Preview Questions Substation Technician | Role Specific Skill

Question 1: How do you test the current transformer (CT) accuracy in a substation?

Which action should you take?

Choose only one option

By applying a known current and measuring the output to compare with the transformer's rated accuracy class

By measuring the physical condition of the CT only

By ignoring the accuracy test if the CT shows no visible damage

By checking the connection of the CT to the protection relay

Question 2: How do you ensure that the transformer oil is free from contaminants during maintenance?

Which action should you take?

Choose only one option

By performing oil filtration, degassing, and chemical testing to ensure oil purity

By checking the oil level and assuming the oil is clean

By performing a simple color check of the oil

By replacing the oil only when the transformer is decommissioned

Question 3: How do you diagnose a fault in a circuit breaker that trips without a fault being present?

Which action should you take?

Choose only one option

By resetting the breaker and observing its operation

By ignoring the breaker and focusing on the load conditions

By replacing the circuit breaker without further diagnostic tests

By performing insulation resistance tests, checking the protective relays, and verifying the breaker's trip settings

Question 4: When should infrared thermography be used in a substation?

Which action should you take?

Choose only one option

To check the insulation resistance of cables

To measure load currents in electrical equipment

To monitor system frequency and voltage variations

To detect overheating components that could indicate a failure

Question 5: How do you perform a timing test on a circuit breaker using a timing device?

Which action should you take?

Choose only one option

By observing the breaker's operation and estimating the response time

By measuring the time it takes for the breaker to open manually

By using the circuit breaker's internal timer without external verification

By applying a test signal to the breaker and using a timing device to measure the response time

Question 6: What type of fault is most likely if a circuit breaker shows an abnormal rise in current but no visible fault occurs?

Which action should you take?

Choose only one option

Open-circuit fault

Ground fault

Intermittent short circuit

High-resistance fault