90+ Electrical Site Engineer Interview Questions and Answers

The maximum range of voltage rating for belted cables varies depending on the specific application and industry standards.

• The voltage rating of belted cables can range from low voltage (LV) to high voltage (HV).

• LV belted cables typically have a voltage rating of up to 1 kV.

• HV belted cables can have voltage ratings ranging from 1 kV to several hundred kilovolts (kV).

• The exact voltage rating of belted cables is determined by factors such as insulation material, conductor size, ...read more

Cable protectors can safeguard cables against mechanical injury.

• Cable protectors can be used to cover and shield cables from physical damage.

• Flexible conduits or cable trays can be installed to provide a protective pathway for cables.

• Using cable ties or clamps to secure cables in place can prevent them from being accidentally pulled or strained.

• Applying cable armor or armored cables can provide additional protection against impact or crushing.

• Using cable guards or ramps can p...read more

The torque a synchronous motor can develop depends on its size and design.

• The torque is directly proportional to the current supplied to the motor.

• The torque also depends on the strength of the magnetic field produced by the rotor.

• Larger synchronous motors can develop higher torque than smaller ones.

• For example, a 500 kW synchronous motor can develop a torque of around 1500 Nm.

• The torque can also be affected by factors such as temperature and load conditions.

A transformer is a static device that uses mutual induction to convert voltage levels.

• Transformers are used to increase or decrease the voltage in electrical circuits.

• They consist of two or more coils of wire, known as windings, that are wound around a core.

• The primary winding is connected to the input voltage source, while the secondary winding is connected to the load.

• When an alternating current flows through the primary winding, it creates a changing magnetic field in the ...read more

Three phase voltage is not simply the sum of single phase voltages due to different configurations and power distribution requirements.

• Three phase power systems are designed to be more efficient and balanced compared to single phase systems.

• In a three phase system, the voltage between any two phases is 440V, not the sum of single phase voltages (220V).

• The total power in a three phase system is proportional to the square root of 3, hence the voltage is not simply tripled.

• Highe...read more

Conventional flow assumes charges flow from positive to negative terminals.

• Conventional flow is based on the assumption that current flows from positive to negative terminals.

• This convention is used in electrical engineering and circuit analysis.

• For example, in a battery-powered circuit, conventional flow assumes that electrons flow from the positive terminal of the battery to the negative terminal.

A circuit breaker is an electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit.

• Circuit breakers automatically detect faults in the electrical system and interrupt the flow of electricity to prevent damage.

• They come in different types such as thermal-magnetic, magnetic, and hydraulic-magnetic circuit breakers.

• Common examples include miniature circuit breakers (MCB), molded case circuit breakers (MCCB), and residual current c...read more

The average resistance of a human body is approximately 1,000 ohms.

• The resistance of a human body can vary depending on factors such as skin moisture, contact area, and voltage applied.

• Dry skin has higher resistance compared to moist skin.

• The resistance can be affected by the presence of sweat, water, or other conductive substances on the skin.

• The resistance decreases when the contact area between the body and a conductive surface increases.

• The average resistance of a human b...read more

Resistance connected to a source voltage in series will affect the current flowing through the circuit.

• Increases the total resistance in the circuit

• Decreases the total current flowing through the circuit

• Causes a voltage drop across the resistor

• Can be calculated using Ohm's Law: V = I * R

The earth wire or ground wire is typically made of copper or aluminum.

• The earth wire is an essential safety component in electrical systems.

• It is used to provide a path for electrical current to safely discharge into the ground.

• Copper is commonly used for earth wires due to its excellent conductivity and corrosion resistance.

• Aluminum is also used in some cases, especially for overhead power lines.

• The earth wire is usually connected to a grounding electrode, such as a metal ro...read more

To protect oneself from an electric shock, one should follow safety precautions and use proper equipment.

• Always turn off the power source before working on electrical equipment

• Use insulated tools and wear rubber gloves when working with live wires

• Avoid working in wet conditions or with wet hands

• Install Ground Fault Circuit Interrupters (GFCIs) in areas where water is present

• Regularly inspect and maintain electrical equipment to prevent malfunctions

• Educate yourself on electric...read more

A site engineer is responsible for overseeing and managing electrical construction projects on-site.

