Industrial Electrical Terms and Definitions with Uses

Published on July 14, 2024 | Category: interview

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An industrial electrical system is the network of equipment, wiring, and control devices that deliver, distribute, and manage electrical energy inside a factory, plant, or other industrial facility. It includes power sources (like generators and the utility supply), transformers, switchgear, motors, protective devices (fuses and circuit breakers), distribution panels, and the control systems that make machines run reliably. The primary purpose of these systems is to convert utility power into the right voltages and controlled signals needed by production equipment while keeping people and assets safe.

Terminology in electrical engineering — words such as voltage, current, power factor, earthing, and relay — are more than technical labels: they are shorthand for precise physical behaviors and safety rules. Learning the correct meanings helps technicians read schematics, size cables and protective devices, troubleshoot faults, and communicate clearly with colleagues. For example, understanding the difference between single-phase and three-phase supplies determines how motors are selected and connected; knowing what “short-circuit current” means guides how protective devices are specified.

In practice, a clear grasp of terms speeds up maintenance, reduces downtime, and prevents accidents. Professionals rely on a common vocabulary to design safe systems, perform testing, and comply with standards. For anyone working in or learning about industrial electrical systems, a concise glossary paired with practical examples and diagrams makes the concepts easier to apply on the shop floor — from reading a wiring diagram to setting a motor overload correctly.

Industrial Electrical Terms – Questions & Answers

1. What is Voltage?

Voltage is the electrical potential difference between two points. It acts like pressure pushing current through a circuit. Use: Provides the energy needed to run machines.

2. What is Current?

Current is the flow of electric charge through a conductor, measured in amperes (A). Use: Represents the actual movement of electricity in a system.

3. What is Resistance?

Resistance is the opposition to current flow, measured in ohms (Ω). Use: Helps control current and protect devices.

4. What is Power in electricity?

Power is the rate of using or producing electrical energy, measured in watts (W). Use: Shows how much energy a machine consumes or generates.

5. What is Power Factor?

Power factor is the ratio of real power to apparent power. Use: Indicates efficiency of electrical systems and helps reduce industrial energy bills.

6. What is a Transformer?

A transformer is a device that changes AC voltage levels. Use: Steps voltage up for transmission or down for safe industrial use.

7. What is a Circuit Breaker?

A circuit breaker is a switch that automatically disconnects power during faults. Use: Protects circuits from overload and short circuits.

8. What is a Fuse?

A fuse is a protective device that melts when current is too high. Use: Prevents fire and damage to equipment.

9. What is a Relay?

A relay is an electrically operated switch. Use: Controls other circuits, used in automation and safety systems.

10. What is a Contactor?

A contactor is a heavy-duty relay for switching large currents. Use: Widely used in motor starters and control panels.

11. What is a Motor?

A motor is a machine that converts electrical energy into mechanical motion. Use: Runs pumps, fans, conveyors, and industrial machinery.

12. What is a Generator?

A generator converts mechanical energy into electricity. Use: Provides backup or main power supply in industries.

13. What is an Alternator?

An alternator produces AC electricity using electromagnetic induction. Use: Common in power plants and vehicles.

14. What is a Capacitor?

A capacitor stores and releases electrical energy. Use: Improves power factor and stabilizes voltage in industries.

15. What is an Inductor?

An inductor stores energy in a magnetic field. Use: Used in filters, chokes, and power circuits.

16. What is a PLC (Programmable Logic Controller)?

A PLC is a digital device for industrial automation. Use: Controls machines and processes based on programmed logic.

17. What is a VFD (Variable Frequency Drive)?

A VFD controls motor speed by changing supply frequency. Use: Saves energy and improves process control.

18. What is Switchgear?

Switchgear is a combination of switches, fuses, and breakers. Use: Protects and controls industrial electrical systems.

19. What is a Distribution Panel?

A distribution panel distributes power into smaller circuits. Use: Supplies safe power across different factory sections.

20. What is Earthing (Grounding)?

Earthing connects electrical parts to the earth for safety. Use: Protects people and equipment from electric shock.

21. What is an Overload?

Overload happens when current exceeds safe limits. Use: Protection devices trip to avoid overheating and fire.

22. What is a Short Circuit?

A short circuit is a direct low-resistance path for current. Use: Causes high current and requires breakers/fuses for safety.

23. What is a CT (Current Transformer)?

A CT steps down high current to a smaller measurable value. Use: Used with meters and protection relays.

24. What is a PT (Potential Transformer)?

A PT steps down high voltage to a safe measurable level. Use: Used in power system metering.

25. What is an MCC (Motor Control Center)?

An MCC is a cabinet that houses motor starters and control gear. Use: Centralized motor control in industries.

26. What is SCADA?

SCADA stands for Supervisory Control and Data Acquisition. Use: Monitors and controls industrial processes remotely.

27. What is a UPS (Uninterruptible Power Supply)?

A UPS provides emergency power during outages. Use: Protects sensitive equipment from downtime and data loss.

28. What is an Inverter?

An inverter converts DC power into AC power. Use: Used in solar systems, UPS, and backup supplies.

29. What is a Rectifier?

A rectifier converts AC power into DC power. Use: Powers DC machines and chargers.

