[A] A Ammeter ABB Air-blast Circuit Breaker ABC Automatic Brightness Control ABCB Air-blast Circuit Breaker ABCC Automatic Brightness and Contrast Control AC Alternating Current ACAS Airborne Collision Avoidance System ACB Air Circuit Breaker ACSR Aluminum Cable Steel Reinforced ADC Analog Digital Converter ADF Automatic Direction Finder ADM Adaptive Delta Modulation ADPCM Adaptive Differential Pulse Code Modulation ADS Automation Distribution System ADSL Asymmetric Digital Suscriber Line AF Audio Frequency AFC Automatic Frequency Control AFT Automation Fine Tuning AGC Automation Gain Control AGC Automatic Generation Control AGC Automatic Generation Control AHU Air Handling Unit AI Artificial Intelligence ALD Automatic Load Dispatching ALGOL Algorithmic Language AM Amplitude Modulation AMP Ampere AMP Amplifier AN Annunciator AND And ANSI American National Standard Institute AP Apparent Power APF Active Pass Filter ARQ Automatic Request Question ARS Automatic Route Selection ARU Audio Response Unit AS Ammeter Changer-over Switch ASCII American Standard Code for Information Interchange ASIC Application Specific IC
ASK Amplitude Shift Keying ASP Application Service Provider ASR Automatic Send/Receive set ATC Automatic Temperature Control ATC Automatic Train Control, Automatic Traffic Control ATM Asynchronous Transfer Mode AVM Automatic Vehicle Monitoring system AVR Automatic Voltage Regulator [B] B Battery BA Bridging Amplifier BAS Building Automation System BC Binary Counter BC Battery Charger BCD Binary Coded Decimal 2 10 BCPD Bushing Capacitance Potential Device BCT Bushing -Type Current Transformer BIL Basic Impulse Level BL Bell BL Blower BPD Bushing-Type Potential Device BR Balance Relay BS British Standard BS Button Switch BSO Bismuth Silicon Oxide BST Booster BTL Balanced Transformerless BWG Birmingham Iron Wire Gauge BWO Backward Wave Oscillator BZ Buzzer [C] C Condenser, Capacitor CAD Computer Aided Design CAE Computer Aided Engineering CAI Computer Aided Instruction CAL Computer Aided Learning CALS Commerce at Light Speed
CAM Computer Aided Manufacturing CAPTAIN Character and Pattern Telephone Access Information CAT Computer Aided Testing, Computerized Axial Tomography CATV Cable TV, Community Antenna TV CAV Constant Angular Velocity CB Citizen Band transceiver CB Circuit Breaker CC Closing Coil CCD Charge Coupled Device CCIR International Radio Consultative Committee CCITT International Telegraph and Telephone Consultative Committee CCNR Current Controlled Negative Resistance CCPD Coupling Capacitance Potential Device CCT Compensating Current Transformer CCT Clean Coal Technology CCTV Closed Circuit TV CD-ROM Compact Disk Read Only Memory CDK Communication Deck CDMA Code Division Multiple Access CDRX Critical Damping Resistance External CDT Cyclic Digital Transmission CEP Circular Error Probable CF Coupling Filter CFO Critical Flashover CFF Critical Fusion Frequency CFRP Carbon fiber Reinforced Plastics CH Cable Head CIE Commission International de I'Eclairage CIM Computer Integrated Manufacturing CIGRE Conference International Grandes Reseaux E'lectriques a Haute Tension CLR Current limited Resistor CLR Current Limiting Relay CLX Current Limiting Reactor CM Construction Management CML Current Mode Logic CMRR Common Mode Rejection Ratio CNC Computer Numerical Control COAX Coaxial Cable
