Outlines

 

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.

Duration

5 Days