20+ Deputy Manager Maintenance Interview Questions and Answers

The strength of maintenance team, defining cooling tower capacity, plant layout, crane capacity, transformer capacity, and knowledge of LT panel safety checks.

• The strength of the maintenance team can be defined by their experience, skills, and ability to work together efficiently.

• The capacity of the cooling tower can be determined by calculating the heat load of the plant and the required cooling capacity.

• Plant layout should be designed to optimize the flow of materials and p...read more

The interviewer asked about material conveying system, hopper dryer, dehumidifier, chiller, injection molding machine grading, number of pillars, and backflow.

• Material conveying system is operational with X number of hopper dryers and dehumidifiers and Y make of chiller.

• Injection molding machine has a grading of Z and there are N pillars.

• Backflow data is not available.

Yes, I have experience in removing and assembling centrifugal mechanical seal pumps.

• I have experience in removing and assembling centrifugal mechanical seal pumps.

• I am familiar with the tools and techniques required for the job.

• I have successfully completed similar tasks in my previous roles.

• I am confident in my ability to perform the task efficiently and effectively.

The selection of transformer delta/star configuration in the main grid offers cost savings and simplifies the protection system requirements.

• Delta/star configuration reduces the cost of the transformer as it requires fewer windings compared to a star/star configuration.

• Delta/star transformers are commonly used in high-voltage transmission systems where cost optimization is crucial.

• The delta configuration provides better fault tolerance and can handle unbalanced loads effectiv...read more

Earthing voltage for Neutral to earth point is typically zero in a properly functioning electrical system.

• In a properly functioning electrical system, the earthing voltage for Neutral to earth point is typically zero.

• The purpose of earthing is to provide a path for fault currents to safely dissipate into the ground, preventing electric shocks and fires.

• If the earthing voltage is not zero, it could indicate a fault in the system that needs to be addressed immediately.

• Regular t...read more

Lightning impulse test of a power transformer is a high voltage test to simulate lightning strikes and ensure the transformer can withstand sudden voltage surges.

• It is a high voltage test conducted to simulate lightning strikes on the transformer

• The test is performed to ensure the transformer can withstand sudden voltage surges

• It helps in evaluating the insulation strength and overall performance of the transformer

• The test involves applying a high voltage impulse to the trans...read more

650kVp is chosen for lighting impulse level for 132kV due to its ability to withstand lightning strikes and protect the equipment.

• 650kVp is a standard value chosen based on the insulation level required for 132kV systems

• Lightning impulse level is selected to ensure equipment can withstand lightning strikes without damage

• Higher impulse levels provide better protection against lightning-induced surges

• Choosing the right impulse level is crucial for ensuring the reliability and s...read more

CFM stands for Continuous Flow Manufacturing, a production strategy focused on continuous and efficient production processes.

• CFM aims to minimize waste and maximize efficiency by continuously moving products through the production process.

• It involves the use of automation and just-in-time inventory management to streamline operations.

• Examples of companies using CFM include Toyota and Dell, known for their efficient production processes.

• CFM is often associated with lean manufa...read more

Safety controls in press machines include guards, emergency stop buttons, and safety light curtains.

• Guards prevent access to hazardous areas of the machine

• Emergency stop buttons immediately shut down the machine in case of an emergency

• Safety light curtains use sensors to detect when a person or object is in the danger zone and stop the machine

• Other safety controls may include interlocks, warning signs, and personal protective equipment

The highest efficiency of a transformer is achieved at 60% loading.

• Efficiency of a transformer is the ratio of output power to input power.

• At 60% loading, the transformer operates closer to its rated capacity, resulting in higher efficiency.

• Operating a transformer at lower or higher loadings can decrease its efficiency.

• Efficiency can be improved by using high-quality materials and reducing losses in the transformer.

• For example, a transformer rated for 1000 kVA would have its ...read more

The size of the filter in a hydraulic system depends on the flow rate and pressure requirements of the system.

• The size of the filter is typically measured in microns, with common sizes ranging from 5 to 100 microns.

• The size of the filter should be selected based on the cleanliness requirements of the hydraulic fluid and the flow rate of the system.

• A larger filter size (e.g. 100 microns) will allow for higher flow rates but may not provide as fine filtration as a smaller filte...read more

Speed control of an AC machine is achieved by varying the frequency of the input power supply.