COBOL Common Business Oriented Language CODEC COder-DECoder COHO Coherent Oscillator CONACS Control Acquisition & Control System COP Coefficient of Performance COS Cut Out Switch COS Change-over Switch CP Contents Provider CPD Capacitor Potential Device CPU Control Processing Unit CR Current Relay CR Conversion Ratio CRT Cathode Ray Tube CS Change-over Switch CS Control Switch CSD Constant Speed Drive unit CSMA/CD Carrier Sense Multiple Access with Collision Detection CSWR Current Standing Wave Ratio CT Current Transformer CTD Charge Transfer Logic CTD Condenser Trip Device CTL Complementary Transistor Logic CTR Critical Temperature Resistor CTR Controller CTT CT Test Terminal CV CVCF Constant Voltage Constant Frequency CVD Chemical Vapor Deposition method CVVS CWM Coil Water Mixture [D] DAC Digital Analog Converter DAS Distribution Automation System db Decibel DBR Dynamic Braking Resistor DC Direct Current DC Discharging Coil D/C Demand Controller DCL
DCR Differential Current Relay DCS Distributed Control System DDC Direct Digital Control DDC Data Dispatch Computer DF Dumping Factor DFR Differential DG Differential Gain DG/DF Differential Gain/Differential Phase DOCGR Directional Over Current Ground Relay DOCR Directional Over Current Relay DH Double Heterostructure Diff R Differential Relay DIN Deutsche Institut fur Nordmann DL Dummy Load D/L Distribution Line DNC Direct Numerical Control DP Differential Phase DPCM Differential Pulse Code Modulation DPSK Differential Phase Shift Keying DR Discharging Resistor DS Disconnecting Switch DSM Demand Side Management DSP Digital Signal Processor DV DVM Digital Voltmeter DYNAMO Dynamic Model [E] EAPBX EBM EC ECCS ECG ECTL EDC EDM
EDPS EDR EGE system EG-MG system EIA EIBS EIRP EL EL ELD EMC EMD EMF EMG system EMI EMS EMS EPIRB EPRI ESCO ESDD ESP ET EMG (Three Engine system) EV EWS EX EX-D EX-N EX-R 3 ( ) 3 ( ) 3 ( ) [F] F Fuse F Frequency Meter FA Factory Automation FA Forced Air FBCB Fluidised Bed Combustion Boiler FC Frequency Changer, Frequency Converter FCB FCI Flux Changes per Inch
FACTS FCU FCU FD FDDI Flexible AC Transmission System Fan coil unit Field control unit Floppy Disk Fiber Distribution Data Interface FDS Fused Disconnecting Switch FDM Frequency Division Multiplex communication FDMA Frequency Division Multiplex Access FEC Forward Error Correction FCB Field Circuit Breaker FCC Federal Communication Commission FCL Fluorescent Circular Lamp FCR Flicker Relay FDS Fused Disconnecting Switch FET Field Effect Transistor FF Flip Flop FFC Flat Frequency Control FG Frame Ground FGA Floating Gate Amplifier FI Fault Indicator FL Fluorescent Lamp FL Flow Meter FLR Fluorescent Rapid Lamp FLR Flow Relay FLR Field Loss Relay FLT Filter FLTS Float Switch FM Frequency Modulation FMEA Failure Mode Effect Analysis FMS Flexible Manufacturing System FMS Facility Management System FOA Forced Open Air FOT Frequency of Optimum Traffic FORTRAN Formula Translator FPN Future Proof Network FR Frequency Relay FRH Field Regulator, Field Rheostats FRP Fiber glass Reinforced Plastics FS Field Switch FSK Frequency Shift Keying FSS Flying Spot Scanner FTC Fast Time-constant Circuit