30. What are Harmonics in power systems?

Harmonics are unwanted frequency distortions in electrical supply. Use: Must be reduced to improve efficiency and avoid overheating.

31. What is a Busbar?

A busbar is a metal bar that carries current inside switchgear or panels. Use: Distributes high current safely to multiple circuits.

32. What is an Insulator?

An insulator is a material that does not conduct electricity. Use: Protects people and equipment from unwanted current flow.

33. What is a Conductor?

A conductor is a material that allows electricity to flow easily. Use: Wires and cables are conductors in all power systems.

34. What is a Cable Tray?

A cable tray is a mechanical support system for cables. Use: Provides safe routing of wires in industries.

35. What is an Electrical Load?

An electrical load is any device that consumes electricity. Use: Lights, motors, and machines are common loads in industries.

36. What is an Overcurrent Relay?

An overcurrent relay is a protection device that operates when current exceeds a preset limit. Use: Protects circuits and equipment from excessive current flow.

37. What is an Earth Leakage Circuit Breaker (ELCB)?

An ELCB is a safety device that disconnects power when leakage current flows to the earth. Use: Prevents electric shocks and fire hazards.

38. What is an RCCB (Residual Current Circuit Breaker)?

An RCCB is a modern version of ELCB that trips when imbalance occurs between live and neutral. Use: Protects humans from electric shock.

39. What is a Surge Protector?

A surge protector safeguards equipment from voltage spikes. Use: Protects sensitive electronics from lightning and switching surges.

40. What is a Lightning Arrester?

A lightning arrester protects equipment from lightning strikes by diverting surge currents to earth. Use: Installed on substations and tall industrial buildings.

41. What is a Stepper Motor?

A stepper motor is a motor that moves in discrete steps. Use: Used in robotics, CNC machines, and automation.

42. What is a Servo Motor?

A servo motor is a motor with precise control of position, speed, and torque. Use: Common in robotics, packaging, and automation systems.

43. What is a Soft Starter?

A soft starter reduces the voltage during motor startup to avoid high inrush current. Use: Extends motor life and reduces mechanical stress.

44. What is a Thyristor?

A thyristor is a semiconductor device used for switching and controlling power. Use: Found in VFDs, UPS, and industrial rectifiers.

45. What is a Diode?

A diode allows current to flow in one direction only. Use: Used in rectifiers, power supplies, and protection circuits.

46. What is a Transistor?

A transistor is a semiconductor device used for amplification and switching. Use: Found in control circuits and electronic drives.

47. What is an Alternating Current (AC)?

AC is an electric current that changes direction periodically. Use: Supplied by power companies for industrial and domestic use.

48. What is Direct Current (DC)?

DC is an electric current that flows in one direction. Use: Used in batteries, electronics, and electroplating.

49. What is a Neutral Wire?

A neutral wire carries current back to the source in AC systems. Use: Completes the circuit and provides return path for electricity.

50. What is a Phase Wire?

A phase wire carries live current from the supply to loads. Use: Delivers power to motors, lights, and machines.

51. What is a Three-Phase System?

A three-phase system uses three alternating currents, each 120° apart. Use: Provides efficient power for motors and heavy equipment.

52. What is a Single-Phase System?

A single-phase system uses one alternating current. Use: Common in homes and small equipment.

53. What is a Load Break Switch?

A load break switch is used to safely open and close circuits under load conditions. Use: Provides isolation in distribution networks.

54. What is an Isolator?

An isolator is a mechanical switch used to disconnect a circuit when no load is flowing. Use: Ensures safety during maintenance.

55. What is a Ballast?

A ballast controls the current in fluorescent lamps. Use: Ensures stable lighting and protects the lamp.

56. What is an Electrical Panel?

An electrical panel is a box containing breakers, fuses, and switches. Use: Distributes power across circuits in industries.

57. What is a Frequency?

Frequency is the number of cycles of AC per second, measured in Hertz (Hz). Use: In India it is 50 Hz, in the US it is 60 Hz.

58. What is a Load Shedding?

Load shedding is the deliberate shutdown of power supply to balance demand and supply. Use: Prevents system overload and blackouts.

59. What is a Kilowatt-hour (kWh)?

A kilowatt-hour is the unit of electrical energy used for billing. Use: Shows how much electricity a factory or household consumes.

60. What is a Smart Meter?

A smart meter is an electronic device that records energy consumption in real time. Use: Helps industries monitor usage and reduce costs.

61. What is an Ammeter?

An ammeter is an instrument used to measure electric current in amperes. Use: Installed in panels to monitor load current.

62. What is a Voltmeter?

A voltmeter measures the voltage between two points in a circuit. Use: Helps check supply levels and troubleshoot faults.

63. What is a Wattmeter?

A wattmeter measures real power in a circuit. Use: Used in industries to monitor machine power consumption.

64. What is an Energy Meter?

An energy meter measures the total energy consumed in kilowatt-hours (kWh). Use: Used by electricity boards for billing and monitoring.

65. What is Synchronization in electrical systems?

Synchronization is the process of matching voltage, frequency, and phase of two power sources. Use: Required before connecting a generator to a power grid.

66. What is a Power Grid?

A power grid is the interconnected network of power generation, transmission, and distribution systems. Use: Delivers electricity from plants to consumers.

