50+ Senior Engineer- Maintenance Interview Questions and Answers

Answering questions related to maintenance and engineering

• Maintenance is crucial for ensuring the smooth functioning of machines and equipment

• Yes, I have experience in maintaining high power UPS systems

• Regular maintenance and timely repairs can reduce the n/d time of plant machines

• Yes, I have experience in in-house repair of VFDs and programming/commissioning

• I report to the Maintenance Manager or Plant Manager

• Yes, I have experience in calibrating process controllers

• The number...read more

Yes, I have knowledge of robot, press mc, thermoforming, Thermosetting, heater, oven, and utility.

• I have experience in maintaining and troubleshooting robots used in manufacturing processes.

• I am familiar with press machines and have worked on their maintenance and repair.

• I have knowledge of thermoforming processes and have worked on maintaining the equipment used in it.

• I am familiar with Thermosetting processes and have experience in maintaining the equipment used in it.

• I hav...read more

PLCs have various types of inputs and outputs for communication and control.

• PLCs have digital inputs and outputs for binary signals.

• Analog inputs and outputs are used for continuous signals.

• Specialized inputs and outputs include high-speed counters, pulse outputs, and communication modules.

• Examples of PLC input devices are push buttons, limit switches, and sensors.

• Examples of PLC output devices are motors, solenoids, and lights.

The pH of boiler feed pump water varies depending on the type of water treatment used.

• The pH of untreated water is typically around 7.0 (neutral)

• Water treatment chemicals can affect the pH of the water

• The ideal pH range for boiler feed water is between 8.5 and 9.5

• Maintaining proper pH levels can prevent corrosion and scaling in the boiler system

Hydraulic and pneumatic systems are used to transmit power using fluids or gases.

• Hydraulic systems use liquids such as oil to transmit power.

• Pneumatic systems use gases such as air to transmit power.

• Both systems use pumps or compressors to generate pressure.

• Hydraulic systems are commonly used in heavy machinery such as excavators and cranes.

• Pneumatic systems are commonly used in tools such as drills and impact wrenches.

Why analysis of problems is important in maintenance engineering?

• Identifies root cause of problems

• Helps in developing effective solutions

• Reduces downtime and maintenance costs

• Improves equipment reliability and performance

• Enables proactive maintenance approach

• Examples: Failure mode and effects analysis (FMEA), Root cause analysis (RCA), Fishbone diagram

Direct drive spindle is directly connected to the motor while belt drive spindle uses a belt to transfer power.

• Direct drive spindle has higher accuracy and faster response time.

• Belt drive spindle is less expensive and easier to maintain.

• Direct drive spindle is commonly used in high-end machines while belt drive spindle is used in low to mid-range machines.

• Examples of direct drive spindle machines include Mazak Integrex and Okuma Multus while examples of belt drive spindle mac...read more

I handle various types of packing machines in my role as a Senior Engineer- Maintenance.

• Handling vertical form fill seal machines

• Operating carton sealing machines

• Maintaining shrink wrapping machines

• Troubleshooting case packing machines

The film wastage target is set between 1.2% to 2% for maintenance purposes.

• Film wastage targets are crucial for cost control and efficiency.

• Regular monitoring and analysis of film wastage can help identify areas for improvement.

• Implementing measures such as training, process optimization, and equipment maintenance can help reduce film wastage.

• Examples of film wastage include unused film rolls, improper handling leading to tears or damage, and inefficient cutting processes.

Bearing number 6205 2z refers to a sealed deep groove ball bearing.

• 6205 2z indicates a deep groove ball bearing with metal shields on both sides

• The '2z' in the bearing number signifies the type of sealing, in this case metal shields

• This type of bearing is commonly used in applications where protection from contaminants is required

The cenifuse machine is used for centrifugation, a process that separates substances of different densities.

• Centrifugation is a technique used in various industries, including biology, chemistry, and healthcare.

• The cenifuse machine spins samples at high speeds to generate centrifugal force.

• This force causes heavier particles to move towards the bottom while lighter particles move towards the top.

• The separated substances can then be collected and analyzed separately.

• In medical...read more

The question is about injection molding machine parts, working, and control system I/O interface, hydraulic motor types, and star delta working.

• Injection molding machine parts include the hopper, barrel, screw, nozzle, mold, and clamping unit.

• The control system I/O interface includes sensors, switches, and actuators.

