80+ Maintenance Technician Interview Questions and Answers

I can maintain and operate a variety of machines.

• I have experience maintaining and operating industrial machinery such as conveyor systems, packaging machines, and hydraulic presses.

• I am skilled in troubleshooting and repairing electrical and mechanical issues in machines.

• I can also operate heavy machinery like forklifts and cranes.

• I am familiar with following maintenance schedules, conducting inspections, and performing preventive maintenance tasks.

• I have knowledge of safety...read more

The input voltage of 3 phase transformers is typically 480 volts, while the output voltage can vary depending on the application.

• Input voltage of 3 phase transformers is usually 480 volts

• Output voltage can vary based on the application

• Common output voltages include 208V, 240V, and 480V

To get rid of dry soldering, you can try reflowing the solder, cleaning the surface, using flux, or replacing the solder altogether.

• Reflow the solder by applying heat to melt and reflow the dry solder joints.

• Clean the surface by removing any dirt, oxidation, or contaminants that may be affecting the soldering process.

• Use flux to improve the wetting and flow of the solder, making it easier to create strong and reliable solder joints.

• Consider replacing the solder altogether if ...read more

There are several types of circuit breakers including thermal-magnetic, magnetic, and hydraulic-magnetic. They are used to protect electrical circuits from overloads and short circuits.

• Types of circuit breakers include thermal-magnetic, magnetic, and hydraulic-magnetic

• Thermal-magnetic circuit breakers use a bimetallic strip to respond to overloads

• Magnetic circuit breakers use a solenoid to respond to overloads

• Hydraulic-magnetic circuit breakers use a hydraulic delay to respon...read more

Maintaining spare parts involves regular inventory checks, ordering replacements in advance, and ensuring proper storage.

• Regularly conduct inventory checks to identify any missing or damaged spare parts.

• Order replacements in advance to avoid downtime in case of equipment failure.

• Ensure proper storage of spare parts to prevent damage or deterioration.

• Keep track of usage patterns to anticipate future spare parts needs.

• Establish relationships with reliable suppliers for timely d...read more

A safety circuit is an electrical circuit designed to protect people and equipment from potential hazards.

• A safety circuit typically includes components such as emergency stop buttons, safety switches, and safety relays.

• It is used to monitor and control the operation of machinery or equipment to ensure safe operation.

• When a safety hazard is detected, the safety circuit will activate protective measures, such as stopping the machinery or isolating power.

• Safety circuits are com...read more

Oil transformers use oil as a cooling and insulating medium, while dry type transformers use air or solid insulation materials.

• Oil transformers use oil as a cooling and insulating medium, while dry type transformers use air or solid insulation materials.

• Oil transformers are typically used in high-power applications due to better heat dissipation capabilities.

• Dry type transformers are more environmentally friendly as they do not contain oil, reducing the risk of oil leaks or s...read more

To enter running conditions of escalators in the basement, follow safety protocols, check for any obstructions, and ensure proper functioning of all components.

• Follow safety protocols before entering the basement area with running escalators.

• Check for any obstructions or debris that may interfere with the escalator's operation.

• Ensure all components of the escalator are functioning properly before entering the basement area.

• Coordinate with other team members or personnel to sa...read more

There are various types of generators and cameras used in maintenance work.

• Types of generators include diesel, natural gas, propane, and gasoline generators.

• Cameras used in maintenance work include thermal imaging cameras, borescopes, and infrared cameras.

• Thermal imaging cameras are used to detect heat signatures and identify potential issues in electrical systems.

• Borescopes are used to inspect hard-to-reach areas such as pipes and engines.

• Infrared cameras are used to detect ...read more

Water treatment plants work by removing contaminants from water to make it safe for consumption.

• Water treatment plants use processes like coagulation, sedimentation, filtration, and disinfection to remove contaminants.

• Coagulation involves adding chemicals to water to make particles clump together and settle out.

• Sedimentation allows the larger particles to settle at the bottom of the water.

• Filtration involves passing water through layers of sand, gravel, and charcoal to remove...read more

Safety should always be the top priority in order to prevent accidents and ensure the well-being of employees.

• Safety should always come first to prevent accidents and injuries.

• Maintenance can be scheduled or postponed, but safety should never be compromised.

• Prioritizing safety creates a culture of care and responsibility in the workplace.

• Examples: Lockout/tagout procedures, wearing proper PPE, conducting regular safety inspections.

Parel and series are types of electrical circuits used in electronics.

• Parel circuit is a type of circuit where the components are connected in parallel to each other.

