On successful completion of this course, delegates will understand how:
- To develop fundamentals & performance of LV, MV and HV switchgear.
- To provide methods and devise solutions for electrical problems encountered during connection and maintenance.
- To maintain a continuing understanding of tests carried out on circuit breakers ,and recording systems used in maintenance and troubleshooting of switchgear
- The design, functionality and failure modes of switchgear systems.
- To consolidate and update understanding of electrical safety during maintenance of switchgear systems.
Day 1: Introduction to Switchgear
- · Single line diagrams – what is a power network? Why different voltage levels?
- · Network components – active and passive – typical examples
- · Simple busbar and substation layouts – layouts – protection and control circuits
- · Fault Levels & MVA rating of equipment
- · Measuring transformers VT’s and CT’s
- · Circuit breaker utilization, disconnector operation and earthing switches
- · Fuses - LV and HV fuses. Fuse gear
- · Air break switches
- · MCC’s for LV distribution boards
- · Rating of switchgear - normal and fault duties
- · Selection and checking for correct switchgear ratings - LV, MV, HV and EHV
Day 2: Distribution Switchgear
- · Primary substations – name plate data
- · Device function numbers – suffix letters, main devices and auxiliary devices
- · Vacuum Switchgear up to 36kV
- · Description of equipment – front, rear, cable entry and busbars
- · Vacuum principles of interruption
- · Air and SF6 external insulation of busbars and vacuum interrupters
- · Oil breakers
- · Maintenance requirements air, oil, vacuum and SF6
Day 3: Switching, Safety and Earthing Requirements
- · Busbar configurations – single, double, sectionalized and breaker and a half
- · Main substation earthing and bonding
- · Step and touch potentials – danger to personnel
- · Routine testing and certification of substation earthing
- · Interrupter classification - mechanisms, motor - spring, hydraulic and solenoid
- ·Switching Requirements – interrupting time
- · Auto - reclosing considerations – ring main and radial circuits
Day 4: HV Gas Insulated Switchgear and Auxiliary Plant Maintenance
- · 145kV, 3 phase arrangement and single 275/400kV SF6 arrangements
- · Arc characteristics closing and opening – short circuit testing
- · Switchgear ancillaries, measurement CTs, VTs, relays
- · Decomposition of arced SF6 Handling contaminated materials – disposal!
- · Equipment required for maintenance – investigating leaks
- · Mechanism testing and auxiliary relay contact circuits – trip coils open/close
- · Contact trip timing tests and record interpretation – contact resistance tests
- · Fault recording and reporting – national data base of faults
- · Maintenance records
Day 5: Maintenance and Testing
- · Health and Safety in Substations
- · Mechanisms of deterioration of insulation
- · MCC testing and refurbishment - contacts and arc chutes
- · Trouble shooting – use of diagrams and manufacturers manuals
- · Block diagrams, line diagrams, wiring diagrams, interlock diagrams
- · Required maintenance – condition, heaters, fuses, mechanism, overhaul
- · Weekly, monthly, yearly program of maintenance – 5 years and more?
- · Principles of circuit breaker maintenance – mechanisms and mechanical aspects
Who Should Attend
This course is directed at anyone who would like to expand their knowledge of preventive maintenance of switchgear and protection of electrical networks.