• Hydraulic motor types include gear, vane, and piston motors.

• Star delta working is a method of starting and stopping three-phase motors.

Preventive maintenance is a proactive approach to maintenance that involves regularly scheduled inspections, repairs, and replacements to prevent equipment failure.

• Regularly scheduled inspections to identify potential issues before they become major problems

• Routine cleaning and lubrication to keep equipment running smoothly

• Replacing worn out parts before they fail to prevent costly breakdowns

• Creating a maintenance schedule based on manufacturer recommendations and equipment u...read more

Press machines use hydraulic or mechanical force to shape or cut materials.

• Press machines use a ram or piston to apply force to a material.

• Hydraulic press machines use fluid pressure to generate force.

• Mechanical press machines use a flywheel or motor to generate force.

• Press machines can be used for stamping, forging, punching, and more.

• Safety precautions must be taken when operating press machines to prevent accidents.

In critical situations, production planning involves prioritizing tasks, allocating resources efficiently, and communicating effectively.

• Identify the root cause of the critical situation

• Prioritize tasks based on impact on production and safety

• Allocate resources effectively to address the critical issues

• Communicate clearly with all stakeholders to ensure coordinated efforts

• Develop contingency plans for potential scenarios

A power pack is a device that converts mechanical energy into electrical energy. Its main components include an engine, generator, and control system.

• Power pack converts mechanical energy into electrical energy

• Main components include engine, generator, and control system

• Engine provides mechanical energy to generator

• Generator converts mechanical energy into electrical energy

• Control system regulates the power output

SAP T-codes are transaction codes used in SAP systems to execute specific functions.

• T-code SM01 is used to lock/unlock transactions

• T-code SE11 is used to create or modify database tables

• T-code MM01 is used to create a material master record

• T-code VA01 is used to create a sales order

• T-code FBL3N is used to display GL account line items

Parallelism and perpendicularity are crucial in press machines for accurate and consistent production.

• Parallelism ensures that the ram and bed of the press machine move in a straight line, preventing any deviation in the production process.

• Perpendicularity ensures that the ram and bed of the press machine move at a right angle to each other, preventing any twisting or bending of the material being pressed.

• Any deviation from parallelism or perpendicularity can result in defect...read more

The stroke of a hydraulic cylinder refers to the distance that the piston travels within the cylinder.

• The stroke is the linear movement of the piston within the cylinder.

• It is the distance between the fully retracted position and the fully extended position of the piston.

• The stroke determines the maximum extension or retraction of the cylinder.

• It is an important parameter in hydraulic system design and operation.

• For example, a hydraulic cylinder with a stroke of 10 inches can...read more

WaterJet is a technology that uses high-pressure water to cut or clean various materials.

• WaterJet can cut through materials like metal, stone, glass, and composites.

• It is often used in manufacturing, aerospace, and automotive industries.

• WaterJet can also be used for cleaning surfaces, such as removing paint or rust.

• There are two types of WaterJet: pure water and abrasive waterjet.

• Pure waterjet is used for cutting softer materials like foam or paper, while abrasive waterjet is...read more

KPI of maintenance department is to ensure maximum equipment uptime and minimize downtime.

• Reducing equipment downtime

• Increasing equipment reliability

• Improving maintenance efficiency

• Reducing maintenance costs

• Improving safety and compliance

• Increasing equipment lifespan

• Improving overall equipment effectiveness (OEE)

HMI on machines provides a user-friendly interface for operators to monitor and control the machine's functions.

• Allows operators to easily monitor machine status and performance

• Enables operators to input commands and adjust settings

• Improves efficiency and reduces downtime by providing real-time data

• Enhances safety by providing alerts and warnings to operators

• Can be customized to meet specific user needs and preferences

TDS stands for Total Dissolved Solids and DM Plant is used to remove impurities from water by ion exchange process.

• TDS refers to the total amount of dissolved solids in water, including minerals, salts, and metals.

• DM Plant, or Demineralization Plant, is used to remove impurities from water by passing it through ion exchange resins.

• The process involves exchanging ions in the water with ions attached to the resin beads, resulting in purified water.

• Regular maintenance of DM Plan...read more

The gas pressure of a cold room depends on the type of refrigerant used and the temperature inside the room.

• The gas pressure can range from 0 to 15 psi depending on the refrigerant used.

