JN Engineer Interview Questions and Answers

Line protection relays are used for protecting transmission lines from faults.

• Line protection relays are used to detect faults in transmission lines and isolate them from the system.

• These relays can be of different types such as distance, differential, and directional relays.

• Distance relays measure the impedance of the line and trip when the impedance falls below a certain threshold.

• Differential relays compare the current entering and leaving the line and trip when there is a...read more

Master trip relay is a protective relay that trips all the circuit breakers in a power system in case of a fault.

• It is used to protect the power system from damage due to faults

• It is connected to all the circuit breakers in the system

• It operates when a fault is detected and trips all the circuit breakers simultaneously

• It is an important component of the protection system in power plants and substations

Event and DR are crucial in SCADA operation for ensuring system reliability and continuity.

• Event refers to any occurrence that requires attention or action, such as a fault or alarm.

• DR (Disaster Recovery) is a plan for restoring normal system operation in case of a catastrophic event.

• SCADA systems rely on event and DR management to ensure uninterrupted operation and prevent downtime.

• Examples of events in SCADA operation include power outages, equipment failures, and communica...read more

Transformer protection is essential to prevent damage and ensure safe operation.

• The protection system should detect and isolate faults quickly.

• Common protection methods include overcurrent, differential, and distance protection.

• Proper maintenance and testing of protection equipment is crucial.

• Examples of transformer protection devices include Buchholz relays, pressure relief devices, and temperature sensors.