50+ Burns & McDonnell Interview Questions and Answers

Cable sizing is calculated using the formula for voltage drop, which takes into account resistive and inductive drop. Voltage drop is limited to 5% to ensure efficient power transmission.

• Cable sizing is determined by calculating the voltage drop using the formula: VD = (I * L * R * 2) / 1000

• Resistive drop is calculated using Ohm's Law: Vr = I * R

• Inductive drop is calculated using the formula: Vi = I * X

• Voltage drop is limited to 5% to prevent excessive power loss and ensure e...read more

Explanation of lighting calculation, light loss factor, utilisation factor, and minimum lux required in substation.

• Lighting calculation involves determining the amount of light required in a space.

• Light loss factor is the reduction in light output due to factors such as dirt, dust, and aging of lamps.

• Utilisation factor is the ratio of light received by a surface to the total light output of the lamps.

• Formula for lighting calculation: Total light output = Area x Required lux l...read more

Percentage Impedance is a measure of the voltage drop in a transformer during a short circuit. It determines the ability of the transformer to withstand short circuit currents.

• Percentage Impedance is the ratio of the rated voltage of a transformer to the short circuit current at its terminals, expressed as a percentage.

• It represents the internal impedance of the transformer and is usually provided by the manufacturer.

• A higher percentage impedance means a higher voltage drop d...read more

The input required for a single line diagram includes information about the electrical system components and their connections.

• Information about the electrical system components such as generators, transformers, switchgear, and loads

• The connections between these components including the type of connection and the ratings of the equipment

• The voltage level of the system and the type of system grounding

• The protective devices such as circuit breakers and fuses

• Any special requirem...read more

Non-linear loads are electrical devices that do not have a linear relationship between the voltage and current.

• Non-linear loads draw non-sinusoidal current waveforms.

• They can cause harmonic distortion in the electrical system.

• Examples of non-linear loads include computers, televisions, and variable speed drives.

• Linear loads have a linear relationship between voltage and current, such as incandescent light bulbs.

• Linear loads do not cause harmonic distortion.

1.25 FLA is taken for circuit breaker and 1.5 times for contactor to ensure protection against overloading and short circuits.

• 1.25 FLA is the maximum current that a circuit breaker can handle without tripping.

• 1.5 times FLA is taken for contactor to ensure that it can handle the inrush current during motor starting.

• This also provides protection against short circuits and overloading.

• For example, if the full load current of a motor is 10A, then a circuit breaker rated for 12.5A...read more

Hazardous area classification involves categorizing areas based on the presence of flammable gases, vapors, or dusts.

• Hazardous areas are classified based on the likelihood of the presence of flammable substances.

• Temperature Class refers to the maximum surface temperature of equipment that can be used in a hazardous area.

• Hazardous areas are categorized into zones based on the frequency and duration of the presence of flammable substances.

• Examples of hazardous areas include oil...read more

Earthing calculation standards and resistances for substation and lightning protection.

• Earthing calculation involves determining the resistance of the earth electrode system.

• The standard used for earthing calculation is IEEE 80.

• The resistance in substation should be less than 1 ohm.

• The resistance for lightning protection should be less than 10 ohms.

• Factors affecting earthing calculation include soil resistivity, electrode material, and electrode spacing.

• Earthing calculation i...read more

Types of contactors include AC, DC, reversing, and definite purpose. Maximum efficiency of transformer depends on load and design.

• AC contactors are used for alternating current circuits

• DC contactors are used for direct current circuits

• Reversing contactors are used to reverse the direction of current flow

• Definite purpose contactors are designed for specific applications

• Maximum efficiency of transformer is achieved at full load

• Efficiency is affected by design factors such as co...read more

Motor feeder and power feeder requirements are essential for electrical design engineers to ensure proper functioning of electrical systems.

• Motor feeder requirements include selecting the appropriate motor size, voltage, and current rating.

• Power feeder requirements involve determining the load requirements and selecting the appropriate cable size and voltage drop.

• Proper coordination and protection devices such as circuit breakers and fuses must be selected for both motor and ...read more

The motor contribution to the short circuit current is significant and needs to be considered in electrical design.

• The motor's impedance affects the short circuit current level.

• The motor's starting current can cause a significant increase in short circuit current.

• The motor's location in the electrical system can affect its contribution to the short circuit current.

• The motor's size and type can also impact its contribution to the short circuit current.

• Proper coordination and p...read more

APFC stands for Automatic Power Factor Correction. Series reactor is a device used to limit current flow.

• APFC is a system that automatically corrects the power factor of an electrical network.

• It uses capacitors to improve the power factor and reduce energy consumption.

• Series reactor is a device that is used to limit the flow of current in a circuit.

