switching activities correctly

Day 3 Maintenance & Inspection of MV/HV Switchgear

Maintenance philosophies for MV/HV equipment
Routine inspection and condition checks
Mechanical inspection:
Operating mechanisms
Contacts and linkages
Electrical inspection:
Insulation condition
Contact resistance
SF₆ gas pressure and quality (if applicable)
Testing methods:
Insulation resistance
Contact resistance measurement
Timing tests

Hands-On Practical:

Perform visual and mechanical inspections
Conduct basic electrical tests on switchgear components
Check interlocks and protection devices
Document inspection findings

Day 4 Fault Handling, Protection & Reliability

Common MV/HV switchgear faults:
Insulation failure
Contact wear and overheating
Mechanical malfunction
Protection principles and coordination
Arc flash causes and mitigation techniques
Fault response and emergency procedures
Reliability and asset life management

Hands-On Practical:

Analyze switchgear fault case studies
Simulate protection trips and fault conditions
Practice emergency response procedures
Review reliability improvement measures

Day 5 Safety Management, Compliance & Final Project

Safety management systems for MV/HV operations
Permit-to-work and switching authorization
Standards and regulations overview (IEC / IEEE)
Maintenance documentation and audits
Asset records and lifecycle management
Real-world MV/HV switchgear case studies

Hands-On Practical:

Execute a complete switching and isolation exercise
Perform inspection and maintenance planning
Apply safety documentation procedures
Final practical assessment and review