Question 1

Autotransformer

Accepted Answer

A transformer that has only one winding per phase, used to step up or step down voltage.

Question 2

Motor Control Center (MCC)

Accepted Answer

An assembly of motor starters or combination motor control units, arranged in a common enclosure.

Question 3

Variable Frequency Drive (VFD)

Accepted Answer

A power conversion device that varies the frequency of the electrical power supplied to an AC motor.

Question 4

Star-Delta Starter

Accepted Answer

A method for reducing the starting current of an induction motor by connecting the motor windings in a star configuration during startup, then switching to a delta configuration.

Question 5

Synchronous Motor

Accepted Answer

An AC motor that operates at a constant speed, determined by the frequency of the power supply and the number of poles in the motor.

Question 6

Overcurrent Protection

Accepted Answer

A device that detects excessive current flow and interrupts the circuit, protecting the equipment from damage.

Question 7

Thermocouple

Accepted Answer

A temperature-sensing device that generates a small voltage based on the difference in temperature between two dissimilar metals.

Question 8

Programmable Logic Controller (PLC)

Accepted Answer

A digital computer used for automation of electromechanical processes.

Question 9

Human-Machine Interface (HMI)

Accepted Answer

A device or software that allows an operator to interact with and control a machine or process.

Question 10

Conduit Fill

Accepted Answer

The amount of conductors or cables allowed in a conduit based on the cross-sectional area of the conduit.

Question 11

Ground Fault Circuit Interrupter (GFCI)

Accepted Answer

A device that detects and interrupts an electrical circuit when a leakage current to ground is detected.

Question 12

Short Circuit Current Rating (SCCR)

Accepted Answer

The maximum amount of fault current a device or component can safely withstand without damage.

Question 13

Power Factor

Accepted Answer

The ratio of real power to apparent power in an electrical circuit, indicating the efficiency of energy usage.

Question 14

Impedance

Accepted Answer

The opposition to alternating current flow in a circuit, measured in ohms.

Question 15

Feeder

Accepted Answer

A set of conductors that connect the main service equipment to a distribution panel or other equipment.

Question 16

Branch Circuit

Accepted Answer

A set of conductors that distribute electrical power from a distribution panel to individual loads.

Question 17

Electrical Hazardous Location

Accepted Answer

An area where the presence of flammable gases, vapors, dust, or fibers creates a risk of explosion or fire.

Question 18

Intrinsically Safe Circuit

Accepted Answer

A circuit designed to limit energy levels to prevent ignition in a hazardous location.

Question 19

Arc Flash Hazard

Accepted Answer

The risk of a high-energy arc due to a short circuit or other electrical fault, causing thermal and mechanical energy release.

Question 20

Lockout/Tagout

Accepted Answer

A safety procedure to ensure that machines and equipment are properly shut down and isolated from energy sources during maintenance.

Question 21

Time-Current Curve

Accepted Answer

A graphical representation of the relationship between the time it takes for a protective device to trip and the current flowing through it.

Question 22

Selective Coordination

Accepted Answer

The design of an electrical system to ensure that only the protective device nearest to a fault will trip, maintaining power to the rest of the system.

Question 23

Isolation Transformer

Accepted Answer

A transformer used to transfer electrical power from one circuit to another, while electrically isolating them from each other.

Question 24

Electrical Noise

Accepted Answer

Unwanted electrical signals or interference that can affect the performance of electrical equipment.

Question 25

Shielded Cable

Accepted Answer

A cable with a metallic layer surrounding the conductors to reduce electrical noise and interference.

Question 26

Harmonics

Accepted Answer

Distortion of the electrical waveform caused by nonlinear loads, such as variable frequency drives and rectifiers.

Question 27

Total Harmonic Distortion (THD)

Accepted Answer

A measure of the amount of harmonic distortion in an electrical waveform, expressed as a percentage of the fundamental frequency.

Question 28

Surge Protective Device (SPD)

Accepted Answer

A device that protects electrical equipment from voltage surges or spikes

Question 29

Uninterruptible Power Supply (UPS)

Accepted Answer

A device that provides backup power to critical loads during a power outage or voltage fluctuation.

Question 30

Busbar

Accepted Answer

A rigid conductor used for distributing high-current power in electrical panels or switchgear.

