Reliable Steel & Plastic Industries Limited (Divine Success) Electrical Maintenance Technician Interview Questions and Answers

An overload relay works by monitoring the current flowing through a motor and tripping when the current exceeds a set limit.

• Monitors the current flowing through a motor

• Trips and interrupts power when current exceeds a set limit

• Protects the motor from damage due to overloading

• Can be reset manually after tripping

Insulation resistance is measured using a megohmmeter to apply a high voltage and measure the resistance of the insulation material.

• Use a megohmmeter to apply a high voltage to the insulation material

• Measure the resistance of the insulation material to determine its insulation resistance

• Insulation resistance is typically measured in megaohms (MΩ)

• Regular insulation resistance testing helps prevent electrical failures an

Electrical safety can be ensured by following proper procedures, using appropriate equipment, and staying vigilant.

• Always use insulated tools when working on live circuits

• Ensure circuits are de-energized before working on them

• Wear appropriate personal protective equipment (PPE) such as gloves and goggles

• Regularly inspect and maintain electrical equipment to prevent malfunctions

• Follow safety guidelines and procedures ou

Preventive maintenance on a motor involves inspecting, cleaning, lubricating, and testing the motor to ensure optimal performance and prevent breakdowns.

• Inspect the motor for any signs of wear or damage

• Clean the motor and its components to remove dirt and debris

• Lubricate moving parts to reduce friction and wear

• Test the motor's performance using appropriate tools and equipment

• Replace any worn out parts or components as

To succeed in an interview, it is important to prepare thoroughly, practice common interview questions, research the company, dress professionally, and demonstrate enthusiasm and confidence.

• Thoroughly research the company and the position you are applying for

• Practice common interview questions and prepare examples of your skills and experiences

• Dress professionally and appropriately for the interview

• Demonstrate enthusia...read more

A star-delta starter is used to reduce the starting current of a motor by initially connecting the motor windings in a star configuration and then switching to a delta configuration.

• The motor windings are initially connected in a star configuration during starting to reduce the starting current.

• After a certain period, the windings are switched to a delta configuration to achieve full speed and torque.

• This transition fr...read more

Undervoltage faults occur when the voltage in a system drops below the normal operating level, leading to potential equipment damage or malfunction.

• Undervoltage faults can be caused by issues such as power supply fluctuations, equipment failures, or overloaded circuits.

• These faults can lead to equipment damage, reduced efficiency, or complete shutdown of systems.

• Examples include a power surge causing a drop in voltage,...read more

Overvoltage faults are electrical faults that occur when the voltage in a circuit exceeds the normal operating range.

• Overvoltage faults can damage electrical components and equipment.

• They can be caused by lightning strikes, power surges, or faulty equipment.

• Protective devices like surge protectors and voltage regulators can help prevent overvoltage faults.

• Examples include a power surge from a lightning strike damaging ...read more

A thermal relay is used to protect electrical circuits from overloads by monitoring the temperature of the circuit and tripping when it exceeds a certain threshold.

• Monitors the temperature of the electrical circuit

• Trips and disconnects the circuit when temperature exceeds a set limit

• Protects against overloads and overheating

• Commonly used in motor protection applications

An RDOL starter is a type of reduced voltage starter used in electrical systems to reduce the starting current and torque of a motor.

• RDOL stands for Reduced Direct Online starter.

• It is used to start induction motors in a controlled manner.

• RDOL starters reduce the voltage supplied to the motor during starting to limit the inrush current.

• This helps in reducing mechanical stress on the motor and connected equipment.

• Common...read more

Pumps work by creating a pressure difference to move fluid from one place to another.

• Pumps use mechanical energy to increase the pressure of a fluid and move it through a system

• They can be classified into different types such as centrifugal pumps, positive displacement pumps, etc.

• The working principle involves the conversion of mechanical energy into hydraulic energy

• Examples include water pumps in buildings, fuel pumps

Cooling towers work on the principle of evaporative cooling to remove heat from a process or building.

• Cooling towers use water as a cooling medium to absorb heat from a process or building.

• The hot water is pumped to the top of the tower and distributed over the fill media.

• As the water flows over the fill media, some of it evaporates, taking away heat and cooling the rest of the water.

• The cooled water is then collected ...read more

Pollution bag filter specifications include material type, filtration efficiency, airflow capacity, and pressure drop.

• Material type: Bag filters can be made of various materials such as polyester, polypropylene, or fiberglass.

• Filtration efficiency: This indicates the percentage of particles the filter can capture. Higher efficiency filters are more effective but may have higher pressure drops.

• Airflow capacity: The maxi...read more

The formula for centrifugal pump head is H = (Q * SG) / (3.14 * D^2 * 2.31)

• Head (H) is calculated using the flow rate (Q), specific gravity (SG), and diameter of the impeller (D)

• The formula is derived from the basic equation for head in a centrifugal pump

• Example: H = (100 gpm * 1.0) / (3.14 * 0.5^2 * 2.31) = 45.75 ft

Safety refers to measures taken to prevent accidents and injuries, while hazards are potential sources of harm or danger.

• Safety involves implementing protocols and procedures to minimize risks in the workplace

• Hazards are factors or situations that have the potential to cause harm

• Examples of hazards include electrical hazards, chemical hazards, and ergonomic hazards

• Safety measures may include training employees on prope...read more

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

• Uses data analysis to predict when equipment failure is likely to occur

• Helps in scheduling maintenance activities before a breakdown occurs

• Reduces downtime and increases equipment reliability

• Examples include vibration analysis, oil analysis, and thermography