67. What is Transmission Line?

A transmission line carries high-voltage power from generating stations to substations. Use: Enables long-distance power transfer.

68. What is a Distribution Line?

A distribution line carries medium- or low-voltage electricity from substations to consumers. Use: Supplies electricity to industries and households.

69. What is a Load Center?

A load center is a small distribution panel for local circuits. Use: Common in buildings and small factories.

70. What is an Arc in electricity?

An arc is a visible plasma discharge between two conductors. Use: Dangerous but used intentionally in welding applications.

71. What is Arc Flash?

Arc flash is a sudden release of electrical energy through the air caused by a fault. Use: Requires PPE and safety measures to protect workers.

72. What is Arc Suppression?

Arc suppression is the method of reducing or eliminating arcs when opening a circuit. Use: Protects contacts in relays and switches.

73. What is Dielectric Strength?

Dielectric strength is the maximum voltage a material can withstand without breaking down. Use: Important for insulation design.

74. What is a Transformer Tap Changer?

A tap changer adjusts the output voltage of a transformer. Use: Maintains stable supply voltage in industries.

75. What is Load Balancing?

Load balancing is the even distribution of electrical load across phases. Use: Prevents overheating and improves efficiency.

76. What is Demand Factor?

Demand factor is the ratio of maximum demand to total connected load. Use: Helps design electrical systems economically.

77. What is Diversity Factor?

Diversity factor is the ratio of sum of individual maximum demands to the maximum demand of the system. Use: Reduces system capacity requirements.

78. What is Load Factor?

Load factor is the ratio of average load to maximum load in a period. Use: Indicates efficiency of energy use in industries.

79. What is Fault Current?

Fault current is the excessive current that flows during a short circuit. Use: Determines breaker and fuse ratings.

80. What is Insulation Resistance?

Insulation resistance is the resistance offered by insulating material to current leakage. Use: Tested using a megger to ensure safety of equipment.

81. What is a Busbar?

A busbar is a metallic strip or bar that conducts electricity within switchgear, panels, or substations. Use: Distributes power to multiple outgoing circuits.

82. What is a Bus Coupler?

A bus coupler is a circuit breaker that connects two busbars. Use: Provides flexibility in power distribution and maintenance.

83. What is a Ring Main Unit (RMU)?

An RMU is a type of medium-voltage switchgear used for distribution. Use: Ensures continuous supply even during faults.

84. What is an Isolator?

An isolator is a switch used to completely disconnect a circuit when no current is flowing. Use: Provides safety during maintenance.

85. What is a Circuit Breaker?

A circuit breaker is a protective device that automatically interrupts current during faults. Use: Prevents fire, shock, and equipment damage.

86. What is an MCCB?

Molded Case Circuit Breaker (MCCB) is used for medium current ratings. Use: Protects circuits in industries from overload and short circuits.

87. What is an ACB?

Air Circuit Breaker (ACB) is a breaker that operates in air as an arc extinguishing medium. Use: Used in low-voltage power distribution panels.

88. What is an OCB?

Oil Circuit Breaker (OCB) uses oil for arc extinction. Use: Common in high-voltage substations, though now replaced by modern types.

89. What is an SF6 Circuit Breaker?

An SF6 breaker uses sulfur hexafluoride gas for arc extinguishing. Use: Reliable for high-voltage applications.

90. What is a Relay?

A relay is an electrically operated switch that controls circuits using a small signal. Use: Provides protection, automation, and control.

91. What is a Protection Relay?

A protection relay detects abnormal conditions like overload or fault. Use: Trips circuit breakers to isolate faulty equipment.

92. What is a Thermal Overload Relay?

A thermal overload relay protects motors from overheating. Use: Trips the motor when excessive current flows for too long.

93. What is an Earth Leakage Circuit Breaker (ELCB)?

An ELCB trips when leakage current flows to earth. Use: Protects people from electric shock hazards.

94. What is a Residual Current Circuit Breaker (RCCB)?

An RCCB disconnects power when it detects current imbalance between phase and neutral. Use: Provides personal safety from shock.

95. What is an RCBO?

An RCBO combines MCB and RCCB functions. Use: Protects against both overload/short circuit and earth leakage.

96. What is a VFD?

A Variable Frequency Drive (VFD) controls motor speed by varying frequency and voltage. Use: Saves energy and improves motor efficiency.

97. What is a Soft Starter?

A soft starter reduces motor starting current using voltage control. Use: Prevents mechanical and electrical stress during motor startup.

98. What is a PLC?

A Programmable Logic Controller (PLC) is an industrial computer for automation. Use: Controls machines, processes, and safety systems.

99. What is SCADA?

Supervisory Control and Data Acquisition (SCADA) is a system for remote monitoring and control. Use: Used in factories, power plants, and utilities.

100. What is DCS?

A Distributed Control System (DCS) is a control system with multiple controllers distributed across a plant. Use: Provides reliable process control in industries like oil, gas, and power.

101. What is an Alternator?

An alternator is a machine that generates AC electricity from mechanical energy. Use: Widely used in power plants and backup generators.

102. What is a Generator?

A generator converts mechanical energy into electrical energy (AC or DC). Use: Supplies power during outages and in remote sites.

