Electrical Incharge Interview Questions and Answers

DG stands for Diesel Generator. It is used as a backup power source in case of power outages or emergencies.

• DG is connected to the existing electrical network through an Automatic Transfer Switch (ATS)

• The ATS detects when there is a power outage and automatically switches the power source from the main grid to the DG

• Once the main power is restored, the ATS switches the power source back to the grid and the DG is turned off

• The DG should be properly sized to meet the power requ...read more

Motor and transformer protection schemes are used to prevent damage to the equipment and ensure safe operation.

• Motor protection schemes include overload protection, short circuit protection, and earth fault protection.

• Transformer protection schemes include overcurrent protection, differential protection, and earth fault protection.

• Motor and transformer protection schemes can be achieved through the use of fuses, circuit breakers, relays, and other protective devices.

• Proper ma...read more

Parameters checked daily in a transformer include temperature, oil level, and cooling system.

• Temperature of the transformer should be monitored to ensure it is within safe operating limits.

• Oil level in the transformer should be checked to ensure proper lubrication and insulation.

• Cooling system of the transformer should be inspected to ensure efficient heat dissipation.

• Any abnormal noise or vibration should be investigated to prevent potential issues.

• Regular visual inspection ...read more

Reverse synchronisation relay is a protective relay used to prevent the generator from being synchronized with the grid in the wrong direction.

• It is used to prevent the generator from being synchronized with the grid in the wrong direction

• It detects the reverse power flow from the grid to the generator

• It trips the generator breaker if the reverse power flow exceeds a certain limit

• It is important for the safety of the generator and the grid

Transformer oil tests include dielectric strength, acidity, interfacial tension, and dissolved gas analysis.

• Dielectric strength test measures the ability of oil to withstand electrical stress

• Acidity test determines the acidity level of oil

• Interfacial tension test measures the oil's ability to separate from water

• Dissolved gas analysis identifies the presence of gases in the oil, indicating potential faults in the transformer

• Other tests include flash point, viscosity, and color