100+ Electrical Maintenance Engineer Interview Questions and Answers

Yes, I am familiar with Digital Multimeter and can demonstrate its usage for different components.

• For HV diode, set the multimeter to resistance mode and connect the probes to the diode terminals. The multimeter should show a low resistance value in one direction and high resistance in the other direction.

• For HV capacitor, set the multimeter to capacitance mode and connect the probes to the capacitor terminals. The multimeter should show the capacitance value.

• For Industrial X...read more

Proximity sensors are devices that detect the presence or absence of an object within a certain range.

• Proximity sensors use various technologies such as capacitive, inductive, ultrasonic, and optical to detect objects.

• Capacitive proximity sensors detect objects by measuring changes in capacitance when an object enters the sensor's electric field.

• Inductive proximity sensors use electromagnetic fields to detect metallic objects without physical contact.

• Ultrasonic proximity sens...read more

Connect one relay to each push button and motor, and connect the relays in parallel to the SMPS for forward and reverse operation.

• Connect one relay to each push button and motor

• Connect the relays in parallel to the SMPS

• Use the push buttons to control the relays and thus the motor direction

Power factor is a measure of how effectively electrical power is being used. It can be improved by using power factor correction techniques.

• Power factor is the ratio of real power to apparent power in an electrical system.

• It indicates the efficiency of electrical power usage.

• A power factor of 1 indicates all the power is being used effectively, while a power factor less than 1 indicates inefficiency.

• Power factor can be improved by using power factor correction techniques such...read more

There are several companies that produce PLCs. I have experience with Siemens and Allen Bradley PLCs.

• Siemens and Allen Bradley are two of the most popular PLC manufacturers

• I have experience running programs on both Siemens and Allen Bradley PLCs

• Siemens TIA Portal and Allen Bradley Studio 5000 are both user-friendly software for programming PLCs

Servo motors are used for high precision control while stepper motors are used for low speed and high torque applications.

• Servo motors have a closed-loop system while stepper motors have an open-loop system.

• Servo motors have higher accuracy and precision than stepper motors.

• Stepper motors have a higher torque output than servo motors.

• Servo motors are more expensive than stepper motors.

• Examples of servo motors include AC servo motors and DC servo motors while examples of stepp...read more

Check power supply and motor coupling

• Check if the pump is receiving power supply

• Check if the motor coupling is intact

• Check if there are any blockages in the suction line

• Check if the impeller is damaged

• Check if the pump is primed

• Check if the discharge valve is open

Power factor is the ratio of real power to apparent power in an AC circuit.

• Power factor is a measure of how effectively electrical power is being used in a circuit.

• It is calculated by dividing the real power (in watts) by the apparent power (in volt-amperes).

• A power factor of 1 indicates that all the power is being used effectively, while a power factor less than 1 indicates inefficiency.

• Low power factor can lead to increased energy costs and reduced system capacity.

• Power fac...read more

MCB is a type of source of electrical energy used for protection against overload and short circuit.

• MCB stands for Miniature Circuit Breaker.

• It is a device that automatically switches off the electrical circuit during abnormal conditions such as overload or short circuit.

• MCBs are commonly used in residential, commercial, and industrial electrical installations.

• They provide protection to electrical equipment and prevent damage or fire hazards.

• MCBs are more reliable and faster ...read more

DOL and star delta starters are used to start induction motors. PLCs can be used to control their functioning.

• DOL starter directly connects the motor to the power supply while star delta starter initially connects the motor in star configuration and then switches to delta configuration.

• PLC controlling diagram for DOL starter includes inputs for start and stop buttons, overload relay, and contactor. For star delta starter, it includes inputs for timer and contactor.

• Flow chart ...read more

Machine maintenance involves regular inspections, cleaning, lubrication, and repairs to ensure optimal performance and prevent breakdowns.

• Create a maintenance schedule to track tasks and ensure they are completed on time.

• Perform regular inspections to identify any signs of wear, damage, or malfunction.

• Clean machines regularly to remove dirt, dust, and debris that can affect performance.

• Lubricate moving parts to reduce friction and prevent excessive wear.

• Replace worn-out or da...read more

Squirrel cage induction motors have a simple and robust design, while slip ring induction motors have additional components for controlling speed and torque.

• Squirrel cage induction motors have a rotor with short-circuited conductors, while slip ring induction motors have a rotor with external resistors or brushes.