Question 31

Soft Starter

Accepted Answer

A device that gradually increases the voltage applied to a motor during startup, reducing the inrush current and mechanical stress.

Question 32

Slip Ring Rotor

Accepted Answer

A type of rotor used in wound-rotor induction motors, consisting of conducting bars connected to external resistors via slip rings.

Question 33

Wye-Connected Load

Accepted Answer

A load configuration where the load elements are connected in a star formation, with one end of each load connected to a common point.

Question 34

Delta-Connected Load

Accepted Answer

A load configuration where the load elements are connected in a triangular formation, with the ends of each load connected to adjacent loads.

Question 35

Insulation Resistance Test

Accepted Answer

A test performed to measure the resistance of a conductor's insulation, ensuring its integrity and effectiveness.

Question 36

Megger

Accepted Answer

A high-voltage insulation tester used to measure insulation resistance in electrical equipment.

Question 37

Continuity Test

Accepted Answer

A test performed to ensure that electrical connections are properly made and there are no breaks or shorts in a circuit.

Question 38

Ground Resistance Test

Accepted Answer

A test performed to measure the resistance of an earth grounding electrode to ensure effective fault current dissipation.

Question 39

Transformer Polarity

Accepted Answer

The phase relationship between the primary and secondary windings of a transformer, important for proper connection and operation.

Question 40

Transformer Turns Ratio

Accepted Answer

The ratio of the number of turns in the primary winding to the number of turns in the secondary winding, determining the voltage transformation ratio.

Question 41

Demand Factor

Accepted Answer

The ratio of the maximum power demand of a system to the total connected load, used to size electrical components and conductors.

Question 42

Diversity Factor

Accepted Answer

The ratio of the sum of individual maximum demands to the overall maximum demand in a system, accounting for the probability that not all loads will operate simultaneously.

Question 43

Load Balancing

Accepted Answer

The process of evenly distributing electrical loads across phases in a three-phase system to optimize power distribution and reduce losses.

Question 44

Torque

Accepted Answer

A rotational force applied to a shaft, measured in Newton-meters (Nm) or foot-pounds (ft-lb).

Question 45

Squirrel Cage Rotor

Accepted Answer

A type of rotor used in induction motors, consisting of shorted conductive bars embedded in a laminated iron core.

Question 46

Electrical Symbols

Accepted Answer

Standardized graphical representations used in electrical schematics and drawings to represent electrical components and connections.

Question 47

Single-Line Diagram

Accepted Answer

A simplified representation of an electrical system or component, using single lines and symbols to represent conductors and devices.

Question 48

Short Circuit Study

Accepted Answer

An analysis performed to determine the magnitude of fault currents in an electrical system, used to specify protective devices and equipment ratings.

Question 49

Load Flow Study

Accepted Answer

An analysis performed to determine the voltage, current, and power flow in an electrical system under normal operating conditions.

Question 50

Motor Nameplate Data

Accepted Answer

Information provided by the manufacturer on the motor nameplate, including voltage, current, speed, and other specifications.

Question 51

Permissible Voltage Drop

Accepted Answer

The maximum allowable voltage drop in a conductor, as specified by applicable standards or codes, to ensure proper equipment operation.

Question 52

Arc Blast

Accepted Answer

The release of mechanical energy and pressure waves caused by an arc fault, capable of causing injury or damage to equipment.

Question 53

Electrical Permit

Accepted Answer

A legal document required before beginning electrical work, ensuring that the work will be performed according to applicable codes and standards.

Question 54

Neutral Conductor

Accepted Answer

A conductor that carries unbalanced current in a multi-wire system, used to maintain a stable voltage reference.

Question 55

Grounding Electrode

Accepted Answer

A conductive element buried in the earth, used to establish a connection between an electrical system and the earth for safety and voltage stabilization purposes.

Question 56

Fault Current

Accepted Answer

The abnormal flow of current resulting from a short circuit or ground fault in an electrical system.

Question 57

Insulation Class

Accepted Answer

A classification system for electrical insulation materials, based on their maximum allowable operating temperature.

Question 58

Temperature Rise

Accepted Answer

The increase in temperature of electrical equipment during normal operation, due to heat generated by current flow and losses.

Red Seal Exam - Industrial Electrician Flash Cards