300+ Electrical Technician Interview Questions and Answers

FET (Field Effect Transistor) is a type of transistor that uses an electric field to control the flow of current.

• FETs are voltage-controlled devices, meaning they are controlled by the voltage applied to their terminals.

• There are two main types of FETs: MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) and JFET (Junction Field Effect Transistor).

• MOSFETs are widely used in various electronic devices, such as computers, smartphones, and power amplifiers.

• They have high ...read more

Current is the flow of electric charge in a circuit.

• Current is measured in amperes (A).

• It is the rate at which electric charge flows through a conductor.

• Current can be either direct current (DC) or alternating current (AC).

• In a DC circuit, the current flows in one direction only.

• In an AC circuit, the current changes direction periodically.

• Current is caused by the movement of electrons or other charged particles.

• It is essential for the operation of electrical devices and syste...read more

The interview questions cover motor starters, layout, power factor, troubleshooting with megger, and fault finding.

• Motor starters are used to control the starting and stopping of motors.

• There are different types of motor starters such as direct-on-line, star-delta, and soft starters.

• The power layout of starters includes power supply, motor, and control circuit.

• The control layout of starters includes start, stop, and overload protection.

• Power factor is the ratio of real power ...read more

Off load and on load OLTC and RTCC panels are used in electrical systems for voltage regulation and control.

• Off load OLTC panel is used to change the tap position of the transformer when it is not energized.

• On load OLTC panel is used to change the tap position of the transformer while it is energized.

• RTCC (Remote Tap Changing Control) panel is used to remotely control the tap changing operation of the transformer.

• Off load OLTC panel is typically used in situations where the t...read more

Yes, cable size estimation is based on the required load and can be calculated using various formulas.

• Cable size estimation is important to ensure safety and efficiency of electrical systems

• The required load can be calculated by adding up the wattage of all the devices that will be connected to the cable

• The cable size can then be estimated using formulas such as the voltage drop formula or the NEC ampacity tables

• Factors such as distance, temperature, and number of conductors ...read more

The statement refers to Kirchhoff's Current Law which states that the sum of currents entering a node is equal to the sum of currents leaving the node.

• Kirchhoff's Current Law is a fundamental law in electrical engineering

• It is also known as Kirchhoff's First Law or KCL

• The law applies to any node in an electrical circuit

• The algebraic sum of currents entering the node is equal to the algebraic sum of currents leaving the node

• The law is based on the principle of conservation of ...read more

I possess strong electrical skills, including troubleshooting, identifying short circuits, and understanding basic components.

• Proficient in using multimeters to measure voltage, current, and resistance, which helps in identifying short circuits.

• Experienced in reading and interpreting electrical schematics and diagrams to understand circuit layouts.

• Knowledgeable about basic electrical components such as resistors, capacitors, and inductors, and their functions in a circuit.

• Ski...read more

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

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 from star to delta configuration is controlled by a timer or...read more

A capacitor is an electronic component that stores and releases electrical energy. A transistor is a semiconductor device that amplifies or switches electronic signals. A variable frequency drive is an electronic device that controls the speed of an electric motor.

• A capacitor is used to store and release electrical energy.

• It consists of two conductive plates separated by an insulating material called a dielectric.

• When a voltage is applied across the plates, one plate accumula...read more

There are several types of motor protection relays used in electrical systems.

• Motor overload protection relays

• Motor thermal protection relays

• Motor phase loss protection relays

• Motor short circuit protection relays

• Motor underload protection relays

• Motor earth fault protection relays

• Motor stall protection relays

The question is about the concept of subtraction.

• The question is describing the process of subtraction.

• Taking 5 goods out of 13 means subtracting 5 from 13.

• The result of subtracting 5 from 13 is 8.

An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current.

• Alternators are commonly used in vehicles to charge the battery and power the electrical system

• Types of alternators include single-phase, three-phase, synchronous, and asynchronous

• Single-phase alternators are used in small appliances and power tools

• Three-phase alternators are used in industrial applications and power plants

• Synchronous alternators ar...read more

The company generates 500 MW of energy.

• The company's energy generation capacity is 500 MW.

• The company has a power plant that generates 500 MW of energy.

• The energy output of the company is 500 MW.

• The company's energy generation is sufficient to power a large city.

The number of starters used in our company varies depending on the specific projects and requirements.

• The number of starters used in our company is not fixed and can vary from project to project.

• We use starters for various electrical equipment such as motors, pumps, and compressors.

• The quantity of starters required depends on the size and complexity of the electrical systems.

