800+ Electrical & Electronic Abbreviations with Full Forms. A-Z

Electrical and Electronics Engineering Abbreviations with Full Forms 

Below is the list of 800+ short form or abbreviation with full form used in electrical and electronic engineering. All the abreavtion are listed from A to Z and Numerical form in Ascending form. You can press “CTRL + F” and write the short form or paste in search box to go to the exact matching abbreviation with full form.

• Related Post: Electrical and Electronic Engineering Symbols

A

• A                     Amperes, amps.
• A_pp                  Peak-to-peak amperes
• AA                   Anti-Aliasing
• AAAC             All Aluminum Alloy Conductor
• AAC                All Aluminum Conductor
• AACSR          Aluminum Alloy Conductor Steel Reinforced
• AAF                Anti-Aliasing Filter
• ABC                Aerial Bundled Conductors or Cables
• AB switch      Air Break switch
• AC                  Alternating current or voltage
• A/C                 Air Conditioning
• ACAR             Aluminum Conductor Alloy Reinforced
• ACB                Air Circuit Breaker
• ACCB             Air Case Circuit Breaker
• ACDB             Alternating Current Distribution Board
• ACSR             Aluminum Conductor Steel Reinforced
• ACVS             Air Conditioning & Ventilation System
• ADC               Analog to Digital Converter
• AF                   Audio Frequency or Audible Frequency
• AFC                Automated Frequency Control
• AFC                Available Fault Current
• AFCB             Arc Fault Circuit Breaker
• AFCI               Arc Fault Circuit Interrupter
• AFL                 Amps Full Load
• AFT                 Automatic Fine Tuning
• AGC               Automatic Gain Control
• AGME            American Gear Manufacturer’s Association
• AGPS             Assisted (or Aided) GPS
• AH                  Ampere-Hour Capacity of Batteries.
• AHU               Air Handling Unit
• AI                    Analog Input
• AI                    Artificial Intelligence
• AIC                 Ampere Interrupting Capacity
• AL                   Aluminum
• ALCI               Appliance Leakage Current Interrupter
• ALTC              Automatic Load Tap Changing
• ALU                Arithmetic and Logic Unit
• AMOLED       Active Matrix Organic Light Emitting Diode
• ANSI               American National Standards Institute.
• AO                  Analog Output
• AoA                Angle of Arrival
• AOI                 Automatic Optical Inspection
• AP                   Access Point
• APD                Avalanche Photo Diode
• APFC             Automatic Power Factor Control
• API                  American Petroleum Institute, Application Program Interface
• ARM               Advanced Reduced instruction set computing Machine
• ARMS             Arc Flash Reduction Maintenance Switch
• ASCII              American Standard Code for Information Interchange
• ASIC               Application Specific Integrated Circuit
• ASK                Amplitude Shift Keying
• ASME             American Society for Testing and Materials
• ASP                Application Service Provider
• ASTA              Association of Short-circuit Testing Authorities.
• ATS                Automatic Transfer Switch
• ATC                Automatic Temperature Control
• ATMega          Microcontroller Cip created by Atmel in the megaAVR family
• ATMEL           Advanced Technology for Memory and Logic
• AV                   Audio/video
• AVO-M            Ampere-Volt-Ohm Meter
• AVR                Automatic Voltage Regulator
• AWA               Aluminum Wire Armour
• AWG               American Wire Gauge

Related Post: 5000+ Electrical and Electronics Engineering Formulas and Equations

B

• B or b              Electrical Susceptance
• Bar or bar       Pressure in atmospheres.
• BASEEFA     British Approvals Service for Electrical Equipment in Flammable Atmospheres
• BBM               Break before Make
• BCD               Binary Coded Decimal
• BCR               Backspace card reader and Barcode reader
• BER                Bit Error Rate
• BEV                Billion Electron Volts
• BGA                Ball Grid Array
• BIL                  Breakdown insulation level
• BJT                 Bipolar Junction Transistor
• BLAC             Brushless AC
• BLDC             Brushless DC
• BLDM             Brushless DC Motor
• BOM               Bill Of Materials
• BPF                Band Pass Filter
• bps                  Bit per second
• Bps                 Byte per second
• BSI, BS, CP    British Standards Institution, or its publications
• BTS                Base Transceiver Station
• BTU                British thermal unit
• BW                 Bandwidth, (difference between upper and lower limits of a band of frequencies)