• Supervising and coordinating electrical installation and maintenance activities

• Ensuring compliance with electrical codes, regulations, and safety standards

• Reviewing and interpreting electrical drawings and specifications

• Managing project schedules and budgets

• Collaborating with contractors, architects, and other stakeholders

• Troubleshooting electrical issues and providing technica...read more

AC motors use alternating current while DC motors use direct current. AC motors are more commonly used due to their simplicity and efficiency.

• AC motors use alternating current, while DC motors use direct current

• AC motors are more commonly used in household appliances and industrial applications

• DC motors are often used in small applications like toys and tools

• AC motors are simpler in construction and more efficient than DC motors

The current used in laptops, mobiles, and electronic devices is typically low voltage direct current (DC).

• Laptops, mobiles, and electronic devices operate on low voltage DC power.

• The current used is usually in the range of 1-2 Amps.

• The power adapters or chargers convert AC power from the wall outlet to DC power for these devices.

• The DC current is used to power the internal components and charge the batteries.

• Examples of current ratings for laptops and mobiles are 1.5A, 2A, et...read more

To generate 10 kW, you would need approximately 30 330W cells.

• Calculate the total power output required: 10 kW = 10,000 watts

• Determine the number of cells needed by dividing the total power output by the power output of each cell: 10,000 watts / 330 watts = 30 cells

• Therefore, approximately 30 330W cells are required for a 10 kW generation plant

Transmission lines are typically designed for higher voltages like 110 kV, 220 kV, 400 kV, and above due to efficiency and cost considerations.

• Transmission lines are designed for higher voltages to reduce energy losses during transmission.

• Higher voltages allow for longer transmission distances without significant power loss.

• Higher voltage transmission lines are more cost-effective compared to lower voltage lines for long-distance power transmission.

• Standard transmission line ...read more

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

• LOTO involves isolating energy sources, locking them out, and tagging them to indicate that maintenance work is being performed.

• Workers involved in the maintenance work are the ones who apply the locks and tags, ensuring their safety.

• Before starting work, a thorough inspection is...read more

Earthing method involves connecting electrical equipment to the earth to prevent electric shock and damage to equipment.

• Earthing can be done through a rod, plate, or strip depending on the soil resistivity

• Tray types include ladder, perforated, solid-bottom, and wire mesh

• Testing of equipment involves checking insulation resistance, continuity, and polarity

• Panel testing includes checking for loose connections, proper labeling, and correct breaker sizing

In series connection, voltage increases while current remains the same. In parallel connection, current increases while voltage remains the same.

• In series connection, the total voltage is the sum of individual voltages (Vtotal = V1 + V2).

• In series connection, the total current remains the same as the individual currents (Itotal = I1 = I2).

• In parallel connection, the total current is the sum of individual currents (Itotal = I1 + I2).

• In parallel connection, the total voltage re...read more

Light calculations involve determining illuminance, luminous flux, and luminous intensity for proper lighting design.

• Calculate illuminance (lux) by dividing luminous flux (lumens) by area (square meters)

• Determine luminous intensity (candela) by dividing luminous flux (lumens) by solid angle (steradians)

• Consider factors like reflectance, room shape, and light distribution for accurate calculations

• Use lighting software or photometric data for complex calculations

• Example: To cal...read more

A transformer is a device that transfers electrical energy between two or more circuits through electromagnetic induction. A relay is an electrically operated switch. A motor is a machine that converts electrical energy into mechanical energy. An alternator is a device that converts mechanical energy into electrical energy. A breaker is a device that automatically interrupts an electrical circuit in case of overload or short circuit.

• Transformer transfers electrical energy thr...read more

I have a total of 18 years of experience in power plant and oil and gas plant.

• Experience includes working on various projects in power plant and oil and gas plant

• Knowledge of electrical systems, equipment, and regulations in these industries

• Hands-on experience in maintenance, troubleshooting, and project management

• Strong understanding of safety protocols and procedures in high-risk environments

Solar energy is converted to AC current using an inverter.

• DC power generated by solar panels is converted to AC power using an inverter.

• Inverter is an electronic device that changes DC to AC.

• AC power is used for household and industrial applications.

• Examples of inverters include string inverters, microinverters, and central inverters.

Transmission & distribution refers to the movement of electricity from power plants to consumers.

