Published On: Sun, Jun 19th, 2022

Abbreviations Commonly used in Electrical Documents

Jankovic borrowed from: Handbook of Electrical Engineering: For Practitioners in the Oil, Gas and Petrochemical Industry. Alan L. Sheldrake

A Amperes, amps.
A.C. or AC or a.c. Alternating current or voltage.
ACB Air circuit breaker.
ACSR Aluminium conductor steel reinforced.
AGME American Gear Manufacturer’s Association
AH Ampere-hour capacity of batteries.
ANSI American National Standards Institute.
API American Petroleum Institute.
ASTA Association of Short-circuit Testing Authorities.
ASME American Society for Testing and Materials.
AVR Automatic voltage regulator.
AWA Aluminium wire armour.

B or b Electrical susceptance.
Bar or bar Pressure in atmospheres.
BASEEFA British Approvals Service for Electrical Equipment in Flammable
BIL Breakdown insulation level.
BSI, BS or CP British Standards Institution, or its publications.
Btu British thermal unit.

C Electrical capacitance.
CACA Totally enclosed air circuit, air cooled.
CACW Totally enclosed air circuit, water cooled.
CAD Computer aided design.
CB Circuit breaker.
CBCU Circuit breaker control unit.
CCR Central control room.
cct. Circuit.
CCU Central control unit.
CEGB Central Electricity Generating Board (UK).
CENELEC European Committee for Electrotechnical Standardisation.
cont. Continuous quantity.
COR CU Corrugated copper.
Cos φ Power factor.
CPU Central processing unit.
CSA or csa Cross-sectional area.
CSI Current source inverter.
CSP Chloro-sulphonated polyethylene.
CSS Computerised synchronising system.
C.T. or CT Current transformer.
CU Un-tinned copper.
CUWB Copper wire braid.

d Day.
db(A) Measurement unit of sound, Decibels, absolute.
D.C. or DC or d.c. Direct current or voltage.
DCS Distributed control system.
DE Drive end of a shaft.
deg C or ◦C Thermal temperature in degrees Celsius or Centigrade.
deg F or ◦F Thermal temperature in degrees Fahrenheit.
deg K or ◦K Thermal temperature in degrees Kelvin.
DIN Verein Deutscher Ingenieure.
DMS Data management system.
DMT Definite minimum time.
DnV Det Norsk Veritas (Norway).
DOL or D.O.L. Direct-on-line starting of induction motors.
DWR Divided winding rotor synchronous generator.

E Earth or ground.
ECHA Equipment certified for hazardous areas.
EEC European Economic Community.
EEMVA The Engineering Equipment and Materials Users Association.
EHV Extra high voltage.
EIEMA The Electrical Installation Equipment Manufacturer’s Association (UK).
ELCB Earth Leakage Circuit Breaker.
ELV Extra low voltage, less than 51 volts.
EMA Ethylene methyl acrylate.
EMC Electromagnetic compatibility.
EMI Electromagnetic interference.
EMF or e.m.f. Electromotive force.
EPDM Ethylene propylene diene monomer.
EPR Ethylene propylene rubber.
ERA Electrical Research Association (UK).
ERM Electronic restart module.
ESD Emergency shut down.
ESP Electric submersible pump.
Ex () or Ex ‘ ’ Certification symbol for hazardous area equipment.
EEx () or EEx ‘ ’ Certification symbol for hazardous area equipment, with European harmonisation of standards.
EWS Engineering work station.

F, f or Hz Frequency.
FBA Factory built assemblies.
FCU Feeder control unit.
F and G Fire and Gas.
FEED Front-end engineering and design of a project.
Freq. Frequency.
FAT Factory acceptance testing.
Fig. Figure.
Flex Flexible, used for cables.

G or g Electrical conductance, or ground.
GCB Gas circuit breaker.
GCP Generator control panel.
GIS Gas insulated switchgear.
GOR Gas to oil ratio of oil well fluids.
GRP Glass reinforced plastic.
GSWA Galvanised steel wire armour.
GSWB Galvanised steel wire braid.
GTG or GT Gas-turbine generator.
GTO Gate turn off thyristor.

h or hr Hour.
HCL Hydrogen chloride, gas or acid.
HF High frequency.
HOFR Heat and oil resisting, flame retardant.
HRC High rupturing capacity.
HV High voltage, above 600 volts.
HVAC Heating ventilation and air conditioning.
Hz Frequency in cycles per second, or hertz.