C

• C                     Electrical capacitance, Conduit
• CA                  Criticality Analysis
• CAAPS          Circuit Assembly And Processing System
• CACA             Totally enclosed air circuit, air cooled.
• CACW            Totally enclosed air circuit, water cooled.
• CAD               Computer aided design.
• CAN               Controller area network
• CATV             Cable Television or Community Antennae Television
• CB                  Circuit breaker
• CBCU            Circuit breaker control unit.
• CBI                 Complementary Binary, referring to a system of codes
• CBM               Certified Ballast Manufacturer
• CBR               Constant Bit Rate
• CC                  Constant Current
• CCCS             Current Controlled Current Source
• CCD               Charge-Coupled Device
• CCR               Central control room
• CCT                Circuit (also: CIR, CKT)
• CCTV             Closed Circuit Television
• CCU               Central control unit
• CD                  Candela
• CDMA             Code Division Multiple Access
• CEGB             Central Electricity Generating Board (UK)
• CENELEC      European Committee for Electro technical Standardization
• cont.               Continuous quantity
• CFL                Compact Fluorescent Light or Compact Fluorescent Lamp
• CG                  Cable Glands
• CIR                 Circuit (also: CCT, CKT)
• CISC              Complex Instruction Set Computer
• CKT                Circuit (also: CCT, CIR)
• CLF                Current Limiting Fuse
• CMOS            Complementary Metal – Oxide Semiconductor
• CMRR             Common Mode Rejection Ratio
• CNC               Computer Numeric Control
• COG               Chip-on-glass
• COR CU        Corrugated Copper.
• Cos θ             Power factor.
• CPLD             Complex Programmable Logic Device
• CPT                Control Power Transformer
• CPU               Central Processing Unit
• CRO               Cathode Ray Oscilloscope
• CRT                Cathode Ray Tube
• CSA, csa       Cross-Sectional Area
• CSI                 Current Source Inverter
• CSP                Chloro Sulphonated Polyethylene
• CSS                Computerized Synchronizing System
• CT                   Current Transformer
• CU                  Un-tinned Copper
• CUWB            Copper Wire Braid
• CVT                Constant Voltage Transformer

D

• d                     Day.
• DAC               Digital to Analog Converter
• db(A)              Measurement unit of sound, Decibels, absolute.
• dBm               Unit level for power ratio expressed in decibels (dB) with reference to one mill watt (mW)
• DB                  Distribution Board
• DC                  Direct Current or Voltage
• DCDB             Direct Current Distribution Board
• DCS               Distributed Control System
• DE                  Drive End of a shaft
• DEMUX         Demultiplexer, Single input into multiple outputs
• DFT                Discrete Fourier Transform
• DIA                 Diameter
• DIMM              Dual-In-line Memory Module
• DIN                 Deutsches Institut für Normung means German Institute for Standardization
• DIP                 Dual-in-Line Package
• DIPS               Dual-In-Line Sockets
• DLD                Digital Logic Design
• DLL                 Delay Locked Loop
• DMA               Direct Memory Access
• DMM               Digital Multimeter
• DMS               Data management system
• DMT                Definite minimum time
• DNC               Do Not Connect
• DO fuse         Drop Out Fuse
• DOL                Direct-on-line starting of induction motors.
• DOS               Disk Operating System
• DP                  Double Pole or Distribution Panel 
• DPDT             Double Pole, Double Throw
• DPI                 Dots Per Inch
• DPIC              Double Pole Iron Clad
• DPM               Digital panel meter
• DPR               Dividing Pulse Relay
• DPST             Double Pole, Single Throw
• DRAM             Dynamic Random Access Memory
• DRC               Design Rule Checking
• DSP                Differential Signal Processing
• DTMF             Dual Tone Multi-Frequency
• DTL                 Diode Transistor Logic
• DTSP             Discrete Time Signal Processing
• DUT                Device Under Test
• DVM               Digital Volt Meter
• DWR              Divided winding rotor synchronous generator.

