ECN Glossary:
Reference for frequently-used terms and acronyms in threaded messages at ECN by Members.

*Note: Many of these definitions are contributed by Members. This list may be updated periodically, to include newer or additional terms.


Active Conductor: Conductor(s) of a Power System, which carry load Currents during normal operation.

AFAIK: As Far As I Know.

AHJ: Authority Having Jurisdiction (commonly the local building officials).

AC: (1): Armored Cable "BX". (2): Alternating Current. (3): Air Conditioner/ing.

ATS: Automatic Transfer Switch.

AMP: (1): Amperes. (2): Amplifier.

AMPROBE: Clamp-On (Current Transformer Type) Ammeter.

A: Phase / Line in the "A" position.

AFCI: Arc-Fault Circuit Interrupter.

AIC: Amperes Inrush Capacity.

AIR: Amperes Interrupting Rating.

AFC: Available Fault Current.

AF: "Amp Frame". Maximum rating category for a Circuit Breaker's frame size.

AT: (1): "Amp Trip" - refers to the actual trip setting for a given Breaker's "AF". (2): "Advanced Technology" - IBM's reference to the IBM PC with an 80286 CPU.

Advance Ballast: Ballast made by Advance Transformer, Inc.



BX: Armored Cable.

BTW: By The Way.

B: Phase / Line in the "B" position.

Bender: Conduit Benders-Hand or Hydraulic types.

BAS: Building Automation System - also see EMS.

Breaker: Circuit Breaker.

Ballast: Current limiting device used typically with Discharge Lamps.

Bond(ing): To physically connect two or more separate items together, typically via a conductor or screw.



CT: Current Transformer.

CT Can: Enclosure for CTs.

Can: (1): Enclosure. (2): Recessed Lighting Fixture.

Common: Common Conductor - typically the System's Grounded Conductor.

CB: Circuit Breaker.

C: Phase / Line in the "C" position.

CKT: Circuit.

C.: Conduit

CEC: (1): California Electrical Code. (2): Canadian Electrical Code. (3): California Energy Commission.

CO: Central Office (Telephone Utility).

C.O.: Conduit Only

"C": C type Conduit Body.

CMP: Code Making Panel.

CAT-(3,5,etc.): Category rating of Data cables, per EIA/TIA.

CAP: Capacitor.

CATV: Community Antenna Television.



Disco: Disconnect / Disconnect Switch.

DC: Direct Current.

DP: (1): Distribution Panel. (2): Double-Pole.

DF: Distribution Frame.

D'OH!: To mess up or forget. Also see: Homer Simpson.

DMM: Digital Multimeter.

DVM: Digital Voltage Meter.

Delta: Triangle, or Triangle configuration.

Duplex: (1): Receptacle with two usable outlet points. (2): Service Entrance Feeder Cable with two Conductors.

Device: Receptacle or Switch.

Daisy Chain(ed)/(ing): To run one item through another one - such as to connect a "Plug-Strip" to another "Plug-Strip". Also the method of connections for MAUs on a Token Ring Network, or connections for a "Ring" topology Ethernet Network.



EXO: Externally Operated - as in switches, disconnect switches.

EGC: Equipment Grounding Conductor.

ESD: Electro-Static Discharge.

EMF: (1): Electro-Motive Force or "Voltage". (2): Electro-Magnetic Field.

EMR: Electro-Magnetic Radiation (Electrical Power, Light, etc.).

EC: Electrical Contractor

ECN: Electrical Contractor Network.

EMT: Electrical Metallic Tubing.

EMS: (1): Energy Management System - see also BAS. (2): Emergency Medical Staff (need clarification to this)

ENT: Electrical Non-Metallic Tubing - also see "Smurf Tube"

E: Voltage. Root term = "Electromotive Force"

Electrical Engineer: Term for person(s) whom design Electrical Equipment &/or Systems. This term applies to all Electrical Engineers, not just those involved with Power System Engineering and Design.

EE: Electrical Engineer.

EIT: Engineer-In-Training (1st part of becoming a licensed PE).

E=IR: Basic Ohms Law.

