700+ Maintenance Engineer Interview Questions and Answers

The refrigeration cycle used in a chilling plant is typically the vapor compression cycle.

• The vapor compression cycle involves compressing refrigerant vapor to increase its temperature and pressure.

• The high-pressure vapor then condenses into a liquid, releasing heat.

• The liquid refrigerant then passes through an expansion valve, reducing its pressure and temperature.

• The low-pressure liquid then evaporates, absorbing heat and cooling the surrounding area.

• This cycle is commonly ...read more

There are several types of valves in instrumentation.

• Gate valve

• Ball valve

• Butterfly valve

• Globe valve

• Check valve

• Diaphragm valve

• Needle valve

• Plug valve

• Pressure relief valve

• Safety valve

Heat treatment of metals involves processes like hardening, tumbling, and tempering. Various equipment and testing methods are used.

• Processes involved in heat treatment: hardening, tumbling, and tempering

• Equipment used: furnaces, quenching tanks, tempering ovens

• Temperature settings for desired hardness quality vary depending on the metal

• Testing methods for hardness: Rockwell hardness test, Brinell hardness test

• Hardening operation involves heating the metal above its critical ...read more

Hydraulic pressure is measured in bar and NAC is not a commonly used term in this context.

• Hydraulic pressure is typically measured in bar or psi

• The amount of pressure required depends on the specific system and application

• NAC is not a commonly used term in the context of hydraulic systems

Air fuel ratio in boiler is the ratio of mass of air to mass of fuel. It is maintained by adjusting the fuel and air flow rates.

• Air fuel ratio is critical for efficient combustion and minimizing emissions.

• The ideal air fuel ratio for a boiler is typically between 1.5 and 2.5.

• To maintain the air fuel ratio, the fuel and air flow rates must be adjusted based on the boiler load and combustion conditions.

• Excess air can lead to energy waste and increased emissions, while insuffici...read more

The voltage of the DC battery used in Jio towers is typically 48 volts.

• The standard voltage for DC batteries in telecom towers is 48 volts.

• This voltage is chosen for its efficiency and compatibility with telecom equipment.

• Other voltages like 24 volts or 60 volts may also be used depending on specific requirements.

• The voltage is regulated and maintained by power supply systems in the tower.

• Higher voltage batteries may be used for backup power in case of outages.

Noise from high tension lines is caused by electromagnetic interference and corona discharge.

• High tension lines carry high voltage electricity, which can cause electromagnetic interference.

• Electromagnetic interference can generate noise in nearby electronic devices and equipment.

• Corona discharge occurs when the electric field surrounding the high tension line ionizes the air, creating a buzzing or crackling sound.

• Corona discharge can also produce radio frequency interference,...read more

Heat transfer is the movement of thermal energy from one object to another. There are three modes of heat transfer: conduction, convection, and radiation.

• Conduction is the transfer of heat through a material without any movement of the material itself. Example: Touching a hot stove.

• Convection is the transfer of heat through the movement of fluids (liquids or gases). Example: Boiling water.

• Radiation is the transfer of heat through electromagnetic waves. Example: Feeling the wa...read more

I maintain the jio tower site by conducting regular inspections, performing preventive maintenance, and addressing any issues promptly.

• Conduct regular inspections to identify any potential issues or maintenance needs

• Perform preventive maintenance tasks such as cleaning, lubricating, and replacing parts

• Address any issues or repairs promptly to minimize downtime

• Keep detailed records of maintenance activities and equipment performance

• Coordinate with other team members and contra...read more

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

• Transformers work on the principle of electromagnetic induction.

• They consist of two or more coils of wire, known as windings, which are wound around a core made of magnetic material.

• When an alternating current (AC) flows through the primary winding, it creates a changing magnetic field in the core.

• This changing magnetic field induces a voltage ...read more

Yes, chemical treatment is done in cooling tower to prevent scaling, corrosion and biological growth.

• Chemicals like biocides, scale inhibitors and corrosion inhibitors are added to the water in cooling tower.

• Biocides are used to prevent the growth of bacteria, algae and fungi.

• Scale inhibitors are used to prevent the formation of mineral deposits on the tower walls and heat exchangers.

• Corrosion inhibitors are used to prevent the corrosion of metal components in the tower.

• The t...read more

Yes, I have knowledge and experience in moulding, machine installation and commissioning, and handling utility and HT department during breakdowns.

• I have experience in working with moulding machines and can handle them efficiently.

• I am well-versed with the installation and commissioning of machines and can ensure their proper alignment.

• I have experience in handling utility and HT departments during breakdowns and can troubleshoot and resolve issues effectively.

• I am familiar w...read more

Maintenance involves the activities required to keep equipment, machinery, and facilities in good working condition.

• Maintenance includes preventive maintenance, corrective maintenance, and predictive maintenance.

• Preventive maintenance involves regularly scheduled inspections, cleaning, and servicing to prevent breakdowns.

• Corrective maintenance involves repairing or replacing faulty equipment or components.

• Predictive maintenance uses data and analytics to anticipate and addres...read more

Basic mechanical work in wind turbines includes maintenance, troubleshooting, and repair of components such as blades, gearbox, and generator.