E

• E                     Earth or ground
• EB                   Equipment Branch
• EBIC               Electron-Beam-Induced Current
• EC                  Electrical Code or Electrical Contractor or Electronic Commutator
• ECAD             Electronic Computer-Aided Design
• ECHA             Equipment certified for hazardous areas.
• ECL                Emitter coupled logic
• EEC                European Economic Community
• EEMVA          Engineering Equipment and Materials Users Association
• EEPROM       Electrically Erasable Programmable Read-Only Memory
• EF                   Exhaust Fan
• EFT                 Electrical fast transient
• EHT                Extra High Tension
• EHV                Extra high voltage
• EIEMA            Electrical Installation Equipment Manufacturer’s Association (UK)
• ELCB              Earth Leakage Circuit Breaker
• ELDC             Electric Double-Layer Capacitors (supercap)
• ELEV              Elevator
• ELV                Extra low voltage, less than 51 volts
• EM                  Emergency
• EMA               Ethylene methyl acrylate
• EMC               Electromagnetic compatibility
• EMI                 Electromagnetic interference
• EMF, e.m.f.    Electromotive force
• EMLDB          Emergency Lighting Distribution Board
• EMR               Electro Mechanical Relay
• EMT                Electrical Metallic Tubing
• EOCR              Electronic Overcurrent Relay
• EOS                Electrical Over Stress
• EP                   Emergency Power
• EPDM            Ethylene propylene diene monomer
• EPO                Emergency Power Off (Button or Switch)
• EPR                Ethylene propylene rubber
• EPROM         Erasable Programmable Read-Only Memory
• ERA                Electrical Research Association (UK)
• ERM               Electronic restart module
• ESD                Emergency shutdown, Electrostatic discharge
• ESL                Equivalent Series Inductance
• ESP                Electric submersible pump
• ESR                Equivalent Series Resistance
• EST                Extra Super Tension
• Ex (), Ex ‘ ’     Certification symbol for hazardous area equipment.
• EEx (), EEx ‘ ’ Certification symbol for hazardous area equipment, with European harmonisation of standards.
• EV                   Electron volt, a unit of energy similar to joules
• EWC               Electric Water Cooler
• EWS               Engineering work station.

F

• F, f or Hz        Frequency, Fuse, Farad
• FA                  Fire Alarm
• FAA                Fire Alarm Annunciator
• FAT                 Factory acceptance testing
• FBA                Factory built assemblies.
• FBT                 Fly back Transformer
• FCEV             Fuel Cell Electric Vehicle
• FCU                Feeder control unit.
• FDM               Frequency Division Multiplexing
• FDNR             Frequency Dependent Negative Resistor
• F and G          Fire and Gas
• FEED             Front-end engineering and design of a project.
• FET                Field Effect Transistor
• FFC                Flexible Flat Cable
• FFT                 Fast Fourier Transform
• FIFO               First-In, First-Out (a queue)
• FILO               First-In, Last-Out (a stack)
• FLA                 Full Load Amperes
• Flex                Flexible, used for cables.
• FM                  Frequency Modulation
• FMC               Flexible Metal Conduit
• FPGA             Field-Programmable Gate Array
• Freq                Frequency
• FRLS              Fire Resistance Low Smoke
• FSC                Final Sub Circuit
• FSM                Finite State Machine
• FSK                Frequency Shift Keying
• FVC                Frequency to Voltage Converter

G

• G or g             Electrical conductance, or ground
• GBW               Gain Bandwidth Product
• GCB               Gas circuit breaker.
• GCP               Generator control panel.
• GFCI               Ground Fault Circuit Interrupter
• GFI                  Ground Fault Interrupter
• GIC                 Generalized Impedance Converter
• GIS                 Gas insulated switchgear.
• gm                   Transconductance
• GND               Ground
• GO                  Gang Operated
• GOR               Gas to oil ratio of oil well fluids
• GOS               Group Operated Switches
• GPIO              General Purpose Input / Output
• GPRS             General Packet Radio Service
• GPS                Global Positioning System
• GRMC            Galvanized Rigid Metal Conduit
• GRP               Glass reinforced plastic.
• GSM               Global System for Mobile Communications
• GSWA            Galvanized steel wire armour
• GSWB            Galvanized steel wire braid.
• GTG or GT     Gas-turbine generator
• GTO                Gate turn off thyristor
• GUI                 Graphic User Interface

H

• h or hr            Hour.
• HART             Highway Addressable Remote Transducer
• HBT                Heterojunction bipolar transistor
• HCL                Hydrogen chloride, gas or acid
• HDMI              High-Definition Multimedia Interface
• HED               Hall Effect Device
• HEMT             High-electron-mobility transistor
• HF                   High frequency
• hFE                Large-signal current gain of a BJT
• HMI                 Human Machine Interface
• HOA               Hand-Off-Automatic Switch
• HOFR             Heat and oil resisting, flame retardant.
• Hp                   Horse power, unit of power in fps system
• HPF                High Pass Filter
• HRC               High rupturing capacity
• HT                   High Tension
• HTS                High-temperature semiconductor
• HUI                 Human User Interface
• HV                  High voltage, above 600 volts
• HVAC             Heating ventilation and air conditioning
• Hz                   Frequency in cycles per second, or hertz