• Series circuit is a type of circuit where the components are connected in a single path.

• In a parallel circuit, the voltage across each component is the same, while in a series circuit, the voltage is divided among the components.

• Examples of parallel circuits include household wiring and electronic devices with mu...read more

There are three input phase wires in 3 phase transformers.

• Three input phase wires are required for 3 phase transformers.

• Each phase wire carries a different phase of the electrical current.

• Examples: R, Y, B phases in a 3 phase system.

The input voltage of 3 phase transformers is typically 480 volts in industrial settings.

• Input voltage of 3 phase transformers is commonly 480 volts in industrial applications

• Other common input voltages for 3 phase transformers include 208 volts and 240 volts

• Input voltage may vary depending on the specific application and transformer design

I am skilled in various fields such as electrical, plumbing, HVAC, and carpentry.

• Skilled in electrical work

• Experienced in plumbing repairs

• Knowledgeable in HVAC systems

• Proficient in carpentry tasks

MCB stands for Miniature Circuit Breaker. It is an electrical switch that automatically shuts off the electrical circuit during an overload or short circuit.

• MCB is a type of circuit breaker that is commonly used in residential and commercial buildings.

• It is designed to protect electrical circuits from damage caused by overloading or short circuits.

• When an overload or short circuit occurs, the MCB automatically trips and shuts off the electrical circuit.

• MCBs are available in d...read more

There are various types of valves used in hydraulic systems, including directional control valves, pressure control valves, and flow control valves.

• Directional control valves control the direction of fluid flow in the system, such as a spool valve.

• Pressure control valves regulate the pressure of the fluid, such as a relief valve.

• Flow control valves regulate the flow rate of the fluid, such as a needle valve.

• Other types of valves include check valves, ball valves, and gate val...read more

Working a phase in electricity involves understanding the flow of current and voltage in a circuit.

• A phase is a single alternating current waveform that is part of a larger electrical system

• Working a phase involves understanding the phase angle, which is the difference in timing between the voltage and current waveforms

• Phase rotation is important to ensure that all phases are in the correct order and voltage is balanced

• Examples of phase-related tasks include measuring voltage...read more

To handle a paint shop conveyor breakdown, I would first assess the issue, troubleshoot the problem, repair or replace faulty parts, and ensure proper maintenance to prevent future breakdowns.

• Assess the issue by checking for any visible damage or obstructions on the conveyor

• Troubleshoot the problem by testing different components such as motors, belts, and sensors

• Repair or replace faulty parts as needed to restore the conveyor's functionality

• Ensure proper maintenance by regul...read more

There are four types of maintenance: corrective, preventive, predictive, and condition-based. Each type differs in terms of approach and timing.

• Corrective maintenance involves fixing a problem after it has occurred.

• Preventive maintenance involves scheduled inspections and maintenance to prevent problems from occurring.

• Predictive maintenance involves using data and analytics to predict when maintenance is needed.

• Condition-based maintenance involves monitoring equipment and per...read more

MCB, MCCB, ELCB are electrical protection devices used in electrical circuits.

• MCB stands for Miniature Circuit Breaker and is used for low voltage applications.

• MCCB stands for Molded Case Circuit Breaker and is used for high voltage applications.

• ELCB stands for Earth Leakage Circuit Breaker and is used to detect and protect against electrical leakage.

• All three devices are used to protect electrical circuits from overloads, short circuits, and ground faults.

I work in preventive maintenance, corrective maintenance, and predictive maintenance.

• Preventive maintenance involves routine inspections and maintenance to prevent breakdowns (e.g. changing air filters)

• Corrective maintenance is fixing issues that arise unexpectedly (e.g. repairing a broken machine)

• Predictive maintenance uses data and analytics to predict when maintenance is needed (e.g. monitoring equipment vibrations)

There are several types of transformers and bus bars used in electrical systems.

• Transformers can be classified based on their construction, voltage level, and application.

• Common types of transformers include power transformers, distribution transformers, and instrument transformers.

• Bus bars are used to distribute electrical power in a system and can be categorized as rigid or flexible.

• Examples of bus bar types include copper bus bars, aluminum bus bars, and laminated bus bars...read more

LT panel stands for Low Tension panel which is used for distributing power at low voltage levels. HT panel stands for High Tension panel which is used for distributing power at high voltage levels.

• LT panel distributes power at low voltage levels, typically up to 415V.

• HT panel distributes power at high voltage levels, typically above 415V.

• LT panels are commonly used in residential and commercial buildings.

• HT panels are used in industries and power plants for heavy machinery.

