10+ Electrical Shift Engineer Interview Questions and Answers

Dry type and oil type are two types of transformers based on the insulation used.

• Dry type transformers use air as insulation while oil type transformers use oil as insulation.

• Dry type transformers are safer and more environmentally friendly than oil type transformers.

• Oil type transformers are more efficient and can handle higher loads than dry type transformers.

• Dry type transformers are typically used in indoor applications while oil type transformers are used in outdoor appl...read more

Power factor is the ratio of real power to apparent power in an AC circuit. It can be maintained by using capacitors or inductors.

• Power factor is a measure of how efficiently electrical power is being used

• It is expressed as a decimal or a percentage

• A power factor of 1 means all the power is being used efficiently

• A power factor less than 1 means some power is being wasted

• Capacitors or inductors can be used to correct power factor

• Power factor correction can reduce energy costs ...read more

Current transformers and potential transformers are used for measuring electrical parameters.

• Current transformers are used to measure high currents in power systems and step down the current to a level that can be measured by instruments.

• Potential transformers are used to measure high voltages in power systems and step down the voltage to a level that can be measured by instruments.

• Both transformers are used to provide accurate measurements of electrical parameters such as cu...read more

Differential protection is a type of transformer protection that compares the currents entering and leaving the transformer.

• Differential protection is based on Kirchhoff's current law.

• If the difference between the currents is greater than a set threshold, the protection system will trip.

• This type of protection is used to detect internal faults in the transformer.

• Differential protection can be applied to both power and distribution transformers.

Transmission lines carry electricity from power plants to distribution substations.

• Transmission lines are typically high voltage and operate at 69 kV or higher

• They are designed to minimize power loss and maximize efficiency

• Transmission lines can be overhead or underground

• Distribution substations step down the voltage for use in homes and businesses

A current transformer is a type of instrument transformer that is used to step down high currents to a lower, more manageable level for measurement or protection purposes.

• Current transformers are typically used in conjunction with ammeters, wattmeters, and protective relays.

• They have a primary winding that is connected in series with the circuit carrying the current to be measured, and a secondary winding that is connected to the measuring or protection device.

• The secondary c...read more

A potential transformer is a type of instrument transformer used to step down high voltage to a lower, safer voltage for measurement or control purposes.

• Used to step down high voltage to a lower, safer voltage

• Commonly used in power systems for metering and protection purposes

• Provides accurate voltage measurements for monitoring and control systems

A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction.

• Consists of two or more coils of insulated wire wound around a core

• Primary coil receives electrical energy and induces a magnetic field in the core

• Secondary coil receives the magnetic field and converts it back into electrical energy

• Used to step up or step down voltage levels in power distribution systems

66kv lines are used for transmitting electricity over long distances with minimal power loss.

• 66kv lines are used for long distance transmission of electricity

• Higher voltage reduces power loss during transmission

• 66kv is a common voltage level for transmission lines

• Lower voltage lines would result in higher power losses

HVAC stands for Heating, Ventilation, and Air Conditioning system which is responsible for providing thermal comfort and acceptable indoor air quality.

• HVAC system controls the temperature, humidity, and air quality in a building or vehicle.

• It includes components such as furnaces, air conditioners, heat pumps, ductwork, and thermostats.

• HVAC systems can be centralized or decentralized depending on the size and layout of the building.

• Regular maintenance of HVAC systems is import...read more

A breaker is an electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit.

• Breakers automatically stop the flow of electricity when a fault is detected.

• They come in different types such as circuit breakers, fuse boxes, and residual-current devices.

• Breakers can be reset manually after tripping to restore power.

• Common brands of breakers include Siemens, Schneider Electric, and Eaton.

Buchholz relay is a protective device used in oil-filled transformers to detect and prevent faults.

• It is installed in the oil-filled transformer tank.

• It detects the presence of gas or oil flow in the transformer oil.

• It trips the transformer if any fault is detected.

• It is a type of gas actuated relay.

• It is named after its inventor Max Buchholz.

Conductor size is determined by the amount of current it needs to carry and the distance it needs to travel.

• Conductor size is measured in American Wire Gauge (AWG) or circular mils (CM)

• Larger conductors can carry more current without overheating

• Distance also affects conductor size as longer distances require larger conductors to prevent voltage drop

• Conductor size is also determined by the type of insulation and the environment it will be used in

• For example, a 12 AWG conductor...read more

Implemented a preventive maintenance program to reduce downtime and increase equipment reliability.

• Developed and executed maintenance schedules for critical equipment.

• Implemented a system for tracking equipment performance and maintenance history.

• Collaborated with production team to identify and address equipment issues in a timely manner.

• Conducted regular inspections and testing to ensure equipment was operating within specifications.

• Trained and supervised maintenance staff ...read more

Transformers are of two types - Step-up and Step-down transformers.

• Step-up transformers increase voltage and decrease current

• Step-down transformers decrease voltage and increase current

• Other types include isolation transformers, autotransformers, and instrument transformers

• Isolation transformers provide electrical isolation between primary and secondary windings

• Autotransformers have a single winding that acts as both primary and secondary

• Instrument transformers are used for m...read more

CB stands for Circuit Breaker, which is used to protect electrical circuits from overloads and short circuits.

• There are different types of circuit breakers such as air circuit breakers, oil circuit breakers, vacuum circuit breakers, and SF6 circuit breakers.

• Air circuit breakers are commonly used in low voltage applications, while oil circuit breakers are used in high voltage applications.

• Vacuum circuit breakers are used in medium voltage applications, and SF6 circuit breakers...read more