In this course, the trainees will get a comprehensive overview of electrical substations in terms of voltage, types of efforts in power plants (high voltage – medium voltage – low voltage), how to choose operating voltage and voltage measuring devices and their types and how to calibrate them, how tests are carried out on circuit breakers High, medium and low voltage, clarifying the idea of working and operating the voltage change panel, knowing the operating and locking conditions for the shift operator, and knowing the preventive examination to ensure that the system works as required.