• It is used to protect equipment from overvoltage and to reduce harmonics in the system.

• An example of series reactor is a line rea...read more

Protection schemes for transformers and generators.

• Overcurrent protection

• Differential protection

• Distance protection

• Restricted earth fault protection

• Backup protection

• Buchholz relay protection

• Thermal overload protection

• Under/over voltage protection

• Neutral grounding protection

The 14 points of the DCMA are guidelines for effective project management in defense contracts.

• Establish clear project objectives and requirements

• Develop a realistic project schedule

• Assign responsibilities and authorities clearly

• Ensure adequate resources are available

• Maintain open communication with stakeholders

• Identify and manage project risks

• Monitor and control project performance

• Implement corrective actions when necessary

• Ensure compliance with regulations and standards

• Docu...read more

Formulas used to calculate Budget at Completion (BAC) in project control engineering.

• BAC = Planned Value (PV) at completion

• BAC = Actual Cost (AC) + Estimate to Complete (ETC)

• BAC = Budgeted Cost of Work Scheduled (BCWS) + Budgeted Cost of Work Remaining (BCWR)

Cable tray layout involves designing and arranging cable trays for efficient cable management.

• Input requirements include cable type, size, weight, and routing

• Trench layout input requirements include trench dimensions and depth

• Design should consider cable spacing, support, and accessibility

• Proper grounding and bonding should also be considered

Different types of relationships include familial, romantic, professional, and platonic relationships.

• Familial relationships: relationships between family members such as parents, siblings, and children.

• Romantic relationships: intimate relationships between partners or spouses.

• Professional relationships: relationships between colleagues or business partners.

• Platonic relationships: non-romantic relationships based on friendship and mutual respect.

Steps to create a look-ahead report

• Identify the project milestones and deadlines

• Review the project schedule and identify upcoming tasks

• Analyze potential risks and delays

• Update the look-ahead report with current progress and forecasted completion dates

• Communicate the report to stakeholders for awareness and decision-making

Yes, 3 Phase autoreclosure can be used at 400KV line with pros and cons.

• Pros: Improved system reliability, reduced outage duration, automatic fault clearing

• Cons: Increased wear on equipment, potential for re-ignition of faults, coordination challenges with other protection devices

Primavera is a project management software used for planning, scheduling, and controlling projects.

• Primavera is commonly used in industries such as construction, engineering, and manufacturing.

• It allows users to create project schedules, allocate resources, track progress, and analyze project performance.

• Users can generate reports, monitor costs, and manage risks within the software.

• Primavera offers features like Gantt charts, critical path method, and resource leveling.

• It he...read more

Key performance indicators are measurable values that demonstrate how effectively a company is achieving key business objectives.

• KPIs are specific, quantifiable metrics used to track progress towards organizational goals.

• They help in evaluating the success of a project or business by measuring performance in key areas.

• Examples of KPIs for a Project Control Engineer may include project completion time, budget variance, and quality control metrics.

Earned value management is a project management technique for measuring project performance and progress.

• Compares actual work completed and costs incurred to planned work and costs

• Helps in forecasting project outcomes based on current performance

• Key metrics include Planned Value (PV), Earned Value (EV), and Actual Cost (AC)

• Formula: EV = % of work completed * Total budget

• Example: If a project is 50% complete and the total budget is $100,000, EV = 50% * $100,000 = $50,000

A schedule can be created by identifying project tasks, estimating durations, sequencing tasks, assigning resources, and setting milestones.

• Identify all project tasks and break them down into smaller, manageable activities.

• Estimate the duration of each task based on historical data or expert judgment.

• Sequence the tasks in the order they need to be completed, considering dependencies between tasks.

• Assign resources to each task, taking into account availability and skill level....read more

Orifice std refers to standard orifice sizes used in engineering. Types of taps include flange taps, corner taps, and D and D/2 taps.

• Orifice std refers to standard sizes of orifices used in flow measurement

• Types of taps include flange taps, corner taps, and D and D/2 taps

• Flange taps are used for large pipes, corner taps for small pipes, and D and D/2 taps for general applications

The typical deliverables of a project engineer include design drawings, technical specifications, project schedules, cost estimates, and progress reports.

• Design drawings: detailed plans and schematics for construction or manufacturing

• Technical specifications: detailed requirements for materials, equipment, and processes

• Project schedules: timelines for completing tasks and milestones

• Cost estimates: budget projections for labor, materials, and other expenses

• Progress reports: up...read more

Straight length requirements for orifice flow element ensure accurate measurement by allowing flow to stabilize before reaching the element.

• Straight length requirements typically range from 10 to 44 pipe diameters upstream and 5 to 22 pipe diameters downstream of the orifice.