• Transmission involves high voltage power lines that transport electricity over long distances

• Distribution involves lower voltage lines that deliver electricity to homes and businesses

• Both are essential components of the electrical grid

• Examples of transmission equipment include transformers, circuit breakers, and substations

• Examples of distribution equipment include power poles, tr...read more

When phase and neutral are connected, it creates a short circuit which can lead to damage to the electrical system and potential fire hazards.

• Connecting phase and neutral directly can cause a short circuit

• This can lead to overheating of wires and potential fire hazards

• It can damage electrical appliances connected to the circuit

• Proper insulation and wiring practices should be followed to prevent such incidents

Power factor is the ratio of real power to apparent power in an AC circuit. Ohm's law states that the current flowing through a conductor is directly proportional to the voltage applied across it.

• 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 a purely resistive load, while a power factor less than 1 indicates a ...read more

Hydraulic and pneumatic systems are used to transmit power using fluids or gases.

• Hydraulic systems use liquids like oil to transmit power.

• Pneumatic systems use gases like air to transmit power.

• Both systems use pumps or compressors to generate pressure.

• Hydraulic systems are used in heavy machinery like cranes and excavators.

• Pneumatic systems are used in tools like jackhammers and nail guns.

My name means 'peaceful ruler' in Latin.

• My name is derived from the Latin word 'Pax' which means peace.

• It also has roots in the Roman goddess of peace, Pax.

• The name signifies a peaceful and authoritative presence.

A diode is a semiconductor device that allows current to flow in one direction only. Types include PN junction diode, Zener diode, Schottky diode, and LED.

• Diode is a semiconductor device with two terminals that allows current to flow in one direction only

• Types of diodes include PN junction diode, Zener diode, Schottky diode, and LED

• PN junction diode is the most common type, made of P-type and N-type semiconductor materials

• Zener diode is designed to operate in the reverse brea...read more

A resistor is an electrical component that resists the flow of electric current. There are various types of resistors based on their construction and materials used.

• Resistors are used to limit the flow of current in a circuit.

• Types of resistors include carbon film, metal film, wirewound, and variable resistors.

• Resistors are measured in ohms (Ω) and have color-coded bands to indicate their resistance value.

The number of panels in series and parallel depends on the system design and requirements.

• The number of panels in series is determined by the voltage requirements of the system.

• The number of panels in parallel is determined by the current requirements of the system.

• The total number of panels is a combination of series and parallel connections to meet the system specifications.

A diode is a semiconductor device that allows current to flow in one direction only.

• Diodes are made of semiconductor materials such as silicon or germanium.

• They have two terminals - an anode (positive) and a cathode (negative).

• When a voltage is applied across the diode in the forward direction, it allows current to flow.

• In the reverse direction, the diode blocks the current flow.

• Diodes are commonly used in rectifiers, voltage regulators, and signal demodulation.

• Examples of di...read more

Equipment erection involves following a specific procedure to ensure proper installation and testing procedures are carried out to verify functionality.

• Equipment erection procedure involves following manufacturer's guidelines and specifications.

• Testing procedures include conducting insulation resistance tests, continuity tests, and functional tests.

• Ensure all safety precautions are followed during equipment erection and testing procedures.

• Document all steps taken during equip...read more

Maintenance in bus bar system is necessary to ensure safety and reliability of electrical power distribution.

• Prevents overheating and potential fire hazards

• Identifies and repairs damaged or corroded components

• Ensures proper grounding and insulation

• Improves overall efficiency and reduces downtime

• Regular cleaning and inspection of bus bars

• Testing for continuity and resistance

• Tightening of connections and bolts

• Replacement of worn out or damaged parts

There are two types of insulators: Pin type and Suspension type.

• Pin type insulators are used for low voltage distribution lines.

• Suspension type insulators are used for high voltage transmission lines.

• Pin type insulators are mounted on the cross-arm of the pole.

• Suspension type insulators are suspended from the cross-arm of the tower.

• Pin type insulators have only one insulating unit.

• Suspension type insulators have multiple insulating units connected in series.

A feeder is an electrical circuit that supplies power to a branch circuit or a group of circuits.

• Feeder is used to distribute power to various loads in a building or facility.

• It is typically a larger gauge wire than the branch circuit it supplies.

• Feeder can be overhead or underground depending on the installation.

• Examples of feeders include the main electrical service entrance and subpanels.