I

• I                       Current in amperes
• IAC or Iac       Alternating current
• IALA               International Association of Lighthouse Authorities
• IC                    Integrated circuit
• ICDB              Iron Clad Distribution Board
• ICI                   Imperial Chemical Industries plc (UK)
• ICSP               In Circuit Serial Programming
• ICTP               Iron Clad Triple Pole
• IDC, Idc          Direct current
• IDMT               Inverse definite minimum time
• IEC                 International Electrotechnical Commission
• IEE                  Institution of Electrical Engineers of UK
• IEEE               Institute of Electronic and Electrical Engineers of USA
• IF                     Intermediate Frequency
• IFT                  Inverse Fourier Transform
• IG                    Isolated Ground
• IGBT               Insulated-gate Bipolar Transistor
• IGFET             Insulated Gate Field Effect Transistor
• I/O                   Input or output signals or quantity
• IOT                  Internet of Things
• IMO                 International Maritime Organization
• IMC                 Intermediate Metal Conduit
• IMCS              Integrated motor control system
• IMS                 Information management system
• inst.                 Instantaneous quantity
• INT                  Interlock
• int.                   Intermittent quantity
• IP                    Institute of Petroleum (UK) and its publications
• IP                    Ingress protection code, see IEC60529
• IPMSM           Interior Permanent Magnet Synchronous Motor
• IR                    Insulation resistance
• IS                    Intrinsically safe signal, circuit or equipment
• Is/In, IS/IN      Ratio of starting current to running current
• ISO                 International Standards Organization
• ISP                  Internet Service Provider
• ITU                  International Telecommunication Union

J

• J                      Energy in joules or newton-meters
• J                      Current density, amps/mm2
• JB                   Junction Box
• JFET               Junction field effect transistor
• JEDEC           Joint Electron Device Engineering Council

K

• kA                   Kilo-amperes
• KCL                Kirchhoff’s Current Law
• KCMIL            Thousand Circular Mils
• KEMA             Short circuit testing authority in The Netherlands
• kg                    Kilogram.
• km                   Length in kilometers
• kpm                 Kilometers per hour.
• kV, Ku            Kilo-volts.
• kVA                 Kilo-volt-amperes.
• kVAr               Reactive kilo-volt-amperes.
• KVL                Kirchhoff’s Voltage Law
• kW                  Kilowatts.
• KWH               Kilo Watt Hour

L

• L                      Electrical inductance in henries
• L                      Line (Phase, Live or Hot) or local control operation
• LA                   Lightning Arrester
• LAN                Local area network
• lbs                   Weight of a substance in pounds.
• LCD                Liquid-crystal display
• LDB                Lighting Distribution Board
• LDR                Light Dependent Resistor
• LDS                Low density foam
• LED                Light emitting diode
• LEL                 Lower explosive limit
• LF                   Low frequency
• LFMC             Liquid Tight Flexible Metal Conduit
• LHS                Left-hand side
• Li–ion             Lithium Ion, a type of rechargeable battery
• Lloyds            Lloyds Register of Shipping (UK)
• LMS                Load management system
• LNA                Low noise amplifier
• LNG                Liquefied natural gas
• loc or (L)         Local operation
• LOP                Loss of power
• LOPT              Line Output Transformer
• LOS                Loss of signal
• LPF                 Low Pass Filter
• LPG                Liquefied petroleum gas
• LPS                Lightning Protection System
• LRA                Locked Rotor Amperes
• LSB                Least Significant Bit
• LSDS, LSS    Load shedding system
• LSF                 Low smoke and fumes, applied to cables and wires.
• LSI                  Large-scale integration
• LSLH              Low smoke low halogen
• LSRS, LSR   Load sharing system
• LT                    Low Tension
• LTG                 Lighting
• LV                   Low voltage, 50 to 600 volts
• LVDT              Linear Variable Differential Transformer
• L1, L2, L3, N Notation for line and neutral voltages and currents.
• LUT                 Look Up Table
• LUX                Level of illumination
• LVDT              Linear Variable Differential Transformer