103. What is a Motor?

A motor converts electrical energy into mechanical energy. Use: Powers machines, pumps, fans, and conveyors in industries.

104. What is a Synchronous Motor?

A synchronous motor runs at constant speed equal to supply frequency. Use: Used where precise constant speed is required.

105. What is an Induction Motor?

An induction motor is the most common AC motor where current is induced in the rotor. Use: Drives industrial machinery and fans.

106. What is a Single-phase Motor?

A single-phase motor operates on single-phase supply. Use: Used in household appliances and small machines.

107. What is a Three-phase Motor?

A three-phase motor runs on three-phase power supply. Use: Powers heavy industrial equipment with high efficiency.

108. What is a Slip Ring Motor?

A slip ring motor is a type of induction motor with external resistances connected to the rotor. Use: Provides high starting torque for cranes and elevators.

109. What is a Stepper Motor?

A stepper motor rotates in discrete steps. Use: Used in robotics, CNC machines, and automation systems.

110. What is a Servo Motor?

A servo motor provides precise position control. Use: Used in robotics, process control, and instrumentation.

111. What is Power Factor?

Power factor is the ratio of real power to apparent power. Use: Indicates efficiency of electrical systems.

112. What is Power Factor Correction?

Power factor correction improves low power factor by adding capacitors or synchronous condensers. Use: Reduces losses and electricity bills.

113. What is a Capacitor Bank?

A capacitor bank is a group of capacitors connected together. Use: Used for power factor correction in industries.

114. What is a Harmonic in electricity?

Harmonics are voltage or current distortions at multiples of the fundamental frequency. Use: Must be controlled to avoid overheating and malfunction.

115. What is a Harmonic Filter?

A harmonic filter reduces unwanted harmonics from the system. Use: Protects equipment and improves power quality.

116. What is Earthing?

Earthing is the connection of electrical equipment to the ground. Use: Provides safety from shocks and stabilizes system voltage.

117. What is Neutral?

Neutral is the return path of current in an electrical system. Use: Completes the circuit and ensures balanced operation.

118. What is a Lightning Arrester?

A lightning arrester protects equipment from high-voltage surges due to lightning. Use: Installed in substations and transmission lines.

119. What is a Surge Protector?

A surge protector protects electrical devices from voltage spikes. Use: Commonly used in homes, offices, and industries.

120. What is a UPS?

An Uninterruptible Power Supply (UPS) provides backup power instantly during supply failure. Use: Protects computers, servers, and sensitive equipment.

121. What is an Inverter?

An inverter converts DC power into AC power. Use: Used in solar systems, UPS, and variable speed drives.

122. What is a Rectifier?

A rectifier converts AC power into DC power. Use: Used in battery charging, DC drives, and electronic devices.

123. What is a Battery?

A battery stores electrical energy in chemical form. Use: Provides backup power and runs portable devices.

124. What is a Battery Bank?

A battery bank is a group of batteries connected together for higher voltage or capacity. Use: Common in UPS, solar, and telecom systems.

125. What is a Substation?

A substation is a part of the power system where voltage is transformed and distributed. Use: Ensures reliable electricity supply to industries and cities.

126. What is a Switchyard?

A switchyard is an open-air arrangement of electrical equipment at high voltage. Use: Connects power stations and transmission lines.

127. What is a GIS Substation?

Gas Insulated Substation (GIS) uses SF6 gas for insulation. Use: Saves space and is used in urban or high-density areas.

128. What is an AIS Substation?

Air Insulated Substation (AIS) uses air as insulating medium. Use: Common and cost-effective for large open areas.

129. What is a Transformer Substation?

A transformer substation steps up or steps down voltage for transmission or distribution. Use: Links generation with distribution networks.

130. What is Load Shedding?

Load shedding is the intentional shutdown of power in some areas to balance demand and supply. Use: Prevents grid collapse during peak demand.

131. What is Blackout?

A blackout is a complete loss of power in a large area. Use: Can occur due to faults, storms, or grid failures.

132. What is Brownout?

A brownout is a partial voltage drop in the supply. Use: Causes lights to dim and motors to underperform.

133. What is an Overvoltage?

Overvoltage is when the supply voltage exceeds its normal value. Use: Dangerous for sensitive equipment, requires surge protection.

134. What is Undervoltage?

Undervoltage is when the supply voltage drops below normal. Use: Causes motors to overheat and malfunction.

135. What is Frequency in electricity?

Frequency is the number of cycles per second of AC power, measured in Hertz (Hz). Use: Standard is 50Hz in many countries and 60Hz in others.

136. What is a Frequency Converter?

A frequency converter changes the frequency of electrical supply. Use: Used for testing equipment and running imported machinery.

137. What is Reactive Power?

Reactive power is the power that oscillates between source and load but does not perform useful work. Use: Needed for magnetizing motors and transformers.

138. What is Apparent Power?

Apparent power is the product of voltage and current, measured in kVA. Use: Determines transformer and generator ratings.

139. What is Real Power?

Real power is the actual usable power in a circuit, measured in kW. Use: Runs machines, lights, and equipment.

140. What is a Power Quality?

Power quality refers to maintaining voltage, frequency, and waveform within safe limits. Use: Ensures smooth operation of sensitive equipment.