FTC Flat Tie-line Control FTS Foot Switch FTTH FTTO Fiber to the Home Fiber TO The Office [G] G Generator Ga-As Gallium Arsenide GCA Ground Control Approach GCB Gas Circuit Breaker GCR Group Coded Recording GCS Gate Controlled Switch GD Ground Detector GIS GIS Gas Insulated Substation Gas Insulated Switch gear GR Grounding Resistor GPT Ground Potential Transformer GPWS Ground Proximity Warning System GSR Grounding Short Circuit Relay G/T Gain over Temperature GT Grounding Transformer GTD Ground Trip Device GTO Gate Turn Off thyristor GGG Godolinium Gallium Garnet, GIS Gas Insulated Switchgear GND Ground GPI Ground Position Indicator GPIB General Purpose Interface Bus GPS Global Positioning System GPSS General Purpose System Simulator GPTE General Purpose Test Equipment GR Ground Relay ( ) [H] H Heater HA Home Automation
HBT Hetero Bipolar Transistor HC Holding Coil HDCC Hard Drawnd Copper Cable HDD Hard Disk Drive HDSL High Data Rate Subscriber Lines HEMT High Electron Mobility Transformer HF High Frequency HIC Hybrid IC HID High Intensity Discharge Hi-Fi High-Fidelity HM Holding Magnet HMI Human Machine Interface HO Horn HPO High Phase Order HRM Hour Meter HSCB High-speed Circuit Breaker HSGS High-speed Grounding Switch HTL High Level Transistor HUD Hz Headup Display Hertz [I] IA Isolation Amplifier IAEA International Atomic Energy Association IAGC Instantaneous Automatic Gain IARU International Amateur Radio Union IAU International Astronomical IBS INTELSAT Business Service IBS Intelligent Building System ICS Indicating Type Contact Switch ICSU International Council of Scientific Unions ICT Insulating Core Transformer IDC Internet Data Center IDF Intermediate Distributing Frame IE Industrial Engineering IEA International Energy Agency IEC International Electro technical Commission IEE Institute of Electrical Engineers(UK)
IEEE Institute of Electrical and Electronic Engineers IEEJ Institute of Electrical Engineering of Japan IF Intermediate Frequency IFRB International Frequency Registration Board IFT Intermediate Frequency Transformer IGBT Insulated Gate Bipolar Transistor IGCC Integrated Gasification Combined-Cycle IGFET Insulated Gate FET FET IIT Indicating type Instantaneous Trip ( ) IL Illuminating Lamp ILD Injection laser Diode INS Information Network System IM Induction Motor IM Integration Motor IMT IMS International Mobile Telecommunication Intelligent Manufacturing System INMARSAT International Marine Satellite Consortium INS Inertial Navigation System IOCS Input Output Control System IP Integer Programming IP Information Provider IPL Initial Program Loader IR Induction voltage Regulator IRS Inertial Reference System ISDN Integrated Services Digital Broadcasting ISN Integrated Service Network ISO International Organization for Standardization ISU International System of Units ITCG International Telecommunication Convention Geneva ITDM Intelligent Time Division Multiplexing ITU International Telecommunication Union IL Integrated Injection Logic IV [J~K] JB BOX Junction Box JEC Japanese Electrotechnical Committee JEM Japanese Electro Technical commission
JFET Junction FET FET JIS Japanese Industrial Standards JISC Japanese Industrial Standards Committee KDP Kalium Dihydrogen Phosphate 2 KODAS Korea Distribution Automation System KR Keep Relay KS Korean Standards KS Knife Switch KSR Keyboard Send/Receive set KTN Kalium Tantalum Niobate kva kw kwh Kilovolt Ampere Kilowatt Kilowatt Hour [L] LA Laboratory Automation LA Lightning Arrester LAN Local Area Network LANER Light Activated Negative Emitter Resistance LAS Light Activated Switch LASCR Light Activated Silicon Controlled Rectifier SCR LCC Life Cycle Cost,GND, LCD Liquid Crystal Display LCU Line Control Unit LD Laser Diode, Laser Disk LDC Line Drop Compensator LDR Loading Resistor LDV Laser Doppler Velocimeter LED Light Emitting Diode LF Low Frequency LFOR Lightning Flashover Rate LFR Loss of Field Relay, Field Loss Relay LID Leadless Inverted Device LIWA Low Impulse withstand Level LNA Low Noise Amplifier LS Line Switch LNG Liquified Natural gas