• Bo...read more

Maintenance is the process of ensuring the proper functioning and longevity of equipment, machinery, or infrastructure.

• Maintenance is required to prevent breakdowns and failures, ensuring smooth operations.

• It helps in extending the lifespan of assets and reducing the need for costly replacements.

• Regular maintenance improves safety by identifying and fixing potential hazards.

• It enhances efficiency and productivity by keeping equipment in optimal condition.

• Maintenance also incl...read more

Yes, I always follow safety rules to ensure a safe work environment.

• I always wear appropriate personal protective equipment (PPE) when working with machinery or chemicals.

• I follow lockout/tagout procedures to safely work on equipment.

• I attend regular safety training sessions to stay updated on best practices.

• I report any safety hazards or concerns to my supervisor immediately.

PM stands for Preventive Maintenance, MTTR is Mean Time To Repair, and MTBF is Mean Time Between Failures.

• PM is a proactive maintenance strategy that involves regularly scheduled maintenance to prevent equipment failure.

• MTTR is the average time it takes to repair a piece of equipment after a failure.

• MTBF is the average time between equipment failures.

• These metrics are important for measuring the effectiveness of maintenance programs and identifying areas for improvement.

• For e...read more

Regularly inspect, clean, lubricate, and repair equipment to ensure proper functioning and prevent breakdowns.

• Create a maintenance schedule for each equipment

• Inspect equipment for signs of wear and tear

• Clean equipment regularly to prevent buildup of dirt and debris

• Lubricate moving parts to reduce friction and wear

• Repair any faulty components or parts immediately

• Keep detailed records of maintenance activities

Preload is the amount of force applied to a bearing before it is put into operation. Bearing replacement involves removing the old bearing and installing a new one.

• Before installing a new bearing, clean the housing and shaft thoroughly.

• Apply a thin layer of lubricant to the bearing and shaft.

• Ensure that the bearing is properly aligned and seated in the housing.

• Tighten the fasteners to the manufacturer's recommended torque specifications.

• Check the preload and adjust if necessa...read more

ELCB stands for Earth Leakage Circuit Breaker. It is a safety device that automatically switches off the electricity supply when it detects a leakage current.

• ELCB is installed in the electrical distribution board and is connected to the earth wire of the circuit.

• It works by continuously monitoring the current flowing through the live and neutral wires of the circuit.

• If there is any imbalance in the current flow, it means that some current is leaking to the earth, and the ELCB...read more

Types of bearings include ball bearings, roller bearings, plain bearings, and fluid bearings.

• Ball bearings: use balls to reduce friction between two surfaces (e.g. deep groove ball bearings)

• Roller bearings: use cylindrical rollers to reduce friction (e.g. tapered roller bearings)

• Plain bearings: have a simple surface for sliding motion (e.g. sleeve bearings)

• Fluid bearings: use a fluid film to reduce friction (e.g. hydrodynamic bearings)

I handle wagon malfunctions by identifying the issue, troubleshooting, and repairing the problem efficiently to minimize downtime.

• Conduct a thorough inspection to identify the root cause of the malfunction

• Utilize diagnostic tools and equipment to troubleshoot the issue

• Follow maintenance manuals and guidelines for proper repair procedures

• Prioritize safety protocols while working on the wagons

• Communicate effectively with team members and supervisors to coordinate repairs

There are various types of pumps, bearings, and gears used in maintenance.

• Types of pumps include centrifugal, positive displacement, and axial flow pumps.

• Types of bearings include ball bearings, roller bearings, and sleeve bearings.

• Types of gears include spur gears, helical gears, and bevel gears.

• Each type of pump, bearing, and gear has its own unique characteristics and applications.

• It is important for maintenance technicians to have knowledge of these different types in ord...read more

PAC stands for Programmable Automation Controller, used in industrial automation for controlling processes and machinery.

• PAC is a type of industrial automation controller that combines the features of a PLC (Programmable Logic Controller) with those of a PC (Personal Computer).

• PACs are used in various industries such as manufacturing, automotive, and food processing for controlling processes and machinery.

• PACs offer advanced programming capabilities, high-speed processing, an...read more

UPS stands for Uninterruptible Power Supply, used to provide backup power during electrical outages.

• Provides backup power during electrical outages

• Protects electronic devices from power surges and fluctuations

• Ensures continuous operation of critical systems

• Commonly used for computers, servers, and other sensitive equipment

VCB stands for Vacuum Circuit Breaker, used for electrical protection by interrupting the current flow in case of a fault.