• These requirements help prevent flow disturbances and ensure accurate measurement of flow rate.

• For example, if the pipe diameter is 4 inches, the straight length requirements upstream could be 40 to 176 i...read more

Motor starters are used to control the starting and stopping of motors in various applications.

• Motor starters help protect motors from overloads and short circuits.

• They provide a convenient way to start and stop motors remotely.

• Motor starters can also provide under-voltage and over-voltage protection to the motors.

• Examples of applications include industrial machinery, HVAC systems, and water pumps.

The power triangle represents the relationship between real power, reactive power, and apparent power in an AC circuit.

• The power triangle is a visual representation of the relationship between real power (P), reactive power (Q), and apparent power (S) in an AC circuit.

• Real power (P) is the actual power consumed by the circuit and is measured in watts (W).

• Reactive power (Q) is the power that flows back and forth between the source and the load due to inductive or capacitive el...read more

A look-ahead report is a document that outlines upcoming tasks, potential issues, and solutions for a project.

• Provides a snapshot of upcoming project activities

• Highlights potential roadblocks and proposed solutions

• Helps project team anticipate and plan for future challenges

• Usually covers a short-term period, such as the next week or month

Pressure gauge operating range refers to the minimum and maximum pressure values that the gauge can accurately measure.

• Pressure gauge operating range is typically specified by the manufacturer.

• It is important to ensure that the pressure being measured falls within the gauge's operating range to ensure accurate readings.

• For example, a pressure gauge with an operating range of 0-100 psi should not be used to measure pressures outside of this range.

Types of circuit breakers used in substations include air circuit breakers, oil circuit breakers, vacuum circuit breakers, and SF6 circuit breakers.

• Air circuit breakers are commonly used in low voltage applications.

• Oil circuit breakers are used in high voltage applications.

• Vacuum circuit breakers are compact and reliable, suitable for medium voltage applications.

• SF6 circuit breakers are used in high voltage substations for their excellent arc quenching properties.

1 phase AR is not used in 132KV lines due to limitations in fault detection and protection coordination.

• 1 phase AR lacks fault detection capabilities for all three phases

• Coordination with other protection devices becomes difficult with 1 phase AR

• Risk of incorrect tripping due to lack of complete system information

• Potential for increased downtime and damage to equipment in case of faults

Model reviews typically include checking for accuracy, completeness, consistency, and compliance with standards.

• Checking accuracy of dimensions and specifications

• Ensuring completeness of all required components and features

• Verifying consistency in design and documentation

• Confirming compliance with industry standards and regulations

Layout details of support type equipment in previous project

• Support type equipment included pipe supports, hangers, and anchors

• Layout involved determining locations for supports based on piping design and stress analysis

• Consideration given to weight, thermal expansion, and vibration of piping system

• Supports were designed to ensure proper alignment and stability of piping system

Dead time of 1 second is commonly used in protection systems to allow for accurate fault detection and coordination.

• Dead time of 1 second is a standard value used in protection systems to account for relay operation time and communication delays.

• It helps prevent false tripping by allowing for transient conditions to stabilize before initiating a trip.

• For example, in a distance relay setting, a dead time of 1 second ensures that the relay does not trip for temporary faults or ...read more

Reclaim time is 25 seconds to ensure proper coordination and selectivity of protection devices.

• Reclaim time is set to allow downstream protective devices to clear faults before the upstream device operates.

• It helps in preventing unnecessary tripping of healthy parts of the system.

• The 25-second reclaim time is a standard value used in protection coordination studies.

• Adjusting the reclaim time can impact the selectivity and coordination of protection devices.

IS 456 is the code used for RCC (Reinforced Cement Concrete) in India.

• IS 456 is the Indian Standard code for the design and construction of reinforced concrete structures.

• It provides guidelines for the selection of materials, mix design, construction practices, and quality control.

• For example, IS 456 specifies the minimum grade of concrete, minimum cover to reinforcement, and detailing requirements for RCC structures.

Control valve sizing requires accurate input data to ensure proper valve selection and performance.

• Process fluid properties such as density, viscosity, and pressure drop

• Flow rate and flow characteristics

• Piping and valve specifications

• Control system requirements

• Environmental factors such as temperature and altitude

• Consideration of safety and reliability

• Examples of input data include P&ID diagrams, process data sheets, and equipment specifications

A wave trap is a device used in electrical engineering to prevent unwanted signals or frequencies from entering a system.

• Wave traps are typically used in power systems to filter out specific frequencies that can cause interference.

• They are designed to allow only desired signals to pass through while blocking unwanted signals.

• Wave traps can be used in substations, transmission lines, and other electrical systems to improve overall system performance.