LS Limit Switch LSI Large Scale Integration LSTTL Low power Shottky Transistor Transistor Logic LTT On-load Tap-changing Transformer LUF Lowest Usable Frequency LVR On-load Voltage Regulator LVS Level Switch [M] M Motor MADT Micro Alloy Diffused Transistor MB Electromagnetic Brake MAIN Multiple_Service Access Integrated Network MAN Medium Area Network MAP Manufacturing Automation Protocol MATV Master Antenna Television MBB Magnetic Blast Circuit Breaker MBB Magnetic Blow-out Circuit Breaker MBB Contact Make Before Break Contact MBB MBE Molecular Beam Epitaxy MBM Magnetic Bubble Memory MC Electromagnetic Contactor MC Metal Clad MCB Molded Case Circuit Breaker MCB MCCB Magnetic Circuit Breaker Metal Clad Circuit Breaker MCCB Molded Case Circuit Breaker MCFC MCL Electromagnetic Clutch MCSG Metal Clad Switch-Gear MCT Magnetic Counter MCTR Master Controller MDA Maximum Demand Ammeter MDF Main Distribution Frame MDI Magnetic Direction Indicator MDS Microcomputer Development System MDW Maximum Demand Wattmeter ME Medical Electronics ME Micro Electronics, Molecular Electronics
MEM Memory MES-FET Metal Semiconductor Field-Effect Transistor MF Medium Frequency wave M/G Motor/Generator set MHD Generation Magneto Hydrodynamics Generation MICR Magnetic Ink Character Reader MIS Management Information System MISIC Metal Insulated Semiconductor IC IC, MKS units Meter Kilogram Second MKS MKSA Meter Kilometer Second Ampere MKS MLV Multi-vibrator MMI Man Machine Interface(operator console) MMS Maintenance Management System MMIC Monolithic Microwave IC MNOS Metal Nitride Oxide Semiconductor MOCVD Organometallic Compound CVD CVD MODEM Modulation&Demodulation MOF Metering Out Fit MOS Metal Oxide Semiconductor MOS FET Metal Oxide Semiconductor FET MOV Motor-operated Valve MPU Microprocessor Unit MTA Maximum Torque Angle MTBF Mean Time Between Failure MTE Mean Time between Error MTTF Mean Time To Failure MTTR Mean Time To Repair MUF Maximum Usable Frequency MUT Mean Up Time MUX Multiplex [N] n Nano N Tachometer NAND Nand NC Numerical Control NCU Network Control Unit
NEMA National Electrical Manufacture Association NdPP Neodymium Pentaphosphate NFB No Fuse Breaker NGR Neutral Grounding Resistor NIS National Information System NLTC Non Load Tap Changer NMR Nuclear Magnetic Resonance NOR Nor NOT Not, Negation NRT No ringing trunk NRZ Non Return to Zero NRZI Non Return to Zero Inverted NTSC System National Television System Committee System [O] OA Office Automation OA Open Aire OBD Optical Bistable Device 2 OCB Oil Circuit Breaker Organization for Economic Cooperation and OCED Development OCGR Over Current Ground Relay OCR Optical Character Recognition OCR Over Current Relay OCS Operation Control System OEIC Optoelectronics Integrated Circuit OEM Original Equipment Manufacturing OF Cable Oil Filled Cable OFT Optical Fiber Tube OLTC On Load Tap Changer, OLTS On Line Test System OLVR On Load Voltage Regulator OMR Optical Mark Reader OMS Ovonic Memory Switch OPC Organic Photo-conductive Cell OPC Operating Coil OPCB Oil Pour Circuit Breaker OPT Out Put Transformer OR Operating Register