• Squirrel cage motors are commonly used in applications where constant speed is required, such as fans and pumps.

• Slip ring motors are used in applications where varia...read more

For 1.5 HP to 20 HP motors, Direct-On-Line (DOL) starters are commonly used.

• Direct-On-Line (DOL) starters are suitable for motors up to 20 HP.

• DOL starters provide a simple and cost-effective method of starting motors.

• For motors below 5 HP, a single-phase DOL starter can be used.

• For motors above 5 HP, a three-phase DOL starter is typically used.

• DOL starters directly connect the motor to the power supply, providing full voltage at start.

• Other types of starters like star-delta o...read more

The frequency of machine maintenance depends on various factors such as machine type, usage, and manufacturer's recommendations.

• Machine maintenance schedules can vary from daily, weekly, monthly, quarterly, or annually.

• Some machines may require maintenance after a certain number of operating hours or cycles.

• Manufacturer's guidelines and maintenance manuals provide specific recommendations for each machine.

• Regular maintenance helps prevent breakdowns, ensures optimal performan...read more

Yes, I am familiar with Management Information System (MIS).

• MIS is a computer-based system that provides information to support managerial decision-making.

• It collects, processes, stores, and retrieves data to generate reports and assist in planning, controlling, and decision-making processes.

• MIS helps in monitoring and analyzing various aspects of an organization, such as sales, inventory, finance, and production.

• It often includes software applications, databases, and hardwar...read more

Before 90 days, I would perform initial setup, testing, and calibration of the machine.

• Perform initial setup of the machine, including installation and configuration of electrical components.

• Conduct testing to ensure all electrical systems are functioning properly.

• Calibrate the machine to ensure accurate measurements and performance.

• Inspect and troubleshoot any potential issues or defects.

• Create a maintenance schedule and plan for regular check-ups and preventive maintenance....read more

Yes, I have knowledge of programming. FRL unit is a device used in pneumatic systems to regulate air pressure and filter out impurities.

• I am proficient in programming languages such as C++, Java, and Python.

• The FRL unit is an important component in pneumatic systems that helps to regulate air pressure and filter out impurities.

• It consists of three main parts: the filter, regulator, and lubricator.

• The filter removes impurities such as dust and dirt from the air supply.

• The regu...read more

Power is the rate at which energy is transferred. Relays are used to control high power circuits with low power signals.

• Power is measured in watts and is the product of voltage and current

• Relays are used to isolate high power circuits from low power control circuits

• Relays can also be used to switch multiple circuits with a single control signal

• Examples of relay applications include motor control, lighting control, and HVAC systems

Kaizen improvement for machine breakdown through why-why analysis and panel wiring VFD

• Perform a why-why analysis to identify the root cause of the breakdown

• Implement kaizen improvement techniques to prevent future breakdowns

• Check the panel wiring and VFD for any faults or issues

• Ensure proper maintenance and regular inspections of the machine

• Train operators and maintenance staff on proper usage and maintenance of the machine

Motors and generators are electrical machines that convert electrical energy into mechanical energy and vice versa.

• A motor is a device that converts electrical energy into mechanical energy to produce motion. It works on the principle of electromagnetic induction.

• A generator is a device that converts mechanical energy into electrical energy. It works on the principle of Faraday's law of electromagnetic induction.

• Motors and generators are used in various applications such as i...read more

A synchronisation panel for DG is used to synchronize multiple generators to ensure they are running in parallel and sharing the load evenly.

• Synchronisation panels are used in situations where multiple diesel generators need to be connected in parallel to supply power to a common bus.

• The panel monitors the frequency, voltage, and phase angle of each generator and ensures they are synchronized before connecting them to the bus.

• It also includes protection features to prevent da...read more

Transformers work on the principle of electromagnetic induction to transfer electrical energy from one circuit to another.

• Transformers consist of two coils of wire wrapped around a magnetic core.

• When an alternating current flows through the primary coil, it creates a magnetic field that induces a voltage in the secondary coil.

• This allows for the transfer of electrical energy from one circuit to another without a direct electrical connection.

• Transformers are used in industries...read more

There are several types of maintenance in electrical engineering, including preventive, corrective, predictive, and shutdown maintenance.

• Preventive maintenance involves regularly scheduled inspections, cleaning, and replacement of components to prevent breakdowns.

• Corrective maintenance is performed to fix equipment or systems that have failed or are not functioning properly.