141. What is HVDC?

High Voltage Direct Current (HVDC) is a method of transmitting electricity over long distances using DC. Use: Reduces transmission losses across continents and underwater cables.

142. What is HVAC in power systems?

High Voltage Alternating Current (HVAC) is the standard method of power transmission. Use: Easier to transform voltage levels for distribution.

143. What is a Smart Grid?

A smart grid is an advanced electrical grid that uses digital communication and automation. Use: Improves efficiency, reliability, and renewable energy integration.

144. What is Microgrid?

A microgrid is a small-scale power system that can operate independently or with the main grid. Use: Provides local energy security in industries and communities.

145. What is Demand Response?

Demand response is adjusting electricity consumption during peak times. Use: Helps balance grid load and avoid blackouts.

146. What is Load Forecasting?

Load forecasting is predicting future electricity demand. Use: Guides planning and operation of power systems.

147. What is SC Current?

SC current means Short-Circuit current, the sudden surge of current due to a fault. Use: Used for sizing breakers and protection systems.

148. What is Relay Coordination?

Relay coordination is the process of setting relays to trip in correct order. Use: Ensures selective fault isolation.

149. What is a Ground Fault?

A ground fault occurs when current flows directly to earth. Use: Requires ground fault protection to avoid hazards.

150. What is a Line Fault?

A line fault is an abnormal condition in transmission lines like L-G, L-L, or 3-phase faults. Use: Affects grid stability, needs protection relays.

151. What is Earthing Resistance?

Earthing resistance is the resistance between an earth electrode and ground. Use: Should be kept low for safety.

152. What is Step Potential?

Step potential is the voltage difference between two feet on the ground during a fault. Use: Dangerous in substations, requires proper earthing design.

153. What is Touch Potential?

Touch potential is the voltage difference between equipment and ground. Use: Can cause shock, mitigated by earthing.

154. What is Double Earthing?

Double earthing means connecting two separate earth conductors. Use: Improves safety for heavy machines.

155. What is Plate Earthing?

Plate earthing uses copper or GI plates buried in soil. Use: Common in industrial and domestic installations.

156. What is Pipe Earthing?

Pipe earthing uses a hollow GI pipe buried in the ground. Use: Economical method for small loads.

157. What is Strip Earthing?

Strip earthing uses metal strips or conductors buried in trenches. Use: Suitable for substations and large plants.

158. What is Lightning Protection System?

A system that protects buildings from lightning strikes using conductors and arresters. Use: Provides safe discharge path to earth.

159. What is Overcurrent Protection?

Protection that trips when current exceeds safe value. Use: Prevents damage from overloads or short circuits.

160. What is Differential Protection?

Differential protection compares current entering and leaving equipment. Use: Common in transformer and motor protection.

161. What is Distance Protection?

Distance protection detects line faults by measuring impedance. Use: Used in transmission lines.

162. What is Underfrequency Protection?

Protection that trips load or generator if system frequency drops too low. Use: Prevents grid collapse.

163. What is Overfrequency Protection?

Protection that trips generators if frequency rises abnormally. Use: Protects turbines and grid.

164. What is HV Switchgear?

High-voltage switchgear controls and protects HV circuits. Use: Used in substations above 33kV.

165. What is LV Switchgear?

Low-voltage switchgear operates below 1kV. Use: Found in factories and commercial buildings.

166. What is MV Switchgear?

Medium-voltage switchgear works between 1kV and 33kV. Use: Common in distribution networks.

167. What is a Feeder?

A feeder is a power line carrying electricity from a substation to distribution points. Use: Supplies multiple consumers.

168. What is a Service Line?

A service line is the connection from distribution point to end user. Use: Provides power to homes and small industries.

169. What is an Auto Transformer?

An auto transformer has a single winding with taps. Use: Used for voltage regulation and motor starting.

170. What is a Step-up Transformer?

A transformer that increases voltage. Use: Used in power plants for transmission.

171. What is a Step-down Transformer?

A transformer that reduces voltage. Use: Used for distribution to industries and homes.

172. What is a Potential Transformer (PT)?

A PT reduces high voltage to measurable level. Use: Used for metering and protection.

173. What is a Current Transformer (CT)?

A CT reduces high current to a small value. Use: Used in meters and relays.

174. What is a Smart Meter?

A smart meter digitally measures and reports energy usage. Use: Helps consumers and utilities manage energy efficiently.

175. What is Net Metering?

Net metering allows solar users to export surplus power to the grid. Use: Reduces electricity bills.

176. What is Grid Stability?

Grid stability means maintaining steady frequency and voltage. Use: Essential for reliable power supply.

177. What is a Black Start?

Black start is restoring power without external supply. Use: Power plants use it after total grid collapse.

178. What is an Exciter?

An exciter supplies DC to generator field windings. Use: Controls generator voltage.

179. What is AVR?

Automatic Voltage Regulator (AVR) controls generator output voltage. Use: Maintains stable power supply.

180. What is a Turbine?

A turbine converts steam, gas, or water energy into mechanical energy. Use: Drives generators in power plants.

181. What is a Solar Inverter?

A solar inverter converts DC from panels into AC. Use: Supplies usable power from solar systems.

182. What is a Wind Turbine?

A wind turbine converts wind energy into electricity. Use: Provides renewable energy to the grid.