OR Or ORM Off Return Memory OS Oil Switch OSR Over-speed Relay OSS Over-speed Switch OSI Open System Interconnection OT Output Trunk OT Oil of Transformer OTC Overcurrent Trip Coil OTF Optical Transfer Function OTL Output Transformerless OCGR Over Current Ground Relay OCR Over Current Relay OL Over Load OLR Over Load Relay OPM Operating Motor OPR Open-phase Relay OVGR Over Voltage Ground Relay OVR Over Voltage Relay OW OWF Optimum Working Frequency [P~Q] PABX Private Automatic Brench Exchanger PAL system PAFC Phase Alternating by Line system PAM Pulse Amplitude Modulation PBX Private Branch Exchange PC Peterson Coil ( ) PCB Printed Circuit Board PCM Pulse Code Modulation PCS Punch Card System PCS PCT PD Primary Cutout Switch Potential Current Transformer, Combined Voltage and Current Transformer Potential Devide PDM Pulse Duration Modulation PDP PE Plasma Display Panel Power Electronics
PF Power Factor PF Power-factor Meter PF Power Fuse pf pico Farad PFBC Pressuried Fluidised Bed Combustion PFM Pulse Frequency Modulation PG Pressure Gauge PHS Personal Handy-phone System PHS PHASE SHIFTER PI Position Indicator PID Proportional-Differential-Integration Control - - PIV Peak Inverse Voltage PLC Programmable Logic Controller PLC Power Line Carrier PLR Polarity Relay PM Phase Modulation PNA Home Phoneline Network Alliance Hone network PNM Pulse Number Modulation POR Position relay POS Pole Type Oil Switch PPM Pulse Phase Modulation PR Protective Ratio PR Plugging relay PR Power Relay PRR Pressure relay PRS Pressure Switch PSALI Permanent Supplementary Artificial Lighting PSK Phase Shift Keying PSS Power System Stabilizer PT Potential Transformer PTM Pulse Time Modulation PTT PT Test Terminal PT PW Piolit Wire PWR Power relay PWM Pulse Width Modulation QAM Quadrature Amplitude Modulation QED Quantum Electro Dynamics
[R] R Ra RAM Resistor Read Access Memory RC Rotary Converter RC Rotary Condenser RC Rupturing Capacity (MVA) RCF Ratio Correction Factor RCR Reclosing relay RCTL Resistor Condenser Transistor Logic RF Radio Frequency RF RECTIFIER RH Rheostat RIF Radio Influence Field RM Retentive Memory RMI Radio Magnetic Indicator RMS value Root Mean Square value ROM Read Only Memory RPM Revolution Per Minute RPR Reverse Power Relay RS Rotary Switch RSTC Reset Coil RT Refrigeration TON RTCF Real Time Control Facility RTD Resistance Temperature Detector RTL Resistor Transistor Logic RTS Request To Send RTU Remote Terminal unit [S] S Switch SAN Storage Area Network SAMOS Stacked Avalanche Injection MOS SAW Surface Acoustic Wave SC Static Condenser SC Control Switch SCAS Supervisory Control Acquisition System SCADA Supervisory Control & Data Acquisition SCL transistor Space Charge Limited transistor
SCR Silicon Controlled Rectifier SCR Short Circuit Ratio SCS Silicon Controlled Switch SCU Substation control unit SD-ACSR Self Damping ACSR SEC Secondary Electron Conduction SEMS Super conducting magnetic storage SEX Sub-Exciter SFFO Shielding Failure Flashover SFR Shift Register SGR Selecting Ground Relay SH Shunt SI System Integration SIL Surge Impedance Loading SiC Silicon Carbide SIP Single In-line Package SIT Silicon Intensifier Target tube SIT Static Induction Transistor SL Signal Lamp, Pilot Lamp SM Synchronous Motor SMB Small/Medium sized Business SMT Schmidt Trigger S/N Ratio Signal & Noise Ratio SOFC SOI Semiconductor On Insulator SOR Out-of-step relay(setp-out relay) SOV Switching Over Voltage SPEFC HO Horn SPL Sound Pressure Level SPR Speed relay SPS Speed Switch SPST Single Pole Single Throw SQUID Super Conducting Quantum Interference Device SR Series Reactor SR Short-circuit relay S/S Substation SSC SS cable Self Supporting cable SSFOR Switching Surge Flashover Rate SSG Standard Signal Generator