• The pressure will be higher if the temperature inside the room is lower.

• The pressure should be monitored regularly to ensure proper functioning of the refrigeration system.

• Common refrigerants used in cold rooms include R-404A, R-134a, and R-22.

Documentation of maintenance department is crucial for tracking equipment history and ensuring efficient operations.

• Maintain detailed records of equipment maintenance schedules and repairs

• Document all maintenance activities, including inspections and replacements

• Keep track of spare parts inventory and usage

• Create manuals and guides for equipment operation and maintenance

• Utilize computerized maintenance management systems (CMMS) for efficient documentation

Predictive maintenance is a proactive maintenance strategy that uses data analysis to predict when equipment failure is likely to occur.

• Predictive maintenance uses data from sensors and monitoring systems to predict when maintenance is needed.

• It helps in reducing downtime by allowing maintenance to be performed before a breakdown occurs.

• Examples of predictive maintenance techniques include vibration analysis, oil analysis, and thermal imaging.

• By implementing predictive mainte...read more

Hydraulic and pneumatic circuits are used in machinery to transmit power using fluids or gases.

• Hydraulic circuits use oil as the fluid to transmit power, while pneumatic circuits use air or gas.

• Both circuits consist of a pump/compressor, valves, actuators, and reservoirs.

• Hydraulic circuits are used in heavy machinery like excavators, while pneumatic circuits are used in tools like air compressors.

• Hydraulic circuits provide more power but pneumatic circuits are cleaner and eas...read more

Handled various maintenance documents including work orders, equipment manuals, and safety procedures.

• Work orders for scheduling and tracking maintenance tasks

• Equipment manuals for troubleshooting and repair

• Safety procedures for ensuring compliance and preventing accidents

CNC VMC machines are computer-controlled vertical milling machines used for precision cutting and shaping of metal and other materials.

• CNC stands for Computer Numerical Control, which means the machine is controlled by a computer program

• VMC stands for Vertical Machining Center, which means the spindle axis is vertically oriented

• These machines are used in manufacturing and engineering industries for high-precision work

• They can be used to create complex shapes and designs with ...read more

VMC is a vertical milling center while HMC is a horizontal milling center.

• VMC has a vertical spindle orientation while HMC has a horizontal spindle orientation.

• VMC is ideal for drilling and milling while HMC is best for heavy-duty cutting.

• VMC is more compact and takes up less floor space than HMC.

• VMC is generally less expensive than HMC.

• Examples of VMC include Haas VF-2 and DMG Mori CMX 1100 V while examples of HMC include Mazak HCN-5000 and Okuma MA-600HII.

The 500kva generator consumes approximately 75 liters of diesel per hour.

• 500kva generator consumes 150 liters of diesel in 2 hours

• Calculate consumption by dividing total liters by total hours

• Example: 500kva generator consumes 75 liters of diesel in 1 hour

5S is a methodology for workplace organization and efficiency. There are 5 types of S's that are used in this methodology.

• Sort - removing unnecessary items from the workplace

• Set in order - organizing the remaining items in a logical manner

• Shine - cleaning and maintaining the workplace

• Standardize - creating standard procedures for maintaining the workplace

• Sustain - ensuring that the 5S methodology is continuously implemented and improved upon

RO plant uses semi-permeable membrane to remove impurities from water, while DM plant uses ion exchange process to remove dissolved salts.

• RO plant works on the principle of reverse osmosis where water is forced through a semi-permeable membrane to remove impurities.

• DM plant works on the principle of ion exchange where ions are exchanged to remove dissolved salts from water.

• RO plant is used for removing larger particles and impurities, while DM plant is used for removing disso...read more

Preventive maintenance involves regularly scheduled inspections, repairs, and replacements to prevent equipment breakdowns.

• Regularly scheduled inspections

• Repairs and replacements as needed

• Prevents equipment breakdowns

• Increases equipment lifespan

• Reduces unexpected downtime

• Examples: changing air filters, lubricating moving parts, calibrating equipment

A water softener plant is a facility that removes minerals such as calcium and magnesium from water to make it 'soft'.

• Water softener plants use ion exchange resins to remove hardness minerals from water.

• They typically consist of a resin tank, brine tank, control valve, and a regeneration system.

• The resin in the tank attracts and traps calcium and magnesium ions, exchanging them for sodium ions.