183. What is Biomass Power?

Biomass power uses organic waste as fuel for electricity generation. Use: Provides sustainable energy.

184. What is Geothermal Energy?

Geothermal energy comes from heat inside the earth. Use: Generates power in geothermal plants.

185. What is Tidal Power?

Tidal power uses ocean tides to produce electricity. Use: Renewable energy from sea movements.

186. What is HV Test?

High-voltage test checks insulation strength of equipment. Use: Ensures safety before commissioning.

187. What is a Megger?

A megger is an insulation resistance tester. Use: Checks health of cables and motors.

188. What is a Clamp Meter?

A clamp meter measures current without breaking the circuit. Use: Quick and safe current measurement.

189. What is a Multimeter?

A multimeter measures voltage, current, and resistance. Use: Essential tool for electricians and engineers.

190. What is Infrared Thermography?

Infrared thermography detects hot spots in electrical systems. Use: Prevents failures by early fault detection.

191. What is Partial Discharge?

Partial discharge is a localized breakdown of insulation. Use: Indicates deterioration in HV equipment.

192. What is Corona Effect?

Corona effect is ionization of air around conductors at high voltage. Use: Causes losses, needs prevention in transmission lines.

193. What is Ferranti Effect?

Ferranti effect is voltage rise at receiving end of long transmission lines under light load. Use: Considered in HV line design.

194. What is Skin Effect?

Skin effect is current concentrating on the outer surface of conductors at high frequency. Use: Increases effective resistance of conductors.

195. What is Proximity Effect?

Proximity effect is when current distribution in a conductor changes due to nearby conductors. Use: Affects cable performance in AC systems.

196. What is Eddy Current?

Eddy current is circulating current induced in conductors by changing magnetic fields. Use: Causes losses, but used in induction heating.

197. What is Hysteresis Loss?

Hysteresis loss is energy loss in magnetic material due to repeated magnetization. Use: Major loss in transformers.

198. What is Dielectric Loss?

Dielectric loss is energy loss in insulating materials under alternating fields. Use: Considered in capacitor design.

199. What is Stray Loss?

Stray loss is power loss due to leakage flux and harmonics. Use: Reduces machine efficiency.

200. What is Efficiency in electrical machines?

Efficiency is the ratio of output power to input power. Use: Higher efficiency reduces energy cost in industries.

201. What is the full form of PCC?

PCC stands for Power Control Center. Use: It is a panel that controls and distributes electrical power to different loads in industries.

202. What is the full form of MCC?

MCC stands for Motor Control Center. Use: It houses motor starters, overload protection, and feeders for motor operations.

203. What is the full form of APFC?

APFC stands for Automatic Power Factor Control. Use: It is a panel that improves power factor by automatically switching capacitor banks.

204. What is the full form of ACB?

ACB stands for Air Circuit Breaker. Use: It protects electrical circuits from faults by using air as an arc quenching medium.

205. What is the full form of VCB?

VCB stands for Vacuum Circuit Breaker. Use: It interrupts current using vacuum and is common in medium-voltage systems.

206. What is the full form of SF6 CB?

SF6 CB stands for Sulphur Hexafluoride Circuit Breaker. Use: It uses SF6 gas as an arc extinguishing medium, suitable for high voltage.

207. What is the full form of RCCB?

RCCB stands for Residual Current Circuit Breaker. Use: It protects people from electric shock due to leakage currents.

208. What is the full form of MCB?

MCB stands for Miniature Circuit Breaker. Use: Protects small circuits from overload and short circuits.

209. What is the full form of MCCB?

MCCB stands for Molded Case Circuit Breaker. Use: Used for higher current ratings than MCB, provides thermal and short-circuit protection.

210. What is the full form of ELCB?

ELCB stands for Earth Leakage Circuit Breaker. Use: Protects from earth leakage faults and prevents shock.

211. What is the full form of LCS?

LCS stands for Local Control Station. Use: A small panel used for operating motors locally.

212. What is the full form of HT Panel?

HT Panel stands for High Tension Panel. Use: Controls and distributes power at high voltage levels (above 11kV).

213. What is the full form of LT Panel?

LT Panel stands for Low Tension Panel. Use: Distributes electricity at low voltage (up to 1000V).

214. What is the full form of UPS?

UPS stands for Uninterruptible Power Supply. Use: Provides backup power during outages to critical loads like computers and control systems.

215. What is the full form of DG?

DG stands for Diesel Generator. Use: Provides standby electrical power during utility failures.

216. What is the full form of SCADA?

SCADA stands for Supervisory Control and Data Acquisition. Use: It monitors and controls industrial electrical systems remotely.

217. What is the full form of PLC?

PLC stands for Programmable Logic Controller. Use: An industrial computer used for automation and control of machinery.

218. What is the full form of DOL Starter?

DOL Starter stands for Direct On-Line Starter. Use: A simple motor starter that connects the motor directly to supply.

219. What is the full form of VFD?

VFD stands for Variable Frequency Drive. Use: Controls motor speed and saves energy in pumps, fans, and conveyors.

220. What is the full form of AVR?

AVR stands for Automatic Voltage Regulator. Use: Maintains stable generator output voltage.

221. What is the full form of CT?

CT stands for Current Transformer. Use: It reduces high current to a measurable level for meters and protection devices.