• Feeder protection devices include circuit breakers and fuses.

Yes, DC cable laying refers to the process of installing and connecting direct current cables in electrical systems.

• DC cable laying involves selecting the appropriate cable size and type for the application

• The cables are then laid out and secured in place using cable trays, conduits, or other support systems

• The cables are then terminated and connected to the appropriate electrical components

• Proper insulation and grounding is crucial for safety and performance

• Examples of DC ca...read more

Electrical equipment and tools require proper understanding of their working principles and maintenance needs.

• Understanding the specifications and operating instructions of each equipment/tool is crucial

• Regular maintenance and calibration are necessary to ensure optimal performance

• Proper training on safe handling and operation of equipment/tools is essential

• Using appropriate personal protective equipment (PPE) when working with electrical tools is a must

• Being aware of potenti...read more

The voltage drop for a cable length of 40m depends on the cable size, current flow, and resistance.

• The cable size and current flow determine the resistance of the cable.

• The resistance of the cable determines the voltage drop.

• The voltage drop can be calculated using Ohm's Law: V = IR.

• For example, a 40m length of 2.5mm² cable carrying a current of 10A would have a voltage drop of approximately 1.6V.

Cabling process involves planning, routing, pulling, terminating and testing of cables.

• Plan the cable routing based on the requirements and specifications

• Pull the cables through the conduits or trays

• Terminate the cables at both ends using connectors or terminals

• Test the cables for continuity, insulation resistance and other parameters

• Label the cables for easy identification and maintenance

• Ensure compliance with safety regulations and standards

Managing manpower on site involves proper planning, communication, supervision, and coordination.

• Create a detailed schedule outlining tasks and responsibilities for each worker.

• Communicate effectively with the team to ensure everyone is aware of their roles and deadlines.

• Supervise the work progress regularly to identify any issues or delays.

• Coordinate with other teams or departments to avoid conflicts and ensure smooth workflow.

• Provide necessary training and support to improv...read more

Site engineer plays a crucial role in overseeing the construction site, ensuring quality, safety, and adherence to plans.

• Overseeing construction activities on site

• Ensuring compliance with project plans and specifications

• Quality control and assurance

• Managing subcontractors and workers

• Problem-solving and troubleshooting

• Ensuring safety regulations are followed

• Communicating with project managers and stakeholders

CT stands for Current Transformer, PT stands for Potential Transformer, and LA stands for Lightning Arrester.

• CT is used to measure and protect against high currents in electrical systems.

• PT is used to step down high voltage to a safe and measurable level.

• LA is used to protect electrical equipment from lightning strikes by diverting the lightning current to the ground.

• CT and PT are commonly used in power distribution systems, while LA is used in lightning protection systems.

Distribution boards are used to distribute electrical power to various circuits and equipment.

• Main distribution board (MDB) is used to distribute power to sub-distribution boards.

• Sub-distribution boards (SDB) are used to distribute power to final circuits.

• Final distribution boards (FDB) are used to distribute power to equipment.

• Motor control centers (MCC) are used to control and distribute power to motors.

• Lighting distribution boards (LDB) are used to distribute power to ligh...read more

HT cables are used for high voltage transmission while LT cables are used for low voltage transmission.

• HT cables have higher insulation and thicker conductor compared to LT cables.

• HT cables are used for transmission of electricity over long distances while LT cables are used for distribution of electricity within a building or a locality.

• HT cables are more expensive than LT cables.

• HT cables are usually installed underground while LT cables can be installed overhead or undergr...read more

RCCB and MCB are both electrical protection devices, but they differ in their functionality and applications.

• RCCB stands for Residual Current Circuit Breaker, while MCB stands for Miniature Circuit Breaker.

• RCCB is designed to protect against electrical leakage and ground faults, while MCB is primarily used for overcurrent protection.

• RCCB detects the imbalance in current between the live and neutral wires, while MCB detects excessive current flow.

• RCCB trips the circuit when it...read more

SPD stands for Surge Protection Device. It is used to protect electrical equipment from voltage spikes and surges.

• SPDs are installed in electrical systems to divert excess voltage away from sensitive equipment.

• They protect against lightning strikes, power surges, and other electrical disturbances.

• SPDs can be installed at various points in the electrical system, including at the service entrance, distribution panels, and individual equipment.

• Examples of equipment that may requ...read more