E-Mail: Electronic Mail - either Local via LAN, or "End-User" via Internet.

End-User: Final user of any Equipment, which the Equipment is intended to be built for and used by. If you are reading this, you are the "End-User" of the Computer you are using (unless the Computer is someone else's - then that Person / Corporation is the "End-User").

Emulate: To "Act-Like" or "Behave-Like" something else. i.e.: IBM 3270 Emulation.



Fault: Accidental contact of live circuit conductors (AKA "Short").

FYI: Acronym for: For Your Information.

FWIW: Acronym for: For What It's Worth.

FPE: Federal Pacific Electric.

Fault Current Calcs: Calculations to find level of Fault Current available for a given System, or at certain points on a given System.

Full Boat: Multiwire Circuitry - per 3Ø 4W Wye Systems; 3 Ungrounded Conductors + 1 Common Grounded Conductor.

Fry / Fried: Burn up. To let the smoke out of something.

Flame/s: To reply with anger, in regards to a certain posted message.

FPN: Fine Print Notes.

Flex: Flexible Metallic Conduit - see also Greenfield.

FLA: Full Load Amperes.

Four Wire System: Power System which uses 4 active circuit conductors.

FS: Fusible Switch.

FTP: File Transport Protocol.

FIFO: First-In-First-Out.

FILO: First-In-Last-Out.



Google: (1): Very cool search engine. (2): A very large number! (a "One" followed by one hundred "Zeros").

GEC: Grounding Electrode Conductor.

GES: Grounding Electrode System.

GC: (1): General Contractor. (2): Grounded Conductor.

GFI: Ground Fault Interrupter - see also GFCI.

GFCI: Ground Fault Circuit Interrupter.

GFPE: Ground Fault Protection for Equipment.

GRC: Galvanized Rigid Conduit - see also RMC.

GMT: Greenwich Mean Time.

GIF: Graphical Image file Format. Format typically used for drawings to post in Threads or messages. See also: JPG.
(Pronounced: "Jiff").

Greenfield: Slang term for Flexible Metallic Conduit.

Genny: Generator.

G Rod: Ground Rod.



HVAC: Heating, Ventilation and Air Conditioning.

High Voltage: (1): >35KV. (2): If two systems are used, the one with higher voltage.

HDPE: High Density Polyethylene.

Homer Simpson: Cartoon character on "The Simpsons" with tagline of "D'OH!". Husband of Marge Simpson, Father of Bart, Lisa and Maggie Simpson. See also: D'OH!

H.O.A.: Hand - Off - Automatic.

Homerun: Circuitry / Raceway from first outlet or J-box, to Panelboard.

H1 (2,3, etc.): Terminal Points normally referencing the Primary side of a Transformer.

H.I.D. (or HID): High Intensity Discharge lighting.



Info: Information.

I.T.: Information Technology.

IEEE: Institute of Electrical and Electronic Engineers
(Pronounced "Eye-Triple-E").

IMO: In My Opinion.

IMHO: In My Honest / Humble Opinion.

IMC: Intermediate Metallic Conduit.

IC: Integrated Circuit.

ITL: Independent Testing Lab.

I: Amperes. Root term = "Intensity"

I=ER: Basic Ohms Law (again).

Impedance: Total Opposition to an Alternating Current.

Image: Picture or drawing, posted in a thread or message. See also GIF, JPG



J-Box: Junction Box.

JPG: Joint Photo Experts Group. Refers to a type of graphical image - typically for a photographical type. See also: GIF.
(Pronounced: "Jay-Peg").



Kilo: Unit for "1000".

KW: Kilo Watt/s.

KVA: Kilo Volt-Amperes.

KVAR: Kilo Volt-Amperes Reactive.

Klien: Popular Tool Company.

Kliens: Electricians' / Linemans' Pliers.

K&T: knob and Tube.



Load: (1): Equipment connected to a circuit. (2): Current, in Amperes. (3): Side of a device which Current is designed to flow away from.

Line: (1): System Circuit Conductor, normally Ungrounded. (2): side of a device which Current is designed to flow towards or into.

LOL: Laughing Out Loud.

LAN: Local Area Network.

