Electrical Operations Engineer Interview Questions and Answers

LV circuit breaker with coupling breaker is used for protection and isolation of electrical circuits.

• LV circuit breaker is a device that automatically interrupts the flow of current in an electrical circuit.

• Coupling breaker is used to connect or disconnect two circuits.

• LV circuit breaker with coupling breaker is used to protect and isolate electrical circuits.

• It is commonly used in power distribution systems.

• It helps in preventing damage to equipment and ensuring safety of pe...read more

Primary injection testing is a method to verify the performance of a circuit breaker or protective relay.

• Primary injection testing involves injecting a high current into the circuit to simulate a fault condition.

• The current is measured and compared to the expected values to ensure the circuit breaker or relay is functioning properly.

• Calculations involve determining the expected current based on the system voltage, impedance, and other factors.

• Primary injection testing is typi...read more

The 87T transformer differential testing procedure is used to test the differential relay protection system of a transformer.

• Disconnect the transformer from the power source

• Connect the relay test set to the differential relay

• Inject current into the relay and measure the response

• Compare the results with the expected values

• Perform a secondary injection test to verify the accuracy of the test set

• Document the test results