222. What is the full form of PT?

PT stands for Potential Transformer. Use: It reduces high voltage to a lower, safe level for measurement and protection.

223. What is the full form of OCB?

OCB stands for Oil Circuit Breaker. Use: Uses insulating oil as an arc quenching medium in high-voltage systems.

224. What is the full form of HRC Fuse?

HRC Fuse stands for High Rupturing Capacity Fuse. Use: Protects circuits by breaking high fault currents safely.

225. What is the full form of SPD?

SPD stands for Surge Protection Device. Use: Protects equipment from voltage spikes caused by lightning or switching.

226. What is the full form of GIS?

GIS stands for Gas Insulated Switchgear. Use: Compact switchgear using SF6 gas, suitable for space-limited areas.

227. What is the full form of AIS?

AIS stands for Air Insulated Switchgear. Use: Conventional switchgear using air as insulation, widely used in open substations.

228. What is the full form of IP Rating?

IP stands for Ingress Protection. Use: Indicates protection level against dust and water, e.g., IP55, IP67.

229. What is the full form of THD?

THD stands for Total Harmonic Distortion. Use: Represents distortion in electrical waveforms, affects power quality.

230. What is the full form of DG Set?

DG Set stands for Diesel Generator Set. Use: Provides backup power during utility failures.

231. What is the full form of PCC Panel?

PCC Panel stands for Power Control Center Panel. Use: Distributes and manages electrical load in industries.

232. What is the full form of ATS?

ATS stands for Automatic Transfer Switch. Use: Switches load between utility and generator automatically during power failure.

233. What is the full form of AMF?

AMF stands for Automatic Mains Failure. Use: Automatically starts a generator when mains supply fails.

234. What is the full form of RMS?

RMS stands for Root Mean Square. Use: It is the effective value of AC voltage or current.

235. What is the full form of KVAR?

KVAR stands for Kilo Volt Ampere Reactive. Use: Unit of reactive power in AC circuits.

236. What is the full form of kVA?

kVA stands for Kilo Volt Ampere. Use: Unit of apparent power, used in transformer and generator ratings.

237. What is the full form of kW?

kW stands for Kilowatt. Use: Unit of real power, represents actual usable power.

238. What is the full form of LV?

LV stands for Low Voltage. Use: Electrical systems operating below 1 kV.

239. What is the full form of MV?

MV stands for Medium Voltage. Use: Electrical systems operating between 1 kV and 33 kV.

240. What is the full form of HV?

HV stands for High Voltage. Use: Electrical systems operating above 33 kV.

241. What is the full form of EHV?

EHV stands for Extra High Voltage. Use: Electrical transmission systems operating above 220 kV.

242. What is the full form of UHV?

UHV stands for Ultra High Voltage. Use: Transmission systems operating above 800 kV for long-distance bulk power transfer.

243. What is the full form of HVDC?

HVDC stands for High Voltage Direct Current. Use: Used for long-distance transmission with lower losses compared to AC.

244. What is the full form of OLTC?

OLTC stands for On Load Tap Changer. Use: Adjusts transformer voltage under load without interrupting supply.

245. What is the full form of AVR?

AVR stands for Automatic Voltage Regulator. Use: Maintains constant generator or alternator output voltage.

246. What is the full form of DCS?

DCS stands for Distributed Control System. Use: Industrial automation system for controlling complex processes.

247. What is the full form of HMI?

HMI stands for Human Machine Interface. Use: Screen or software interface that allows operators to control machines.

248. What is the full form of BMS?

BMS stands for Battery Management System. Use: Monitors and controls battery charging, discharging, and safety.

249. What is the full form of EMS?

EMS stands for Energy Management System. Use: Monitors and optimizes energy consumption in industries.

250. What is the full form of PMS?

PMS stands for Power Management System. Use: Controls power distribution and load sharing in plants.

251. What is the full form of RTU?

RTU stands for Remote Terminal Unit. Use: Collects data and communicates with SCADA in substations.

252. What is the full form of IED?

IED stands for Intelligent Electronic Device. Use: Smart device for protection, control, and monitoring in substations.

253. What is the full form of FACTS?

FACTS stands for Flexible AC Transmission Systems. Use: Enhances power transfer capability and stability of transmission networks.

254. What is the full form of STATCOM?

STATCOM stands for Static Synchronous Compensator. Use: Provides reactive power support for voltage regulation.

255. What is the full form of SVC?

SVC stands for Static VAR Compensator. Use: Improves voltage stability by controlling reactive power.

256. What is the full form of LVRT?

LVRT stands for Low Voltage Ride Through. Use: Ability of wind/solar plants to stay connected during grid voltage dips.

257. What is the full form of HVRT?

HVRT stands for High Voltage Ride Through. Use: Ability of power plants to withstand temporary overvoltage conditions.

258. What is the full form of PCC in power quality?

PCC stands for Point of Common Coupling. Use: The point where multiple users or loads connect to a common supply system.

259. What is the full form of IPB?

IPB stands for Isolated Phase Bus. Use: Bus duct system where each phase conductor is enclosed separately to reduce faults.

260. What is the full form of NGR?

NGR stands for Neutral Grounding Resistor. Use: Limits fault current in grounded systems for protection.