• Predictive maintenance uses data analysis and monitoring techniques to predict when maintenance should ...read more

LOTO stands for Lockout/Tagout. It is a safety procedure used in industry and research settings to ensure that dangerous machines are properly shut off and not able to be started up again prior to the completion of maintenance or repair work.

• LOTO is a safety procedure used to prevent accidental start-up of machinery during maintenance or repair work

• It involves locking and tagging the machinery to prevent unauthorized access

• The procedure should be implemented in accordance wit...read more

VCB stands for Vacuum Circuit Breaker.

• VCB is an electrical switch that uses vacuum as the arc quenching medium.

• It is used to protect electrical equipment from overloads and short circuits.

• VCBs are commonly used in power distribution systems and industrial applications.

• They offer advantages such as high reliability, compact size, and low maintenance.

• Example: A VCB is installed in a substation to protect transformers and other equipment from electrical faults.

The cost and vendor name of CAMC (Comprehensive Annual Maintenance Contract) and AMC (Annual Maintenance Contract) for AC units vary depending on the service provider and the specific requirements of the contract.

• Cost and vendor name for CAMC and AMC can be obtained by contacting AC service providers directly.

• CAMC typically covers comprehensive maintenance services for a fixed annual fee.

• AMC usually includes regular maintenance visits and basic repairs for a yearly cost.

• Examp...read more

Regular maintenance, proper lubrication, and monitoring of operating conditions can prevent motors from breaking down easily.

• Perform regular maintenance on the motors to ensure they are in good working condition.

• Properly lubricate the motors to reduce friction and wear.

• Monitor the operating conditions of the motors, such as temperature and vibration, to detect any potential issues early on.

• Use high-quality parts and components when repairing or replacing parts.

• Train operators...read more

Servo drive and motor work together to control the position, velocity, and acceleration of a machine. CNC machines use servo systems for precise and accurate control.

• Servo drive sends signals to the servo motor to control its movement

• Servo motor converts electrical signals into mechanical motion

• Servo systems provide precise control over position, velocity, and acceleration

• CNC machines require accurate and repeatable movements, which servo systems can provide

Some common CNC M codes include M00, M01, M02, M03, M04, M05, M06, M08, M09, M30, and more.

• M00 - Program stop

• M01 - Optional stop

• M02 - Program end

• M03 - Spindle on clockwise

• M04 - Spindle on counterclockwise

• M05 - Spindle stop

• M06 - Tool change

• M08 - Coolant on

• M09 - Coolant off

• M30 - End of program

To reduce breakdown delay time, proper maintenance planning, regular inspections, and quick response to issues are necessary.

• Implement a preventive maintenance program

• Conduct regular inspections to identify potential issues

• Train maintenance staff to quickly respond to breakdowns

• Maintain an inventory of critical spare parts

• Implement a computerized maintenance management system (CMMS)

• Ensure proper documentation of maintenance activities

• Regularly review and update maintenance pr...read more

Different checks in a Diesel generator include fuel level, oil level, coolant level, battery condition, and exhaust system.

• Check fuel level and ensure there is enough fuel for operation.

• Check oil level and quality to ensure proper lubrication.

• Check coolant level and condition to prevent overheating.

• Check battery condition and connections for proper starting and charging.

• Inspect the exhaust system for leaks or blockages.

There are two main types of motors: AC motors and DC motors.

• AC motors: synchronous and asynchronous

• DC motors: brushed and brushless

• Other types: stepper, servo, linear, etc.

• Motors can also be classified by their power source, size, and application

I found vendors for different services through online research, networking events, referrals from colleagues, and industry trade shows.

• Utilized online research to find vendors offering the required services

• Attended networking events to connect with potential vendors

• Asked for referrals from colleagues in the industry

• Visited industry trade shows to discover new vendors

• Contacted industry associations for vendor recommendations

Current carrying in a conductor can be calculated using Ohm's Law, which states that current (I) equals voltage (V) divided by resistance (R).

• Use Ohm's Law: I = V / R

• Determine the voltage across the conductor

• Find the resistance of the conductor

• Calculate the current flowing through the conductor using the formula

The input value of an LT panel is the electrical power supply provided to the panel.

• The input value of an LT panel is typically the voltage and current supplied by the electrical utility.

• It can be AC (alternating current) or DC (direct current) depending on the application.

• The input value may vary depending on the specific requirements of the electrical system.

• For example, in a residential building, the input value of an LT panel may be 230V AC single-phase supply.