• Speed control is typically done using a variable frequency drive (VFD) which adjusts the frequency of the input power to the motor.

• By increasing or decreasing the frequency, the motor speed can be controlled without changing the number of poles in the motor.

• For example, in an industrial setting, a VFD may be used to control the speed of a conveyor belt or a pump motor.

• Speed control i...read more

Heat run test of transformer is a test conducted to assess the performance of a transformer under normal operating conditions.

• Heat run test involves running the transformer at full load for a specified period of time to evaluate its temperature rise.

• The test helps in determining if the transformer can handle the heat generated during normal operation without overheating.

• It is essential to ensure that the transformer can operate efficiently and safely under varying load condit...read more

Voltage rating in multiples of 11 is common due to historical reasons and practical considerations.

• Historically, early power systems used 110V and 220V as standard voltages.

• Multiples of 11 make it easier to design transformers and other electrical equipment.

• Standardizing on multiples of 11 simplifies the distribution and transmission of power.

• Common voltage ratings like 110V, 220V, 440V, etc., are all multiples of 11.

I have experience in maintaining and troubleshooting HVAC systems.

• Performed regular maintenance checks on HVAC equipment

• Identified and repaired faulty components in HVAC systems

• Implemented energy-saving measures to improve efficiency

• Collaborated with HVAC technicians to resolve complex issues

Types of compressors include reciprocating, rotary screw, centrifugal, and scroll compressors.

• Reciprocating compressors use pistons to compress air.

• Rotary screw compressors use two rotating screws to compress air.

• Centrifugal compressors use a rotating impeller to compress air.

• Scroll compressors use two interleaving scrolls to compress air.

A single line diagram is a simplified representation of an electrical system showing the main components and their connections.

• Shows main components like generators, transformers, switchgear, etc.

• Uses standardized symbols to represent different elements.

• Helps in understanding the flow of electricity and identifying key components.

• Does not show detailed wiring or physical locations of components.

• Used for planning, designing, and troubleshooting electrical systems.

An induction machine is an AC electric motor in which the electric current in the rotor needed to produce torque is induced by electromagnetic induction from the magnetic field of the stator winding.

• Induction machines are commonly used in various industrial applications for their simplicity, reliability, and low maintenance requirements.

• They operate on the principle of electromagnetic induction, where a rotating magnetic field in the stator induces current in the rotor, causi...read more

Three phase voltage is a type of electrical power transmission that utilizes three alternating currents.

• Three phase voltage consists of three alternating currents that are 120 degrees out of phase with each other.

• It is commonly used in industrial and commercial settings for powering large equipment and machinery.

• The voltage between any two phases in a three phase system is higher than the voltage of any one phase to neutral.

• Examples of three phase voltage systems include 208V...read more

I am familiar with various softwares including CMMS, CAD, and Microsoft Office Suite.

• CMMS (Computerized Maintenance Management System)

• CAD (Computer-Aided Design)

• Microsoft Office Suite

WHY-WHY analysis reports are used to identify the root cause of a problem and prevent its recurrence.

• WHY-WHY analysis helps in identifying the underlying causes of a problem by asking 'why' multiple times.

• It helps in preventing the recurrence of the problem by addressing the root cause.

• It is a structured approach to problem-solving and decision-making.

• Example: If a machine breaks down, asking 'why' multiple times can help identify the root cause, such as lack of maintenance o...read more

A generator is a device that converts mechanical energy into electrical energy.

• Generators are commonly used as backup power sources during power outages.

• They can be powered by various sources such as gasoline, diesel, natural gas, or renewable energy sources like solar or wind.

• Generators come in different sizes and capacities to meet different power needs.

• They consist of an engine, alternator, fuel system, voltage regulator, cooling and exhaust systems, and control panel.

Real ground fact of machines refers to the actual condition and performance of machines in operation.

• Real ground fact of machines can be determined through regular maintenance checks and monitoring of machine performance.

• It involves assessing factors such as machine uptime, downtime, efficiency, and any recurring issues or breakdowns.

• Examples of real ground facts of machines include tracking the number of maintenance interventions needed, analyzing machine failure patterns, a...read more