261. What is the full form of NGT?

NGT stands for Neutral Grounding Transformer. Use: Provides grounding for ungrounded systems to limit fault currents.

262. What is the full form of SFRA?

SFRA stands for Sweep Frequency Response Analysis. Use: Diagnostic test to detect mechanical faults in transformers.

263. What is the full form of O&M?

O&M stands for Operation and Maintenance. Use: Refers to running and maintaining electrical equipment efficiently.

264. What is the full form of SPD (in buildings)?

SPD stands for Surge Protective Device. Use: Protects electronics and circuits from surges caused by lightning or switching.

265. What is the full form of XLPE?

XLPE stands for Cross Linked Polyethylene. Use: Insulating material used in modern power cables.

266. What is the full form of PILC?

PILC stands for Paper Insulated Lead Covered. Use: Type of traditional power cable used before XLPE.

267. What is the full form of GCB?

GCB stands for Generator Circuit Breaker. Use: Protects generators from internal and external faults.

268. What is the full form of SMPS?

SMPS stands for Switched Mode Power Supply. Use: Converts electrical power efficiently for electronic devices.

269. What is the full form of LED?

LED stands for Light Emitting Diode. Use: Energy-efficient light source used in homes and industries.

270. What is the full form of CFL?

CFL stands for Compact Fluorescent Lamp. Use: Energy-saving lamp used before LED became popular.

271. What is the full form of LVDC?

LVDC stands for Low Voltage Direct Current. Use: DC distribution system for renewable and smart grids.

272. What is the full form of IEC?

IEC stands for International Electrotechnical Commission. Use: Global standards organization for electrical equipment.

273. What is the full form of IEEE?

IEEE stands for Institute of Electrical and Electronics Engineers. Use: Professional body that develops standards like IEEE 519 for harmonics.

274. What is the full form of ANSI?

ANSI stands for American National Standards Institute. Use: Defines electrical standards in the United States.

275. What is the full form of NEC?

NEC stands for National Electrical Code. Use: Safety code for electrical installations in the U.S.

276. What is the full form of IS Code?

IS stands for Indian Standard. Use: Electrical standards defined by BIS in India.

277. What is the full form of BIS?

BIS stands for Bureau of Indian Standards. Use: Governing body for product certification and standards in India.

278. What is the full form of EMC?

EMC stands for Electromagnetic Compatibility. Use: Ability of equipment to operate without interfering with others.

279. What is the full form of EMI?

EMI stands for Electromagnetic Interference. Use: Disturbance that affects performance of electrical devices.

280. What is the full form of RFI?

RFI stands for Radio Frequency Interference. Use: Interference caused by radio waves affecting circuits.

281. What is the full form of AMF Panel?

AMF Panel stands for Automatic Mains Failure Panel. Use: Switches supply to DG set automatically when mains fail.

282. What is the full form of ATS Panel?

ATS Panel stands for Automatic Transfer Switch Panel. Use: Transfers load between utility and generator.

283. What is the full form of NVR?

NVR stands for No Volt Release. Use: Safety feature that prevents motor from restarting after power failure.

284. What is the full form of DOL?

DOL stands for Direct On Line. Use: Starter type that directly connects motor to supply.

285. What is the full form of STAR-DELTA?

Star-Delta is a motor starter method. Use: Reduces starting current of induction motors.

286. What is the full form of PF?

PF stands for Power Factor. Use: Ratio of real power to apparent power in a circuit.

287. What is the full form of TPM?

TPM stands for Total Productive Maintenance. Use: Maintenance approach used in industries for reliability.

288. What is the full form of MCC Room?

MCC Room stands for Motor Control Center Room. Use: Dedicated room housing motor control panels and starters.

289. What is the full form of ELC?

ELC stands for Earth Leakage Circuit. Use: Detects leakage current for safety.

290. What is the full form of NOC?

NOC stands for Network Operations Center. Use: Central monitoring station for power and communication systems.

291. What is the full form of VSD?

VSD stands for Variable Speed Drive. Use: Controls speed of motors by varying frequency and voltage.

292. What is the full form of HRC?

HRC stands for High Rupturing Capacity. Use: Fuse type that can safely interrupt high fault currents.

293. What is the full form of HVAC?

HVAC stands for Heating, Ventilation and Air Conditioning. Use: Electrical systems that control climate in industrial buildings.

294. What is the full form of DCDB?

DCDB stands for Direct Current Distribution Board. Use: Distributes DC power in solar and telecom systems.

295. What is the full form of ACDB?

ACDB stands for Alternating Current Distribution Board. Use: Distributes AC power to loads in electrical systems.

296. What is the full form of BMS (in buildings)?

BMS stands for Building Management System. Use: Monitors and controls electrical, HVAC, and fire safety systems in buildings.

297. What is the full form of IPMS?

IPMS stands for Integrated Power Management System. Use: Manages power distribution in marine and industrial systems.

298. What is the full form of LUX?

LUX is the unit of Illuminance. Use: Measures brightness of light on a surface.

299. What is the full form of KWH?

KWH stands for Kilowatt Hour. Use: Unit of electrical energy consumption used in billing.

300. What is the full form of AMR?

AMR stands for Automatic Meter Reading. Use: System that collects energy consumption data remotely.