M

• m                     Length or dimension in meters, or month
• mA                  Current in milli-amperes
• MAD               Mean Annual Discharge
• man or (M)     Manual operation
• mbar               Milli-bar
• MB                  High-pressure mercury, without phosphor coating
• MB                  Megabyte, a computer date storage unit
• MBB               Make-before-break
• MBF                High-pressure mercury, with phosphor coating
• MBFR             High-pressure mercury, with phosphor coating and internal reflector
• MBI                 High-pressure discharge with metallic halides
• MBIF               High-pressure discharge with metallic halides, with phosphor coating
• MBR               Double-ended linear arc tube
• MBTF             Combination of MBF lamp and a filament lamp
• MC                  Metal Clad Cable
• MCB               Miniature circuit breaker.
• MCC               Motor control center
• MCCB            Moulded case circuit breaker
• MCM               Multi-Chip Module
• MCP               Motor Circuit Protection
• MCR               Maximum continuous rating
• MCU               Motor control unit
• MCu               Microcontroller
• MDB               Main Distribution Board
• MEC               Micro Energy Cell
• MEMS            Micro ElectroMechanical Systems
• MESFET        Metal-Semiconductor Field-Effect-Transistor
• MESG            Maximum experimental safe gap
• MF                  Multiplying Factor
• MFSK             Multiple frequency-shift keying
• Mho                Unit of electrical admittance
• MI                    Mineral Insulated
• MIC                 Minimum ignition current
• MICC              Mineral insulated calendar cable
• MIDI                Musical Instrument Digital Interface
• MIMIC             Mimic display panel
• MISO              Master Input Slave Output
• MLDB             Main Lighting Distribution Board
• MLO                Main Lugs Only
• mm                 Length or dimension in millimeters
• MMF, mmf       Magneto-motive force
• MMI                 Man–machine interface.
• MMSCF           Million standard cubic feet of a gas
• Mole %           Molecular weight in %
• MOSFET        Metal Oxide Semiconductor Field Effect Transistor
• MOSI              Master Output Slave Input
• MOV               Metal oxide varistor
• MPCB             Motor Protection Circuit Breaker
• MPDB            Main Power Distribution Board
• MPPT             Maximum Power Point Tracking
• MPU               Microprocessor
• MS                  Main Switch
• MSB               Most Significant Bit
• MSW              Module steelwork
• MT                   Mica glass tape
• MTBF              Mean time between failures
• MTTR             Mean time to repair
• MUX               Multiplexer, several analog or digital inputs into single output
• MV                  Medium voltage
• mV                  Voltage in millivolts
• MVA               Mega-volt-amperes
• MVAr              Reactive mega-volt-amperes
• MW                 Megawatts

N

• N or n             Number of items e.g. generators installed
• N or n             Number of turns in a winding
• N or n             Neutral terminal or line Neutral
• NACE             National Association of Corrosion Engineers (USA)
• NBR               Nitrile butadiene rubber
• NC, N/C         Normally closed switching device, No Connection
• NCT                Neutral Current Transformer
• NDE               Non-drive end of a shaft.
• NEC               National Electric Code (USA)
• NEMA            The National Electrical Manufacturer’s Association (USA)
• NER               Neutral earth resistor.
• NFPA              National Fire Protection Association (USA)
• Ni                    Nickel metal
• NL                   Neutral Link, Night Light
• NO, N/O         Normally open switching device
• NOx                Nitrogen based gas emissions.
• NPR               Noise-power ratio
• NPT                National pipe threads (USA).
• NRZ                Non Return to Zero
• NS                  Used to describe a type of variable speed AC motor
• NTC                Negative Temperature Coefficient
• NTS                Not to scale
• NVM               Non Volatile Memory

O

• O                    Open, off or stop
• OC, O/C         Overcurrent or open circuit
• OCB               Oil circuit breaker
• OCTC             On-circuit Tap Changer
• OCV               Open Circuit Voltage, the difference in electrical potential when disconnected from a circuit
• OF, O/F          Over frequency
• OFAF              Forced circulation of internal liquid, forced heat exchanging to external air.
• OFAN             Forced circulation of internal liquid, natural heat exchanging to external air.
• OHL, OHLine Overhead line
• Ohms              Unit of electrical resistance or impedance
• OIM                 Offshore installation manager
• OL, O/L           Overload
• OLED             Organic light-emitting diode
• OLP                OverLoad Protection
• OLR                OverLoad Relay
• OLTC              On-load Tap Changer
• ONAF             Naturally circulated internal liquid, forced heat exchanging to external air
• ONAN            Naturally circulated internal liquid, natural heat exchanging to external air
• OpAmp           Operational Amplifier
• OSC               Oscillator
• OSHA             Occupational Health and Safety Administration (USA)
• OTA                Operational Transconductance Amplifier
• OV, O/V          Overvoltage.
• OVP                Overvoltage Protector

