Efs Facilities Services Electrical Technician Interview Questions and Answers

A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. Safety measures are important to prevent accidents and ensure proper functioning of transformers.

• A transformer is used to step up or step down voltage levels in electrical systems.

• It consists of two or more coils of wire, known as windings, which are wound around a core made of magnetic...read more

DG stands for Diesel Generator. It is a type of generator that uses diesel fuel to produce electrical energy.

• DG is commonly used as a backup power source in case of power outages.

• It consists of an engine that runs on diesel fuel and an alternator that converts mechanical energy into electrical energy.

• DG sets are often used in industries, commercial buildings, and residential complexes.

• They are capable of providing powe...read more

Transformer vector group is a method used to represent the phase shift between the primary and secondary windings of a transformer.

• Transformer vector group indicates the relationship between the primary and secondary winding phases.

• It helps in determining the connection and phase shift of the transformer windings.

• Common vector groups include Yy0, Yd1, Dyn11, etc.

• Vector group is important for parallel operation of trans

VBD test is conducted in transformers to ensure insulation integrity and detect any potential faults.

• VBD test helps in identifying any weak spots in the insulation of the transformer

• It helps in preventing breakdowns and ensuring the safety and reliability of the transformer

• By conducting VBD test, any potential faults can be detected early and necessary maintenance can be carried out

• It is a standard procedure in transfo

ACB stands for Air Circuit Breaker, which is a type of circuit breaker used to protect electrical circuits from overloads and short circuits.

• ACB is commonly used in low voltage power distribution systems

• It operates by automatically cutting off the power supply when a fault is detected

• ACBs are more reliable and require less maintenance compared to other types of circuit breakers

• Examples of ACB manufacturers include Schn

Contractors are individuals or companies hired to perform specific tasks or projects for a client or organization.

• Contractors are not employees of the client or organization, but rather work independently or as part of their own company.

• They are typically hired for a specific period of time or project, and are paid based on the terms of their contract.

• Examples of contractors include construction workers, freelance writ...read more

A relay is an electrically operated switch that opens or closes circuits electromechanically.

• Relays are used to control high voltage circuits with low voltage signals.

• They consist of a coil, an armature, and a set of contacts.

• When the coil is energized, the armature moves and the contacts either open or close.

• Relays are commonly used in industrial control systems, automotive applications, and household appliances.

• Examp...read more

Circuit breakers are essential safety devices that protect electrical circuits from overloads and short circuits.

• Circuit breakers automatically cut off power when there is an overload or short circuit to prevent damage to the electrical system.

• They are more convenient and safer than fuses, as they can be easily reset after tripping.

• There are different types of circuit breakers, such as thermal, magnetic, and combinatio...read more