• In an indus...read more

There are four types of maintenance: corrective, preventive, predictive, and proactive.

• Corrective maintenance involves fixing equipment or systems after they have failed or malfunctioned.

• Preventive maintenance is performed regularly to prevent equipment or systems from failing or malfunctioning.

• Predictive maintenance uses data and analysis to predict when maintenance should be performed to prevent failures.

• Proactive maintenance involves identifying and addressing potential is...read more

BDV stands for Breakdown Voltage. It is a measure of the dielectric strength of transformer oil.

• BDV is the voltage at which the insulation between two conductors breaks down.

• It is an important parameter to determine the quality of transformer oil.

• BDV is usually measured in kilovolts (kV).

• Higher BDV indicates better quality and higher dielectric strength of the oil.

I have 8 years of experience in electrical maintenance engineering.

• I have been working as an electrical maintenance engineer for the past 8 years.

• During my career, I have gained extensive knowledge and hands-on experience in troubleshooting electrical systems and equipment.

• I have successfully completed various maintenance projects, ensuring the smooth operation of electrical systems.

• I am well-versed in conducting preventive maintenance, identifying potential issues, and imple...read more

Transformer protection system is a set of devices and techniques used to protect transformers from damage.

• It includes devices like Buchholz relay, differential relay, and overcurrent relay.

• The system detects faults and isolates the transformer from the network to prevent further damage.

• It also includes techniques like oil level monitoring and temperature monitoring.

• The protection system is essential for ensuring the reliability and longevity of transformers.

• Examples of transf...read more

Current is the flow of electric charge, while voltage is the measure of electric potential difference.

• Current is measured in amperes (A) and is the rate of flow of electric charge.

• Voltage is measured in volts (V) and is the measure of electric potential difference.

• Ohm's law relates current, voltage, and resistance: I = V/R.

• Current flows from high potential to low potential, while voltage is the difference in potential between two points.

• Examples of current include the flow of...read more

A circuit is a closed loop of conductive material that allows electricity to flow. A switch is a device that controls the flow of electricity in a circuit.

• A circuit is made up of a power source, conductive material, and a load.

• Electricity flows from the power source through the conductive material and into the load.

• A switch is used to open or close the circuit, controlling the flow of electricity.

• Switches can be manual or automatic, and can be used to turn on or off lights, m...read more

To check motor healthiness, perform visual inspection, measure electrical parameters, check for abnormal noises and vibrations, and conduct insulation resistance tests.

• Perform a visual inspection of the motor for any signs of damage, such as burnt wires or loose connections.

• Measure electrical parameters like voltage, current, and resistance to ensure they are within the motor's specifications.

• Check for abnormal noises or vibrations during motor operation, which could indicate...read more

Pulse width in laser refers to the duration of time that a laser beam is emitted.

• Pulse width is measured in seconds or milliseconds.

• It determines the amount of energy delivered by the laser beam.

• Shorter pulse widths are often used for precision cutting or welding.

• Longer pulse widths are used for applications like material processing or drilling.

Dry service involves cleaning the AC unit without using water, while wet service involves cleaning with water and chemicals.

• Dry service involves cleaning the AC unit using a vacuum cleaner, brushes, and compressed air to remove dust and debris.

• Wet service involves cleaning the AC unit using water, cleaning agents, and chemicals to remove dirt, mold, and bacteria.

• Dry service is recommended for regular maintenance to prevent dust buildup, while wet service is recommended for de...read more

I handle an area of approximately 10,000 square feet.

• I am responsible for the electrical maintenance of a facility that covers 10,000 square feet.

• The area I handle includes various electrical systems and equipment within a 10,000 square foot space.

• I ensure the proper functioning and maintenance of electrical systems in a facility spanning 10,000 square feet.

Daily electrical problems in our company include power outages, equipment malfunctions, and faulty wiring.

• Power outages due to grid failures or equipment overload

• Equipment malfunctions such as motor burnouts or circuit breaker trips

• Faulty wiring causing short circuits or electrical shocks

• Issues with electrical panels or transformers

• Problems with lighting systems or electrical outlets

Types of maintenance include corrective, preventive, predictive, and proactive. A transformer is an electrical device that transfers energy between circuits.

• Corrective maintenance involves fixing a problem after it occurs.

• Preventive maintenance involves regularly scheduled maintenance to prevent problems from occurring.

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

• Proactive maintenance involves identifying and fixing potential problems befor...read more