SSM Single Shot Multi-vibrator SSPG Spread Solar Power Generator SSR Solide State Relay SSR Sub-Synchronous Resonance STACIR STATCON Static Condenser (FACTS) STC Sensitivity Time Control STR Starting Resistor STT Starter SRT Starting relay SV Solenoid Valve SVC Static var compensator SVR Static Voltage Regulator SY Synchronoscope, Synchronism Indicator SYR Synchronizing relay [T] Tr Transformer TB Terminal Block, Terminal Board, TBC Time Base Correction TBC Tie-line Base Control TC Transmission Control TC Tele-Communication TC Trip Coil TCBR Thyristor Controlled Breaking Resistor(FACTS TCM Time Compression Multiplex TCP/IP Transmission Control Protocol/ Internet Protocol TCPR Thyristor Contorlled Phase Angle Regulator(FACTS TCSC Thyristor Controlled Series Capacitor(FACTS) TCU Transmission Control Unit TD Transmitter Distributor TDB Time Delay(Both) TDD Time Delay De-energizing TDD Total Demand Distortion TDE Time Delay Energizing TDM Time Division Multiplex TDMA Time Division Multiple Access TDR Time delay relay TED Transfer Electron Device
TFT Thin Film Transistor TFR Trip-free relay TG Turbine Generator TG Tachometer Generator TGC Triglycine Sulfate TGS Triglysine Sulphate TH Thermometer THC Thermocouple THD Total Harmonic Distortion THR Thermal relay T/L Transmission Line TLR Time-lag relay TOE TON of oil Equivalence TR Temperature relay TRV Transient Recovery Voltage TS Tumbler Switch TSC Thermally Stimulated Current TSI Threshold Signal to Interface ratio TSI Time Slot Interchange TSL Three State Logic TSS Time Sharing System TT Testing Terminal TTL Transistor Transistor Logic TWT Travelling Wave Tube [U] UCR Under Current Relay UFR Under Frequency Relay UHF Ultra High Frequency UJT Uni-Junction Transistor ULTC Under Load Tap Changer (OLTC) UPS Uninterruptible Power Supply UVC Under-voltage Release Coil, Under-voltage Trip Coil UVR Under Voltage Relay [V] V Voltmeter
VAC Volts Alternating Current VAN Value Added Network VAR Var Meter, Reactive Power Meter VCB Vacuum Circuit Breaker VCM Voice Coil Motor VCR Vacuum relay VCS Vacuum Switch VCO Voltage Controlled Oscillator VDE Verband Deutscher Elektrtechniker VDT Visual Display Terminal VEF Vacuum Electric Furnace VF Converter Voltage Frequency Converter VFD Visual Fluorescent Display VFO Variable Frequency Oscillator VG Vacuum Gauge VHF Very High Frequency VI Vacuum Interrupter VIT Vacuum Interrupter Tube VPI Vacuum Pressure Impregnation VPN Virtual Private Network VoFR Voice over Frame Relay VoIP Voice over Internet Protocol VR Voltage relay VRS Video Response System VS Voltmeter Change-over Switch VSB Vestigial Side Band VSWR Voltage Standing Wave Ratio VTVM Vacuum Tube Volt Meter VU Volume Unit VV VVVF Variable Voltage Variable Frequency [W~Z] W Watt -meter WAN Wide Added Network WAP Wireless Application Protocol WDM Wavelength Division Multiplexing WH Watt-hour Meter WLI Water Level Indicator
WLL Wireless Local Loop LAN WSS Weekly Start-up and stop XMT Transmit XTAL XUV Extreme Ultraviolet radiation YAG Yttrium Aluminum Garnet YDS Star-delta Starter YIG Yttrium Iron Garnet ZCT Zero-Sequence Current Transformer