L-L: Line-to-Line.

L-L-L: Line-to-Line-to-Line (3).

L-C: Line-to-Common.

L-N: Line-to-Neutral.

L-G: Line-to-Ground.

LMNO: 12th, 13th, 14th, and 15th letters of the Modern Roman Alphabet, typically spoken out as "Elle-Emme-Enne-Ohh" (ref. "Metric Dictionary").

LIFO: Last-In-First-Out.

LCL: Long-Continuous-Load(s).



MDP: Main Distribution Panel.

MCCB: Molded Case Circuit Breaker.

MCC: Motor Control Center.

MATV: Master Antenna Television.

MCA: Minimum Circuit Amperes.

MTD. Mounted.

MIN.: Minimum.

MAX.: Maximum.

Mounting Ears (or just "Ears"): Removable Circular extensions located on a device's Mounting Strap/Yoke.



NEC: National Electrical Code.

NEUTRAL: On Grounded AC Systems, the Grounded System Conductor.

Noodle: Grounded Common Conductor of a Multiwire Circuit / System. (See "Neutral")

NFPA: National Fire Protection Association.

NFPA 70: The NEC.

Non-Contact Tester: Tester used to determine if a circuit might be energized, without making a physical contact of probes to any circuit conductor or bus bar.

N-G: (1): Neutral and Ground. (2): Neutral to Ground.

N&G: Same as "N-G".



OCPD: Over Current Protection Device.

O.T.: Off Topic

OTOH: Acronym for: On The Other Hand.

OEM: Original Equipment Manufacturer.



PoCo: Power Company.

POTS: Plain Old Telephone System.

Panel: Enclosure for given System's equipment.

PVC: Poly Vinyl Chloride. Also is slang term for Plastic Conduit made of PVC (see RNMC).

PM (or P.M.): (1) Project Manager. (2): Private Message. (3): Post Meridian.

POST: (1): To "Send" or "Upload" a message or item to a Thread. (2): After. (3): A "Pole-Like" structure - typically made of Wood. (4): Power-On-Self-Test.

Pic(s): Picture(s).

PIX: Same as "Pics".

Plug-Strip: A Factory Made multi-receptacle strip device, which derives Electrical Power from a receptacle device of a fixed premisis wiring system, via a cord "Whip". These devices are "Intended" to be for Temporary Usage. These items are typically used with Computer setups, to connect many Peripheral devices for Electrical Power, and commonly integrate TVSS devices within the Assemblage.

Panel Schedule (P. Sch./ Pan. Sch.): Panel capacity Schedule. Panel Schedules are A Database used to calculate the capacity of a given Panelboard, by listing the designed circuits load (in Volt-Amps), the equipment driven by a given circuit, the Voltage of the System, and an LCL factor.
Panel Schedules are typically found on the "E" Sheets of Plansets.

Panel Directory (P. Dir. / Pan. Dir.): Panel mounted Directory. A Database listing the circuitry of connected equipment, per the circuit numbers of the Panelboard, which is mounted on the inside portion of the Panelboard's Door.



Quote: Quote another part of a message.

Q: Question.

QUAD: (1): Receptacle made up of two-Duplex Receptacles. (2): Service Entrance Cable with Four Conductors. (3): Four (items/points/etc.).



QUADRI-VOLT: An H.I.D. Ballast with four separate system voltage input leads. Manufactured by Advance Transformer, Inc.

QO: Type of Square D Circuit Breaker.

QOB: "Bolt-On" QO Breaker.



RMS: Root-Mean-Square. AKA Effective Value.

RMC: Rigid Metallic Conduit.

RNMC / RNC: Rigid Non-metallic Conduit.

Romex: Type NM cable.

R: Resistance.

R=EI: Basic Ohms Law (again).

Rockers: "Sheet Rockers". Installers of "Drywall" - Gypsum Wallboard.

Recept. (REC.): Receptacle.



Sealtite: Liquid Tight Conduit.

SCA: Short Circuit Amperes.

SDS: Separately Derived System.

Star Point: Common connecting point of windings or conductors.