• Inspecting and repairing wind turbine blades for damage or wear

• Performing regular maintenance on gearbox and generator

• Troubleshooting and repairing electrical and mechanical issues

• Replacing faulty components like bearings, gears, or sensors

• Performing alignment and balancing of rotating parts

• Ensuring proper lubrication of moving parts

• Mon...read more

Various equipments are used in pharmaceutical industries for different purposes.

• Mixers and blenders for mixing ingredients

• Filtration systems for purifying liquids

• Centrifuges for separating solids from liquids

• Autoclaves for sterilizing equipment

• Tablet presses for manufacturing tablets

• Capsule filling machines for filling capsules

• Packaging machines for packaging finished products

• HVAC systems for maintaining controlled environments

• Water purification systems for producing purified...read more

Parameters to consider when building a cooling tower

• Size and capacity requirements

• Location and environmental factors

• Design and construction materials

• Water source and quality

• Cooling tower type and configuration

• Safety and regulatory compliance

When encountering technical issues, it is important to follow a systematic approach to identify, troubleshoot, and resolve the problem.

• Start by gathering information about the issue, such as error messages, symptoms, and any recent changes or events that may have triggered the problem.

• Analyze the available data to narrow down the possible causes of the issue.

• Use diagnostic tools and techniques to further investigate and isolate the root cause.

• Develop a plan of action to addre...read more

The hydraulic pack pressure varies depending on the specific system and application.

• Hydraulic pack pressure is the force exerted by the hydraulic fluid in a hydraulic system.

• It is typically measured in pounds per square inch (psi) or bar.

• The pressure can vary based on the load requirements, system design, and component specifications.

• Higher pressure is often required for heavy-duty applications, while lower pressure may be sufficient for lighter tasks.

• For example, a hydraulic...read more

Answering questions related to conveyor calculation, plunger pump, negative pressure, and ballmill troubleshooting.

• Conveyor calculation involves determining the belt speed, capacity, and power requirements.

• A plunger pump works by using a reciprocating plunger to move fluid through a cylinder.

• Negative pressure is a pressure that is lower than the atmospheric pressure.

• If a ballmill suddenly stops while running, the first step is to check the power supply and circuit breaker.

• Oth...read more

A P-V diagram of a double stage air compressor shows the pressure-volume relationship during compression.

• The diagram consists of two stages of compression.

• The first stage compresses the air from atmospheric pressure to an intermediate pressure.

• The second stage compresses the air from the intermediate pressure to the final pressure.

• The volume decreases as the pressure increases during compression.

• The diagram can be used to analyze the efficiency and performance of the compress...read more

Preventive maintenance is a proactive approach to maintenance that involves regular inspections and repairs to prevent equipment failure.

• Preventive maintenance involves scheduled inspections and repairs to prevent equipment failure

• It is a proactive approach to maintenance that reduces downtime and extends equipment life

• Examples include changing oil and filters, cleaning equipment, and replacing worn parts

• Preventive maintenance can be time-based or condition-based

• Time-based ma...read more

Yes, I have experience in boiler passing. It involves a thorough inspection of the boiler to ensure its safe and efficient operation.

• Boiler passing involves a visual inspection of the boiler's exterior and interior components.

• The inspection includes checking for leaks, cracks, corrosion, and other signs of wear and tear.

• The boiler's safety controls, valves, and gauges are also checked to ensure they are functioning properly.

• If any issues are found, repairs or replacements may...read more

The grade of materials used in storage tanks depends on the type of fluid being stored and the tank's operating conditions.

• The material should be compatible with the stored fluid to prevent corrosion or contamination.

• Common materials used for storage tanks include carbon steel, stainless steel, and aluminum.

• The thickness of the material should be sufficient to withstand the pressure and temperature of the stored fluid.

• The material should also be resistant to environmental fac...read more

To diagnose wiring and electrical faults, a maintenance engineer can follow these steps:

• Start by visually inspecting the wiring and electrical components for any visible damage or loose connections.

• Use a multimeter to test the continuity of wires and check for voltage drops or fluctuations.

• Perform insulation resistance tests to identify any insulation breakdown or leakage.

• Utilize circuit testers or voltage detectors to determine if power is reaching the intended destinations....read more

Questions related to maintenance engineering including eddy current, 5S TPM, electromagnetic induction, RPM measurement, DC motor, shift handover, major breakdown, and star delta starter.

• Eddy current is a current induced in a conductor due to a changing magnetic field

• 5S TPM is a methodology for workplace organization and standardization

• Electromagnetic induction is the production of an electromotive force across a conductor due to a changing magnetic field

• RPM measurement can b...read more

To improve the power factor of a 130 kW load with a power factor of 0.7, capacitors can be used. The required rating of the capacitor depends on the desired power factor improvement.

• Install capacitors in parallel with the load to improve power factor

• Calculate the required capacitance using the formula: C = (P * tan(acos(pf))) / (V^2)

• Choose capacitors with the appropriate voltage and capacitance rating for the load

• Ensure proper installation and maintenance of the capacitors to...read more

A vapour compression cycle is a process used in refrigeration systems to remove heat from a space.

• The cycle consists of four main components: a compressor, a condenser, an expansion valve, and an evaporator.

• The compressor takes in low-pressure refrigerant gas and compresses it to high pressure.

• The high-pressure gas then flows to the condenser, where it releases heat and condenses into a high-pressure liquid.

• The liquid then flows through the expansion valve, where it undergoes...read more