kJ | kilojoule | NPSC | National Pipe, | SPST | |
km | kilometer | NPT | National Standard taper pipe | spec | specification |
kOhm, kΩ |
| thread per general use | specs | specification(s) | |
kPa | kilopascal | NPTF | National Pipe, | sq. | square |
kph | kilometers per hour | NR | not required, normal relay | sq. cm | square centimeter |
kV | kilovolt | ns | nanosecond | sq. in. | square inch |
kVA | kilovolt ampere | OC | overcrank | SMS | short message service |
kVAR | kilovolt ampere reactive | OD | outside diameter | SS | stainless steel |
kW | kilowatt | OEM | original equipment manufacturer | std. | standard |
kWh | OF | overfrequency | stl. | steel | |
kWm | kilowatt mechanical | opt. | option, optional | tach. | tachometer |
kWth | OS | oversize, overspeed | TB | terminal block | |
L | liter | OSHA | Occupational Safety and Health | TCP | transmission control protocol |
LAN | local area network |
| Administration | TD | time delay |
L x W x H | length by width by height | OV | overvoltage | TDC | top dead center |
lb. | pound, pounds | oz. | ounce | TDEC | time delay engine cooldown |
lbm/ft3 | pounds mass per cubic feet | p., pp. | page, pages | TDEN | time delay emergency to normal |
LCB | line circuit breaker | PC | personal computer | TDES | time delay engine start |
LCD | liquid crystal display | PCB | printed circuit board | TDNE | time delay normal to emergency |
LED | light emitting diode | pF pic | ofarad | TDOE | time delay off to emergency |
Lph | liters per hour | PF | power factor | TDON | time delay off to normal |
Lpm | liters per minute | ph., Ø | phase | temp. | temperature |
LOP | low oil pressure | PHC | Phillips head Crimptite (screw) | term. | terminal |
LP | liquefied petroleum | PHH | Phillips hex head (screw) | THD | total harmonic distortion |
LPG | liquefied petroleum gas | PHM | pan head machine (screw) | TIF | telephone influence factor |
LS | left side | PLC | programmable logic control | tol. | tolerance |
Lwa | sound power level, A weighted | PMG | permanent magnet generator | turbo. | turbocharger |
LWL | low water level | pot | potentiometer, potential | typ. | typical (same in multiple |
LWT | low water temperature | ppm | parts per million |
| locations) |
m | meter, milli (1/1000) | PROM | programmable | UF | underfrequency |
M | mega (106 when used with SI |
| memory | UHF | ultrahigh frequency |
m3 | units), male | psi | pounds per square inch | UIF | user interface |
cubic meter | psig | pounds per square inch gauge | UL | Underwriter’s Laboratories, Inc. | |
m3/hr. | cubic meters per hour | pt. | pint | UNC | unified coarse thread (was NC) |
m3/min. | cubic meters per minute | PTC | positive temperature coefficient | UNF | unified fine thread (was NF) |
mA | milliampere | PTO | power takeoff | univ. | universal |
man. | manual | PVC | polyvinyl chloride | URL | uniform resource locator (web |
max. | maximum | qt. | quart, quarts |
| address) |
MB | megabyte (220 bytes) | qty. | quantity | US | undersize, underspeed |
MCCB | R | replacement (emergency) power | UV | ultraviolet, undervoltage | |
MCM | one thousand circular mils |
| source | V | volt |
meggar | megohmmeter | rad. | radiator, radius | VAC | volts alternating current |
MHz | megahertz | RAM | random access memory | VAR | voltampere reactive |
mi. | mile | RBUS | VDC | volts direct current | |
mil | one |
| communications | VFD | vacuum fluorescent display |
min. | minimum, minute | RDO | relay driver output | VGA | video graphics adapter |
misc. | miscellaneous | ref. | reference | VHF | very high frequency |
MJ | megajoule | rem. | remote | W | watt |
mJ | millijoule | Res/Coml | Residential/Commercial | WCR | withstand and closing rating |
mm | millimeter | RFI | radio frequency interference | w/ | with |
mOhm, mΩ milliohm | RH | round head | WO | write only | |
MOhm, MΩ megohm | RHM | round head machine (screw) | w/o | without | |
MOV | metal oxide varistor | rly. | relay | wt. | weight |
MPa | megapascal | rms | root mean square | xfmr | transformer |
mpg | miles per gallon | rnd. | round |
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mph | miles per hour | RO | read only |
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MS | military standard | ROM | read only memory |
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ms | millisecond | rot. | rotate, rotating |
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m/sec. | meters per second | rpm | revolutions per minute |
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mtg. | mounting | RS | right side |
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MTU | RTDs | Resistance Temperature |
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MW | megawatt |
| Detectors |
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mW | milliwatt | RTU | remote terminal unit |
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μF | microfarad | RTV | room temperature vulcanization |
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N, norm. | normal (power source) | RW | read/write |
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NA | not available, not applicable | SAE | Society of Automotive Engineers |
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nat. gas | natural gas | scfm | standard cubic feet per minute |
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NBS | National Bureau of Standards | SCR | silicon controlled rectifier |
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NC | normally closed | s, sec. | second |
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NEC | National Electrical Code | SI | Systeme international d’unites, |
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NEMA | National Electrical |
| International System of Units |
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| Manufacturers Association | SI/EO | side in/end out |
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NFPA | National Fire Protection | sil. | silencer |
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| Association | SMTP | simple mail transfer protocol |
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Nm | newton meter | SN | serial number |
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NO | normally open | SNMP | simple network management |
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no., nos. | number, numbers |
| protocol |
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NPS | National Pipe, Straight | SPDT |
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56 Appendix |
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