P

• P or W            Active power, watts, Pole
• p, s                  Laplace operator in mathematics, for transfer functions
• P & ID             Piping and instrument diagram
• PA                   Public address system
• PAL                Programmable Array Logic
• PAM               Pulse or pole amplitude modulation
• PB                   Push Button or Panic Button or Pull Box
• PB, Pb            Lead metal
• PBWB            Phosphor bronze wire braid
• PBCU, TCU   Tinned copper
• PC                  Programmable controller, Program counter; used in microcontroller
• PCB               Printed circuit board
• PCC               Point of common connection, Power Control Centre
• PCM               Pulse-code modulation
• PDA                Personal digital assistant
• PDB                Power Distribution Board
• PDM               Pulse density modulation
• PDP                Power Distribution Panel
• PEC                PhotoElectric Cell
• PELV              An extra-low voltage system similar to SELV but connected to earth at some point
• PF, pf              Power factor
• PFD                Phase/frequency detector
• PFM                Pulse Frequency Modulation
• PGA                Programmable Gain Amplifier
• Ph, ph            Phases of an electrical circuit
• PID                 Proportional, Integral, Derivative. A type of controller used in control systems
• PIR                 Passive Infrared Sensors
• PIV                  Peak Inverse Voltage
• pk, peak         Peak value of an instantaneous quantity
• PLA                Programmable logic array
• PLC                Programmable logic controller
• PLCC             Plastic Leaded Chip Carrier
• PLL                 Phase-Locked Loop
• PM                  Permanent Magnet
• PMIC              Power Management Integrated
• pMOS             P-channel metal-oxide semiconductor
• PMS               Power management system
• PMSM            Permanent Magnet Synchronous Motor
• PNL                Panel
• POL                Polyethylene, Point-of-load
• POR               Power-on reset
• Pot                  Potentiometer
• POV                Peak Operating Voltage
• PPM               Pulse Position Modulation, Parts Per Million
• PRC               Parasitic resistance cancellation
• PRV                Peak Reverse Voltage
• PSI                  Pounds per Square Inch
• PSK                Phase Shift Keying
• PSR                Power-supply rejection
• PSRR             Power Supply Rejection Ratio
• PT                   Potential Transformer
• PTB                Physilalish Technische Bundesanstalt
• PTC                Positive Temperature Coefficient
• PTP                Polyethylene terephthalate
• PTFE              Poly tetra fluoro ethylene
• Pu, p.u.          Per unit
• PUT                Programmable Unijunction Transistor
• PV                  PhotoVoltaic
• PVC                Polyvinyl chloride
• PVDF             Polyvinylidene fluoride
• PWD               Pulse-width distortion
• PWM              Pulse width modulation
• PWR               Power

Q

• Q                     Reactive power, volt-amperes-reactive, Charge
• QA                  Quality assurance
• QAM               Quadrature amplitude modulation
• QC                  Quality control
• QFP                Quad Flat Package
• QTY                Quantity

R

• R or r              Electrical resistance
• Rad, rad         Angular displacement in radians
• RADAR          Radio Detection and Ranging
• RAM               Random access memory
• RCBO             Residual Current Circuit Breaker with Overload Protection
• RCCB            means Residual Current Circuit Breaker
• RCD               Residual current device
• RCU               Remote control unit
• RDOL             Reverse Duty On Line Starter
• Ref.                 Reference
• rem or (R)      Remote operation
• REQ               Required
• RF                   Radio Frequency, describing the rate of oscillation
• RFDS             Radio frequency design system
• RFID               Radio Frequency Identification
• RGB               Red Green Blue
• RGS               Rigid Galvanized Steel Conduit
• RHS               Right-hand side
• RIO                 Remote Input Output
• RISC              Reduced Instruction Set Computer
• RJ45               Registered Jack 45. An 8 pin Ethernet Jack
• RLA                Rated Load Amperes
• RLC                Resistance Inductance Capacitance
• RMC               Rigid Metal Conduit
• RMG               Ring Main Gear
• RMS, rms       Root mean square
• RMU               Ring main unit
• RNC               Rigid Non-Metallic Conduit
• ROM               Read only memory
• RPR               Reverse Power Relay
• RPS                Revolutions per Second
• RPM               Revolutions per Minute
• RSC               Rigid Steel Conduit
• RTC                Real-time clock
• RTD                Resistance temperature detector
• RTOS             Real Time Operating System
• RTS                Remote Test Station
• RTU                Remote transmitter unit, Roof Top Unit
• Rx                   Receiver
• RYB                Red, Yellow, Blue (Old Color Codes used for three phase Wiring – UK)