I Current in amperes.
IAC or Iac Alternating current.
IALA International Association of Lighthouse Authorities.
ICI Imperial Chemical Industries plc (UK).
IDC or Idc Direct current.
IDMT Inverse definite minimum time.
IEC International Electrotechnical Commission.
IEE The Institution of Electrical Engineers of UK.
IEEE The Institute of Electronic and Electrical Engineers of USA.
I/O Input or output signals or quantity.
IMO International Maritime Organisation.
IMCS Integrated motor control system.
IMS Information management system.
inst. Instantaneous quantity.
int. Intermittent quantity.
IP Institute of Petroleum (UK) and its publications.
IP Ingress protection code, see IEC60529.
IR Insulation resistance.
IS Intrinsically safe signal, circuit or equipment.
Is/In or IS/IN Ratio of starting current to running current.
ISO International Standards Organisation.

J Energy in joules or newton-metres.
J Current density, amps/mm2.

kA Kilo-amperes.
KEMA Short circuit testing authority in The Netherlands.
kg Kilogram.
km Length in kilometres.
kpm Kilometres per hour.
kV or Ku Kilo-volts.
kVA Kilo-volt-amperes.
kVAr Reactive kilo-volt-amperes.
kW Kilowatts.

L Electrical inductance in henries.
L Line or local control operation.
LAN Local area network.
lbs Weight of a substance in pounds.
LDS Low density foam.
LED Light emitting diode.
LEL Lower explosive limit.
LF Low frequency.
LHS Left-hand side.
Lloyds Lloyds Register of Shipping (UK).
LMS Load management system.
LNG Liquefied natural gas.
loc or (L) Local operation.
LPG Liquefied petroleum gas.
LSDS or LSS Load shedding system.
LSF Low smoke and fumes, applied to cables and wires.
LSLH Low smoke low halogen.
LSRS or LSR Load sharing system.
LV Low voltage, 51 to 599 volts.
L1, L2, L3, N Notation for line and neutral voltages and currents.
LUX Level of illumination.

m Length or dimension in metres, or month.
mA Current in milli-amperes.
man or (M) Manual operation.
mbar Milli-bar.
MB High-pressure mercury, without phosphor coating.
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.
MCB Miniature circuit breaker.
MCC Motor control centre.
MCCB Moulded case circuit breaker.
MCF Switch-start lamp, also used for tubular fluorescent lamps in general.
MCFE Starterless lamp, coated with silicone.
MCFA Starterless lamp, with earth strip, mainly used in cold environments.
MCR Maximum continuous rating.
MCU Motor control unit.
MESG Maximum experimental safe gap.
Mho Unit of electrical admittance.
MIC Minimum ignition current.
MICC Mineral insulated calander cable.
MIMIC Mimic display panel.
mm Length or dimension in millimetres.
MMF or mmf Magneto-motive force.
MMI Man–machine interface.
MMSCF Million standard cubic feet of a gas.
Mole % Molecular weight in %.
MSW Module steelwork.
MT Mica glass tape.
MTBF Mean time between failures.
MTTR Mean time to repair.
MV Medium voltage.
mV Voltage in millivolts.
MVA Mega-volt-amperes.
MVAr Reactive mega-volt-amperes.
MW Megawatts.

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.
NACE National Association of Corrosion Engineers (USA).
NBR Nitrile butadiene rubber.
NC or N/C Normally closed switching device.
NDE Non-drive end of a shaft.
NEMA The National Electrical Manufacturer’s Association (USA).
NEC National Electric Code (USA).
NER Neutral earth resistor.
NFPA National Fire Protection Association (USA).
Ni Nickel metal.
NO or N/O Normally open switching device.
NOx Nitrogen based gas emissions.
NPT National pipe threads (USA).
NS Used to describe a type of variable speed AC motor
NTS Not to scale.

O Open, off or stop.
OC or O/C Overcurrent or open circuit.
OCB Oil circuit breaker.
OF or O/F Overfrequency.
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 or OHLine Overhead line.
Ohms Unit of electrical resistance or impedance.
OIM Offshore installation manager.
OL or O/L Overload.
ONAF Naturally circulated internal liquid, forced heat exchanging to external air.
ONAN Naturally circulated internal liquid, natural heat exchanging to external air.
OSHA Occupational Health and Safety Administration (USA).
OV or O/V Overvoltage.

P or W Active power, watts.
PA Public address system.
p or s Laplace operator in mathematics, for transfer functions.
PC Programmable controller or personal computer.
PAM Pulse or pole amplitude modulation.
PCC Point of common connection.
PB or Pb Lead metal.
PBWB Phosphor bronze wire braid.
PBCU or TCU Tinned copper.
P & ID Piping and instrument diagram.
PF or pf Power factor.
Ph or ph Phases of an electrical circuit.
pk or peak Peak value of an instantaneous quantity.
PLC Programmable logic controller.
PMS Power management system.
POL Polyethylene.
PTB Physilalish Technische Bundesanstalt.
PTP Polyethylene terephthalate.
PTFE Polytetra fluoro ethylene.
pu or p.u. Per unit.
PVC Polyvinyl chloride.
PVDF Polyvinylidene fluoride.
PWM Pulse width modulation.

