FerAux Engineering Interview Questions and Answers

The oil used in power transformers is called transformer oil. It typically contains elements such as carbon, hydrogen, and oxygen.

• Transformer oil is typically mineral oil-based, such as naphthenic or paraffinic oil.

• Elements found in transformer oil include carbon, hydrogen, and oxygen.

• Other elements like sulfur may also be present in transformer oil.

SF6 circuit breaker is a type of circuit breaker that uses sulfur hexafluoride gas as the insulating and arc extinguishing medium. Testing of power transformers involves various electrical tests to ensure proper functioning.

• SF6 circuit breaker uses SF6 gas for insulation and arc extinguishing

• Testing of power transformers includes insulation resistance test, turns ratio test, and power factor test

• SF6 circuit breakers are commonly used in high voltage applications

• Power transfor...read more

NGR stands for Neutral Grounding Resistor. It limits fault current and protects equipment.

• Limits fault current during ground faults

• Protects equipment from damage

• Improves safety by reducing risk of electric shock

• Commonly used in power distribution systems

• Example: NGR is used in transformer neutral grounding to limit fault current

There are three main types of testing for isolators: mechanical testing, electrical testing, and functional testing.

• Mechanical testing involves checking the physical components of the isolator such as the contacts, insulators, and operating mechanism.

• Electrical testing includes measuring the insulation resistance, contact resistance, and dielectric strength of the isolator.

• Functional testing verifies that the isolator operates correctly under load conditions and isolates the ...read more

Mesh earthing is a type of grounding system where multiple interconnected conductors are buried in the ground to provide a low impedance path for fault currents.

• Mesh earthing involves burying multiple interconnected conductors in the ground.

• It provides a low impedance path for fault currents to safely dissipate into the ground.

• This type of grounding system is commonly used in electrical installations to protect against electrical faults and lightning strikes.