• Examples of wave traps incl...read more

SPI modules are communication interfaces used to transfer data between microcontrollers and peripheral devices.

• SPI stands for Serial Peripheral Interface

• It is a synchronous communication protocol

• SPI modules have a master-slave architecture

• Data is transferred in full duplex mode

• Commonly used in microcontroller-based systems for communication with sensors, displays, and memory devices

Stress strain diagram shows the relationship between stress and strain in a material.

• The stress strain diagram typically consists of a linear elastic region, a yield point, plastic deformation, and ultimate failure.

• The slope of the linear elastic region represents the material's modulus of elasticity.

• The yield point indicates the point at which the material begins to deform plastically.

• The area under the stress strain curve represents the energy absorbed by the material durin...read more

Contact candidate to understand reasons for rejection, provide feedback, and keep communication open for future opportunities.

• Contact the candidate to understand their reasons for rejecting the offer

• Provide feedback on the interview process or offer to improve future interactions

• Keep communication open for potential future opportunities with the candidate

Designing RCC footing, column, purlins, SFD, and BMD for oil and gas projects.

• RCC footing design involves determining the size and reinforcement of the foundation to support the load of the structure.

• RCC column design includes calculating the dimensions and reinforcement required to withstand the vertical loads.

• Purlins are horizontal structural members used to support the roof covering and transfer loads to the columns.

• SFD (Shear Force Diagram) and BMD (Bending Moment Diagram...read more

I have experience working with ETAP on various projects, including designing power systems and conducting load flow analysis.

• Designed power distribution systems using ETAP software

• Conducted load flow analysis to optimize system performance

• Implemented protective device coordination studies to ensure system reliability

• Worked on projects involving power system modeling and simulation

System studies involve analyzing and evaluating the performance of electrical systems to ensure efficiency and reliability.

• System studies involve analyzing the behavior of electrical systems under different operating conditions.

• They help identify potential issues and optimize the performance of the system.

• Examples of system studies include load flow analysis, short circuit analysis, and protection coordination studies.

Load flow study is a method used in electrical engineering to analyze and calculate the flow of power in an electrical network.

• Load flow study helps in determining the steady-state operating conditions of a power system.

• It involves calculating the voltage magnitude and phase angle at each bus in the network.

• The study considers factors like power generation, transmission line losses, and load demand.

• It helps in identifying potential issues such as voltage instability, overload...read more

Different transformer protection methods include overcurrent protection, differential protection, and distance protection.

• Overcurrent protection: Protects against overloads and short circuits by tripping the circuit breaker when current exceeds a certain threshold.

• Differential protection: Compares the current entering and leaving the transformer to detect internal faults.

• Distance protection: Uses impedance measurements to determine the location of a fault and isolate it from ...read more

Variable frequency drive (VFD) controls the speed of an electric motor by varying the frequency and voltage of the power supplied to it.

• VFDs are commonly used in industrial applications to control the speed of pumps, fans, compressors, and other motor-driven equipment.

• They work by converting fixed frequency AC power to variable frequency AC power using semiconductor devices.

• VFDs can improve energy efficiency, reduce wear and tear on equipment, and provide precise control over...read more

Design steps of foundation involve site investigation, soil testing, foundation type selection, structural design, and construction.

• Site investigation to assess soil conditions and load-bearing capacity

• Soil testing to determine soil properties and behavior under load

• Selection of appropriate foundation type based on soil conditions and structural requirements (e.g. shallow foundation, deep foundation)

• Structural design of foundation to ensure stability and safety

• Construction of...read more

Design steps of the slab involve determining the type of slab, calculating loads, selecting materials, and detailing reinforcement.

• Determine the type of slab based on the structural requirements and architectural design.

• Calculate the loads that the slab will be subjected to, including dead loads, live loads, and other imposed loads.

• Select appropriate materials for the slab, considering factors such as strength, durability, and cost.

• Detail the reinforcement layout of the slab,...read more

The project lifecycle is the series of phases a project goes through from initiation to completion.

• Initiation: Define project goals, scope, and stakeholders

• Planning: Create a detailed project plan, schedule, and budget

• Execution: Implement the project plan and deliver the project

• Monitoring and Controlling: Track progress, manage changes, and ensure quality

• Closing: Finalize all project activities and hand off deliverables to stakeholders

Speed control of a motor is achieved by varying the voltage or frequency of the power supply.

• Speed control can be achieved by adjusting the voltage supplied to the motor.

• Alternatively, the frequency of the power supply can be varied to control the speed.

• Using a variable frequency drive (VFD) allows for precise control of motor speed.

• Feedback control systems can be implemented to maintain a constant speed under varying load conditions.