Q Reactive power, volt-amperes-reactive.
QA Quality assurance.
QC Quality control.

R or r Electrical resistance.
Rad or rad Angular displacement in radians.
RAM Random access memory.
RCU Remote control unit.
Ref. or REF. Reference.
rem or (R) Remote operation.
RHS Right-hand side.
RMS, rms Root mean square.
RMU Ring main unit.
ROM Read only memory.
RTD Resistance temperature detector.
RTU Remote transmitter unit.
Rx Receiver.

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.
SBM Single buoy mooring.
SC or S/C Short circuit.
SCADA Supervisory control and data acquisition system.
SCF Standard cubic feet of a gas.
SDR Single discipline review.
SECT Skin effect current trace heating.
SELV Safety extra-low voltage.
SF6 Sulphur hexafluoride.
SI Syst`eme Internationale d’Unit´es
SLI Double-ended, linear arc tube.
SOLAS Safety of life at sea, a document relating to marine practice.
SON Diffused ellipsoidal outer bulb, single-ended lamp.
SON-T Clear tubular outer bulb, single-ended lamp.
SON-TD or – L Clear tubular outer bulb, double-ended lamp.
SON-R SON lamp, with internal reflector.
SOL CU Solid copper.
SOX U-shaped arc tube, single-ended lamp.
Sox Sulphur based gas emissions.
SP Single phase.
sq Square, e.g. sq mm is square millimetres.
sq2 Square root of 2.0 = 1.414214
sq3 Square root of 3.0 = 1.732051
SSR Synchronisation check protection relay.
STG Steam turbine generator.
STR CU Stranded copper.
SWA Steel wire armour.
SWBD Switchboard.
SWGR Switchgear.
SYNC or Sync Synchronising.

T or t Time, usually in seconds.
Td Time constant in seconds for the quantity ‘d’.
TDRM Time delayed restart relay.
TEFC Totally enclosed fan cooled.
temp. Temperature.
TESFC Totally enclosed separate fan cooled, fan attached to an auxiliary motor shaft.
TG Turbo-generator, gas or steam.
THF Telephone harmonic factor.
TOP Gas-turbine operating temperature (hot-end blade temperature).
TM Technical measurement system of units.
TCP Gas-turbine control panel.
TLX Cold starting tubular fluorescent lamp, with single-pin caps.
TPN Three-phase and neutral power supply.
TPPL Total plant peak load.
TPRL Total plant running load.
Tran. or Tx Transformer.
Tx Transmitter.

U Voltage, also used for energy.
UC or U/C Undercurrent.
UCP Unit control panel.
UEL Upper explosive limit.
UF or U/F Underfrequency.
UHF Ultra high frequency.
UI or U/I Undercurrent.
UL or U/L Underload.
UL Underwriters Laboratory (USA).
UNO Unless noted otherwise.
UPS Uninterruptible power supply unit.
UV or U/V Undervoltage.

V or U Voltage or volts.
VA Volt-amperes.
VAC or Vac Alternating voltage.
VAr or Var Reactive volt-amperes.
VDC or Vdc Direct voltage.
VDE Verband Deutscher Electrechniker (Germany).
VDI Verein Deutscher Ingenieure (Germany).
VDU Visual display unit.
VHF Very high frequency.
VSI Voltage source inverter.
VSD or VSDS Variable speed drive systems.
V.T. or VT Voltage transformer.
v/v Comparison by volume, per-unit.

W or P Active power, watts.
w or ω Frequency in radians per second.
wdg. Winding of a machine or transformer.
WHRU Waste heat recovery unit.

X or x Electrical reactance.
XLPA Cross-linked polyalkene.
XLPE Cross-linked polyethylene.

Y or y Electrical admittance.
y Year.

Z or z Electrical impedance.
ZH Zero halogen, as used for cables.

1P or 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.

My photo as a illustration

About the Author

- Radoje - Rade Jankovic Electrician, Electrical Technician, Electrical Engineer, PhD, Ecologist, Environmentalist, Designer, Educator, Investigator... Today PROFESSIONAL TECHNICAL WRITER AND DOCUMENTATOR Massive practical experience in almost all fields of electrical engineering over 40 years. My International education group in Facebook: EEEW - ELECTRICAL & ELECTRONIC EDUCATION WORLD where published more than 8000 small or bigger articles, lessons, technical advice, projects, technical calculations, test questions with and without answers, illustrated test questions with and without answers; all my original works and few thousands of may original photos from practice, drawings, circuit diagrams, environmental lessons and examples from everyday practice etc., etc.

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Abbreviations Commonly used in Electrical Documents