• Regeneration involves flushing the resin with a salt solution to recharge it for fu...read more

Hydraulic and pneumatic systems are used in various industries for power transmission and control using fluids.

• Hydraulic systems use liquid (usually oil) to transmit power, while pneumatic systems use gas (usually air).

• Both systems rely on fluid pressure to generate force and motion.

• Hydraulic systems are typically used in heavy machinery like excavators and cranes, while pneumatic systems are common in industries like manufacturing and automation.

• Components of these systems i...read more

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

• It is installed between the transformer tank and conservator tank.

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

• It operates on the principle of gas collection and oil surge.

• It sends an alarm signal to the control room in case of any fault.

• It helps in preventing major faults and damage to the transformer.

Subol mechanical design includes spur gears, helical gears, bevel gears, worm gears, and planetary gears.

• Spur gears have straight teeth and are used for low-speed applications.

• Helical gears have angled teeth and are used for high-speed applications.

• Bevel gears have angled teeth and are used for changing the direction of power transmission.

• Worm gears have a screw-like structure and are used for high reduction ratios.

• Planetary gears have a central gear surrounded by satellite g...read more

A transmission is a mechanical device that transfers power from the engine to the wheels, allowing the vehicle to change speed and direction.

• Transmissions are commonly found in vehicles, such as cars, trucks, and motorcycles.

• They are responsible for transmitting power from the engine to the wheels.

• Transmissions allow the vehicle to change gears and adjust speed.

• There are different types of transmissions, including manual and automatic.

• Manual transmissions require the driver t...read more

Sensors are devices that detect and respond to physical stimuli.

• There are various types of sensors such as temperature sensors, pressure sensors, proximity sensors, motion sensors, etc.

• Some examples of sensors commonly used in maintenance include vibration sensors, acoustic sensors, and thermal imaging sensors.

• Sensors can be used to monitor equipment performance, detect faults, and predict maintenance needs.

• Advancements in sensor technology have led to the development of smar...read more

Valves are devices used to control the flow of fluids or gases. There are several types of valves used in various industries.

• Gate valve

• Ball valve

• Butterfly valve

• Globe valve

• Check valve

• Diaphragm valve

• Needle valve

• Pressure relief valve

Pressure in lobe compressor is maintained by adjusting the inlet and discharge valves, monitoring temperature and lubrication, and ensuring proper alignment.

• Adjust inlet and discharge valves to control pressure

• Monitor temperature to prevent overheating

• Ensure proper lubrication for smooth operation

• Check alignment of components for efficient compression

MTBF and MTTR are two important metrics used in maintenance engineering.

• MTBF stands for Mean Time Between Failures and is a measure of reliability.

• MTTR stands for Mean Time To Repair and is a measure of maintainability.

• MTBF = Total uptime / Number of failures

• MTTR = Total downtime / Number of repairs

• MTBF and MTTR are used to evaluate and improve maintenance processes.

Machine geometry procedures involve measuring and analyzing the physical dimensions and alignment of machines.

• Machine geometry procedures are used to ensure machines are operating at optimal performance.

• This involves measuring and analyzing various physical dimensions such as alignment, flatness, and roundness.

• Tools used for machine geometry procedures include laser alignment systems, dial indicators, and coordinate measuring machines.

• Regular machine geometry procedures can h...read more

A servo motor is an electrical device that rotates or moves parts with high precision and accuracy.

• Servo motors are commonly used in robotics, automation, and CNC machines.

• They have a small size and high torque output.

• They work by receiving a control signal that determines the position or speed of the motor.

• They can rotate continuously or move to a specific angle.

• Examples of servo motors include DC, AC, and brushless motors.

MTTR stands for Mean Time To Repair and MTBF stands for Mean Time Between Failures.

• MTTR is the average time taken to repair a failed component or system.

• MTBF is the average time between failures of a component or system.

• MTTR is usually measured in hours or days, while MTBF is also measured in hours or days.

• MTTR is an important metric in maintenance operations to assess the efficiency of repair processes.

• MTBF is used to predict the reliability of a system or component.

• For exam...read more

I have extensive experience in maintenance of mechanical, electrical and electronic equipment.

• Proficient in troubleshooting and repairing equipment

• Skilled in preventive maintenance and predictive maintenance techniques

• Familiar with PLC programming and automation systems

• Experience in managing maintenance teams and projects

• Knowledge of safety regulations and compliance standards