S

• S                     Apparent power in volt-amperes
• s or p              Laplace operator in mathematics, for transfer functions
• S                     Slip of a rotating machine with respect to 1.0 pu
• SAW               Surface Acoustic Wave
• SB                   Switch Board
• SBM               Single buoy mooring
• SC, S/C          Short circuit
• SCADA          Supervisory control and data acquisition system
• SCF                Standard cubic feet of a gas
• SCIM              Squirrel Cage Induction Motor
• SCK                Serial Clock
• SCR               Silicon Controlled Rectifier
• SCS                Silicon Controller Switch
• SCSI               Small Computer System Interface
• SDR               Single discipline review
• SEB                Service End Line Box or Service Electrical Box
• SECT              Skin effect current trace heating
• SELV              Safety extra-low voltage
• SFU                Switch Fuse Unit
• SF6                 Sulphur hexafluoride
• SI                    System International of Unit’s
• SIM                 Subscriber identity module
• SIO                 Serial Input and (serial) Output
• SIPO               Serial In Parallel Out
• SLDB             Secondary Lighting Distribution Board
• SLI                  Double-ended, linear arc tube
• SMD               Surface Mount Device
• SMPS             Switch-mode power supply
• SMSB             Sub Main Switchboard
• SMT                Surface mount technologies
• SNR               Signal-to-Noise Ratio
• SoC                System on a Chip
• SOIC              Small Outline Integrated Circuit
• SOLAS           Safety of life at sea, a document relating to marine practice
• SON               Diffused ellipsoidal outer bulb, single-ended lamp
• SONAR          SOund NAvigation and Ranging
• SON-T            Clear tubular outer bulb, single-ended lamp
• SON-TD, – L Clear tubular outer bulb, double-ended lamp
• SON-R           SON lamp, with internal reflector
• SOL CU         Solid copper
• SOP                Small Outline Package
• SOT                Small outline transistor
• SOX                U-shaped arc tube, single-ended lamp
• Sox                 Sulphur based gas emissions
• SP                   Single phase
• SPDT             Single Pole Double Throw
• SPI                  Serial Peripheral Interface
• SPICE            Simulation Program with Integrated Circuit Emphasis
• SPMSM         Surface Permanent magnet Synchronous Motor
• SPST              Single Pole Single Throw
• SPT                Stranded Parallel Thermoplastic
• sq                    Square, e.g. sq mm is square millimeters
• SR                  Shift Register, Slew Rate
• SRAM             Static Random Access Memory
• SRF                Self-resonant frequency
• SRIM              Slip Ring Induction Motor
• SRM               Switched Reluctance Motor
• SSB                Single SideBand
• SSI                  Small Scale Integration
• SSR                Solid State Relay, Synchronization check protection relay
• ST                   Super Tension, Shunt Trip
• STA                Steel Tape Armoure
• STG                Steam turbine generator
• STP                Shielded Twisted Pair
• STR                Statimax Trip Release
• STR CU         Stranded copper
• SW                  Switch, Shortwave, as in the case with shortwave bands
• SWA               Steel wire armour
• SWBD            Switchboard
• SWG               Standard Wire Gauge
• SWGR            Switchgear
• SYNC, Sync  Synchronizing
• SYM               Symmetrical
• SyRM             Synchronous Reluctance Motor