• We follow industry standards and guidelines to determine the appropriate number of starters for each a...read more

A circuit breaker is an electrical switch that automatically interrupts the flow of current in a circuit.

• It is designed to protect electrical circuits from damage caused by excessive current or short circuits.

• When the current exceeds a certain limit, the circuit breaker trips and interrupts the flow of electricity.

• It can be manually reset after tripping or may automatically reset once the fault is cleared.

• Circuit breakers are commonly used in residential, commercial, and indu...read more

The first thing to do in case of a hazard is to ensure the safety of yourself and others.

• Assess the situation to determine the nature and extent of the hazard.

• Alert others in the vicinity about the hazard.

• Follow safety protocols and procedures to mitigate the hazard.

• Contact emergency services if necessary.

• Evacuate the area if instructed to do so.

Check for clogs in the fuel line, inspect the injector for damage, clean or replace the injector if necessary.

• Inspect the fuel line for any clogs or blockages

• Check the injector for any damage or malfunction

• Clean the injector using appropriate tools and techniques

• If cleaning doesn't work, consider replacing the injector

• Ensure proper fuel flow and pressure to the injector

To determine if a motor coil is damaged, check for continuity using a multimeter and inspect for physical damage.

• Use a multimeter to check for continuity in the coil windings

• Inspect the coil for any physical damage such as burns, breaks, or discoloration

• Compare the resistance readings with the manufacturer's specifications

• Check for any loose connections or faulty components in the motor circuit

• Consider testing other components such as the capacitor or start switch

Electricity is the flow of electrons while electronics deals with the control of the flow of electrons.

• Electricity is a natural phenomenon while electronics is a man-made technology.

• Electricity is the basic form of energy while electronics is a branch of science that deals with the study of electronic devices and their applications.

• Electricity is used to power electronic devices.

• Examples of electronic devices include computers, smartphones, televisions, and radios.

• Examples of...read more

The output voltage of a VFD varies based on frequency and load, typically ranging from 0 to the input voltage.

• VFD output voltage is adjustable, allowing control over motor speed and torque.

• The output voltage is proportional to the frequency; as frequency increases, voltage increases.

• Commonly, VFDs output a three-phase voltage to drive three-phase motors.

• For example, a 480V VFD can output up to 480V at its maximum frequency.

• VFDs can also provide a lower voltage output for soft...read more

The color code of resistance is a system used to identify the resistance value and tolerance of resistors.

• The color code consists of bands of different colors that represent specific values and tolerances.

• The first two bands indicate the significant digits of the resistance value.

• The third band represents the multiplier or the number of zeros to be added to the significant digits.

• The fourth band indicates the tolerance of the resistor.

• For example, a resistor with bands of bro...read more

An electrical technician is responsible for installing, maintaining, and repairing electrical systems and equipment.

• Installing electrical systems and equipment

• Maintaining electrical systems and equipment

• Repairing electrical systems and equipment

• Troubleshooting electrical issues

• Reading and interpreting technical diagrams and blueprints

• Ensuring compliance with safety regulations

• Testing electrical systems for functionality

• Collaborating with engineers and other technicians

The number of transformers depends on the specific context and location.

• The number of transformers can vary depending on the size and purpose of the electrical system.

• In a residential area, there may be one transformer serving multiple houses.

• In a commercial or industrial setting, there may be multiple transformers to meet the power demands.

• Transformers can also be found in power substations, where they step up or step down the voltage for transmission and distribution purpos...read more

Possible problems in starter and motor causing motor not to start.

• Check if there is power supply to the starter

• Inspect for any loose connections or damaged wires in the starter circuit

• Examine the starter motor for any mechanical issues such as worn out brushes or bearings

• Verify if the motor itself is faulty by checking for continuity and resistance in windings

Basic electrical wiring refers to the process of connecting electrical components in a circuit to allow electricity to flow and power devices.

• Basic electrical wiring involves connecting wires to electrical components such as switches, outlets, and light fixtures.

• The wiring must follow specific codes and standards to ensure safety and proper functioning.

• Common types of wiring include single-conductor, multi-conductor, and twisted pair.

• Proper insulation and grounding are essent...read more

A faulty battery can be identified by checking its voltage, capacity, and physical appearance.

• Check the voltage of the battery using a multimeter

• Test the capacity of the battery using a battery tester

• Inspect the physical appearance of the battery for any signs of damage or leakage

• Check the battery terminals for corrosion or loose connections

• Compare the battery's performance to its specifications