By the end of this course, participants will be able to:

• Understanding of the operational characteristics of MV switchgear.
• Understanding of troubleshooting procedures, as applied to MV switchgear.
• Improved capability in the use of test equipment.
• Better understanding of failure modes and failure analysis as applied to fuses, circuit breakers and switchgear. In relation to air break, vacuum and SF6 devices.
• Know the different types of circuit breakers and industrial switchgears
• Refreshed awareness of electrical safety concerns within substations and control centres
• Ability to determine fault levels in substations
• Demonstrate the maintenance, testing procedures used for separate voltage switchgear

The course is designed for Electrical engineers, supervisors and technicians

Day-1

General Introduction

• Three phase review and per unit
• Voltage levels
• One line and three line diagram
• Generation system layout
• Transmission system layout
• Substation system layout
• Distribution system layout

Switchgears equipment

• Fuses
• Auto-reclosers
• Automatic sectionalizer
• Circuit Breakers
• Isolator switches
• Load switches
• Relays
• Current transformers
• Voltage transformers

Day-2

Medium Voltage Vacuum CB

• Introduction
• Advantages of vacuum interruption
• Vacuum contactors and interrupters
• The vacuum medium
• The vacuum arc
• Vacuum arc stability
• Vacuum break down
• Vacuum switch construction
• Applications of vacuum circuit breakers

Modern Medium Voltage SF6 CB

• Basic Features of SF6 Breakers
• Dielectric properties of SF6
• Quenching properties of SF6
• Construction of SF6 breaker
• SF6 CB types
• Puffer type SF6 breakers
• Double Pressure System
• Single Pressure Puffer-Piston System
• Single Pressure Self Blast System
• Improvement in SF6 Breakers for HV

Day-3

OIL CIRCUIT BREAKERS

• Arc rupture under oil
• Advantages of oil
• Disadvantages of oil
• Plan break oil circuit breakers
• Arc control circuit oil breakers
• Minimum oil circuit breakers
• Construction and operation

CB Design Specification Based on Short Circuit Current Level

• Per unit system
• Faults on power systems
• Transient phenomena in power system.
• Symmetrical component analysis of three phase network
• Network connection for various fault types
• Current and voltage distribution in system due to a fault
• Effect of system on zero sequence quantities
• Computer programs based short circuit calculation.

Day-4

CB Design Specification Based on Arc Phenomena and Circuit Interruption

• Arc phenomena
• Maintenance of the Arc
• Properties of Arc
• Arc Interruption theory
• Circuit Breaker Rating
• Circuit constants and circuit conditions
• Conditions of severity
• Restriking voltage transient
• Class A ultra fast transients
• Class B system transients
• Class C low transients
• Transmission line transient
• Switching transients
• Duties of Switchgear

Circuit Breaker Inspection, Maintenance and Services

• Inspection
• General inspection technical procedure
• Daily inspection of circuit breakers
• Monthly inspection of circuit breakers
• Annual inspection of circuit breakers
• Disassembly
• Cleaning
• Tightening
• Lubrication
• Equipments used in testing
• Testing procedure
• Contact resistance test.
• Insulation resistance test
• Test report

Day-5

Circuit Breakers Control, Protection and Testing

• Switchgears control devices and wiring
• Switchgears protection devices and wiring
• Testing Classification
• Testing laboratories
• Description of a simple testing station

CB TROUBLESHOOTING

• Low insulation resistance
• Resistance between terminals
• Unequal contact wipe and travel in 3-pole
• Phase terminal and earthed frame, with breaker closed
• Phase terminals of a pole.
• One of the pole doesn’t close.
• Breaker operation too Slow

CDGA attendance certificate will be issued to all attendees completing minimum of 80% of the total course duration.