• VCB is used in high voltage electrical systems to protect equipment and personnel from damage or injury.

• It works by creating a vacuum between the contacts to extinguish the arc when the circuit is broken.

• VCBs are more reliable and require less maintenance compared to traditional circuit breakers.

• Examples of VCB manufacturers include Siemens, ABB, and Schne...read more

Safety rules for maintenance technicians are crucial to prevent accidents and injuries.

• Always wear appropriate personal protective equipment (PPE) such as gloves, safety glasses, and hard hats.

• Follow lockout/tagout procedures when working on machinery to prevent accidental startup.

• Properly store and handle hazardous materials according to safety guidelines.

• Regularly inspect tools and equipment for any defects or damage before use.

• Attend safety training sessions to stay update...read more

Following safety protocols is crucial to prevent accidents and ensure a safe work environment.

• Safety is a top priority in any workplace to protect employees from harm.

• Following safety protocols reduces the risk of accidents and injuries.

• Compliance with safety regulations can prevent costly fines and legal issues.

• Safety training and protocols help create a culture of awareness and responsibility.

• Examples: wearing proper protective gear, using equipment correctly, following eme...read more

PPE stands for Personal Protective Equipment.

• PPE is equipment worn to minimize exposure to hazards that can cause injuries or illnesses.

• Examples of PPE include gloves, goggles, helmets, and respirators.

• PPE is essential in maintaining safety in various industries such as construction, healthcare, and manufacturing.

Pneumatic systems use compressed air to transmit power, while hydraulic systems use fluid (usually oil) to transmit power.

• Pneumatic systems use compressed air as the medium for power transmission.

• Hydraulic systems use fluid (usually oil) as the medium for power transmission.

• Pneumatic systems are typically used in lighter applications, such as air brakes in vehicles.

• Hydraulic systems are used in heavier applications, such as construction equipment like excavators.

• Pneumatic sys...read more

To check an air conditioner, inspect the filters, thermostat, and refrigerant levels.

• Check the air filters and clean or replace them if necessary.

• Inspect the thermostat and ensure it is set to the desired temperature.

• Check the refrigerant levels and add more if needed.

• Inspect the condenser coils and clean them if necessary.

• Check the electrical connections and tighten any loose ones.

• Test the system by turning it on and monitoring its performance.

• Listen for any unusual noises o...read more

Maintenance is the process of ensuring that equipment, machinery, and facilities are in good working condition.

• Regular inspection and repair of equipment

• Preventive maintenance to avoid breakdowns

• Replacing worn-out parts

• Cleaning and lubricating machinery

• Ensuring safety standards are met

• Maintaining records of maintenance activities

• Responding to emergency repairs

• Continuous improvement of maintenance processes

There are many different parts in a transformer, including coils, cores, windings, bushings, tap changers, and cooling systems.

• Coils

• Cores

• Windings

• Bushings

• Tap changers

• Cooling systems

Hydraulics is a branch of science and engineering that deals with the mechanical properties of liquids, especially water.

• Hydraulics involves the study of fluid mechanics and the behavior of liquids under pressure.

• It is used in various applications such as hydraulic systems in machinery, vehicles, and aircraft.

• Hydraulic systems use fluid power to generate, control, and transmit forces and motion.

• Examples of hydraulic components include pumps, cylinders, valves, and hydraulic f...read more

Lubrication is the process of applying a lubricant to reduce friction between moving parts.

• Lubrication is essential for maintaining the performance and longevity of machinery.

• It involves applying a lubricant, such as oil or grease, to surfaces that come into contact with each other.

• The lubricant forms a thin film that separates the moving parts, reducing friction and preventing wear and tear.

• Lubrication also helps to dissipate heat generated by friction, preventing overheatin...read more

ATS stands for Automatic Transfer Switch.

• ATS is a device that automatically switches between two power sources in case of a power outage or failure.

• It ensures uninterrupted power supply to critical equipment or systems.

• For example, in a data center, an ATS can switch between utility power and backup generators.

• ATS can also be used in buildings to switch between utility power and emergency power from batteries or generators.

• It helps to prevent downtime and protect sensitive eq...read more

Safety is the state of being free from harm or danger, ensuring that proper precautions are taken to prevent accidents or injuries.

• Safety involves following proper procedures and protocols to prevent accidents.

• It includes wearing appropriate protective gear, such as helmets or gloves.

• Regular maintenance of equipment and machinery is essential for safety.

• Training employees on safety measures and emergency procedures is crucial.

• Safety inspections and audits help identify potent...read more