Special Technical Services Interview Questions, Process, and Tips

A centrifugal compressor is a type of dynamic compressor that uses a rotating impeller to increase the pressure and flow of a gas.

• It works by converting kinetic energy into potential energy.

• It is commonly used in HVAC systems, gas turbines, and refrigeration systems.

• It is more efficient than positive displacement compressors for high flow rates and low pressure differentials.

• It can be single-stage or multi-stage, depen...read more

Chillers are machines that remove heat from a liquid via a vapor-compression or absorption refrigeration cycle.

• Components include compressor, condenser, evaporator, expansion valve, and refrigerant.

• Types of chillers include air-cooled, water-cooled, and absorption chillers.

• Chillers are commonly used in HVAC systems for cooling large buildings or industrial processes.

Risk assessment involves identifying hazards, evaluating risks, implementing control measures, and reviewing effectiveness.

• Identify hazards present in the workplace

• Evaluate the risks associated with each hazard

• Implement control measures to reduce or eliminate risks

• Review the effectiveness of the control measures

• Document the risk assessment process and findings

To check IR of XLPE cable, use a megger to measure insulation resistance.

• Use a megger to measure insulation resistance of XLPE cable

• Ensure the cable is de-energized before testing

• Compare the measured IR value with the manufacturer's specifications

• Repeat the test at different points along the cable for accuracy

Tests for transformers include turns ratio test, insulation resistance test, power factor test, and winding resistance test.

• Turns ratio test measures the turns ratio between primary and secondary windings.

• Insulation resistance test checks the insulation resistance of the transformer windings.

• Power factor test evaluates the power factor of the transformer.

• Winding resistance test measures the resistance of the transforme

Types of excavations include trench excavation, basement excavation, road excavation, and pit excavation.

• Trench excavation involves digging a narrow channel in the ground for laying pipes or cables.

• Basement excavation is the process of digging out the foundation of a building to create a below-ground level.

• Road excavation is the removal of soil and rocks to construct or repair roads.

• Pit excavation involves digging a la...read more