T

• T or t               Time, usually in seconds
• TB                   Terminal Block
• Td                    Time constant in seconds for the quantity ‘d’
• TC                  Temperature Coefficient
• TCP/IP           Transmission Control Protocol/Internet Protocol
• TDRM             Time delayed restart relay
• TEFC              Totally enclosed fan cooled
• TEL                 Telephone
• TEM                Transverse Electromagnetic (wave)        
• temp.              Temperature
• TESFC           Totally enclosed separate fan cooled, fan attached to an auxiliary motor Shaft
• TF                   Transfer Function
• T/F                  Transformer
• TFD                Thin Film Detector
• TFT                 Thin Film Transistor
• TG                   Turbo-generator, gas or steam
• TGB                Telecommunications Grounding Bus bar
• THD                Total Harmonic Distortion
• THF                Telephone harmonic factor
• TOP                Gas-turbine operating temperature (hot-end blade temperature)
• TM                   Technical measurement system of units
• TMCB             Thermal Magnetic Circuit Breaker
• TCP                Gas-turbine control panel
• TLX                 Cold starting tubular fluorescent lamp, with single-pin caps
• TPDT              Triple Pole Double Throw
• TPIC               Triple Pole Iron Clad
• TPN                Three-phase and neutral power supply
• TPPL              Total plant peak load
• TPRL              Total plant running load
• TPS                Triple Pole Switch
• TPST              Triple Pole Single Throw
• Tran., Tx         Transformer
• TRS                Tough Rubber Sheathed
• TTL                 Transistor-Transistor Logic
• TVS-Diode    Transient Voltage Suppression Diode
• Tx                    Transmitter

U

• U                     Voltage, also used for energy
• UART             Universal Asynchronous Receiver and Transmitter
• UC, U/C         Undercurrent
• UCP               Unit control panel
• UDS               Uniform Drawing System
• UEL                Upper explosive limit
• UF, U/F          Under frequency
• UG                  Under Ground
• UHF                Ultra high frequency
• UI, U/I             Undercurrent
• UJT                 Unijunction Transistor
• UL, U/L           Under load
• UL                   Underwriters Laboratory (USA)
• UVLO             Under voltage lockout
• UNO               Unless noted otherwise
• UPS                Uninterruptible power supply unit
• USART           Universal Synchronous and Asynchronous Receiver and Transmitter
• USB                Universal Serial Bus
• UTP                Unshielded Twisted Pair
• UV, U/V          Under voltage

V

• V, U                Voltage or volts
• VA                   Volt-amperes
• VAC, Vac       Alternating voltage
• VAr, Var         Reactive volt-amperes
• VCA                Voltage Controlled Amplifier
• VCB                Vacuum Circuit Breaker
• VCC               Voltage at the common collector
• VCCS             Voltage Controlled Current Source
• VCD               Variable Capacitance Diode
• VCO               Voltage Controlled Oscillator
• VCXO             Voltage-Controlled Crystal Oscillator
• VDC, Vdc      Direct voltage
• VDE                Verband Deutscher Electrechniker (Germany).
• VDI                 Verein Deutscher Ingenieure (Germany).
• VDU               Visual display unit
• VFD                Variable Frequency Drive, Vacuum Fluorescent Display
• VFDP             Variable Frequency Drive Panel
• VFO                Variable-frequency oscillator
• VGA                Video Graphics Adapter
• VHF                Very high frequency
• VIR                 Vulcanized Indian Rubber
• VLSI               Very Large Scale Integration
• VOM               Volt Ohm Meter, a device also known as a millimeter or multitester
• VSD, VSDS  Variable speed drive systems
• VSI                  Voltage source inverter
• VSWR            Voltage Standing Wave Ratio
• V.T., VT          Voltage transformer
• v/v                   Comparison by volume, per-unit
• VVVF               Variable Voltage Variable Frequency Drive

W

• W or P            Active power, watts
• w or ω            Frequency in radians per second.
• wdg.                Winding of a machine or transformer
• WH                 Water Heater
• WHRU           Waste heat recovery unit
• WLAN            Wireless Local Area Network
• WP                  Weather Proof
• WRIM             Wound Rotor Induction Motor
• WRSM           Wound Rotor Synchronous Motor
• WSN               Wireless Sensor Network

X

• X                     Electrical reactance
• XFMR             Transformer
• XLPA              Cross-linked polyalkene
• XLPE              Cross-linked polyethylene
• XO                  Crystal Oscillator

Y

• Y                     Electrical admittance (Also used for Star Connection)
  
• y                      Year

Z

• Z                      Electrical impedance
• ZH                   Zero halogen, as used for cables
• ZVC                Zero voltage crossing
• ZVS                Zero voltage switching

Numerical

• 1P, SP            Single phase
• 3P                   Three-phase supply
• 3P-N               Three-phase and neutral supply
• 3P-N-E           Three-phase neutral and earth supply
• 2W                  Two-wire supply
• 3W                  Three-wire supply
• 4W                  Four-wire supply
• 3G                   Third Generation
• 3R3                 3.3 ohm Resistor
• 4K                   4,000 pixels
• 4P4T               Quad-Pole Quad-Throw
• 4WJ                Four-Way Junction

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