Snail-Mail: Sending messages and letters via physical methods - as in US Mail Service.
Termed because it's not as fast as "E-Mail".

SHEETROCK: Gypsum Wallboard / "Drywall".

SHEETROCKER(s): Installers of Sheetrock.

(SP???): Unsure of correct spelling used for previous word(s).

SPAM: Annoying unsolicited E-Mail advertisements.

SPAMBOT: E-Mail Automailer, which sends out SPAM. (E-Mail ROBOT is term for Mail System).

SPYWARE: An applet or such which tracks a user's searches on the Internet, then reports back to an Advertiser's Harvester (or much worse!). Spyware is "Semi-Virial" code.



Trans.: Transformer.

TIA: Acronym for: Thanks In Advance.

Three-Wire System: Power system that uses 3 active circuit conductors.

Temp.: Temporary.

Thread: A posted topic, which has at least one reply.

Triplex: Service Entrance Cable with three conductors.

Tag(s): HTML or UBB code lines, used to enhance a message. Tags include those used to make text bold or italicized, along with adding images or Hyperlinks.
***NOTE: Sometimes a user will insert "Intended Non-Functioning Tags", which are meant to be seen as they are, for the intentions of adding humor or adding an enhancement which is not available.
Typical INF Tags are:
<"XXX"> <"/XXX">
["XXX"] ["/XXX"]
for a statement;
for an underlined word.



Underground: Installed under grade level, or under concrete/asphalt.

UL: Underwriters' Laboratories.

UC: Ungrounded Conductor.

UTP: Unsheilded Twisted Pair cable.

USB: Universal Serial Bus.

UPS: Uninterruptable Power Supply.



Ver.: Verify.

V: Volt/s.

VA: Volt-Amps.

VAR: Volt-Amps Reactive.



WP: Weather Proof.

W: Watt/s.

Wye: Star configuration.

Wiggy: Solenoid type Voltage Tester, for use on AC or DC Circuits of 100-600 Volts.

Whip: Cable or Flexible Conduit segment used to connect a piece of Equipment.

WAN: Wide-Area-Network.

W/S: Work Station.



X: Reactance.

XL: Inductive Reactance.

XC: Capacitive Reactance.

Xformer / Xfmr: Transformer.

X0 / X1 (2,3, etc.): Typically refers to the Secondary Termination Points of a Transformer.

X-Axis: Line / Line Segment on the Horizontal Plane.



Y: Wye, or Star configuration.

Y-Axis: Line / Line Segment on the Vertical Plane.



Z: Impedance.


The following items are directly pasted from Members' input:

Topic: ECN Glossary

* Disco: disconnect.
* PoCo: Power Company.
* GC: general contractor.
* EC: electrical contractor.
* Rx: Romex.
* EGC: equipment grounding conductor.
* GEC: grounding electrode conductor.
* AHJ: (from the NEC) Authority Having Jurisdiction.
* K&T: Knob and Tube (art 394).
* BX: Armored cable.
* Ducky: (art 368..)Bussways.
* OCP: overcurrent protection.
* OCPD: Overcurrent Protection Device.
* LD's: liquidated damages.
* CT can: current transformer enclosure used by the PoCo for metering.
* PT can: Potential Transformer enclosure used by PoCo for metering.
* 1900 box: some people call it a 4s box or a 4" square box 333 box or a switch box.
* Rabbit: wire trimmings (taken to salvage and sold).
* Rabbit gun: large wire cutters (some may be ratcheting type).
* Noodle: neutral wire.
* Dikes: Diagonal Cutters.
* 'Lectrician's Hammer: Lineman's pliers.
* 'Lectrician's Chisel: Large Flat Screwdriver.
* Can: Meterbase, enclosure or box, usually metallic.
* Pig: Garbage Disposal.
* CB: Circuit Breaker.
* DMM: Digital Multimeter.
* ECN: The Electrical Contractor Network (here).
* X-former: Transformer.
* Pie axe or axe: cable shears.
* Trailer: extension cord.
* Baloney: larger type W or G flexible supply cord.
* Dogs: channelock pliers.
* Ship auger: wood boring drill bit.
* Kleins: Original 19th-century lineman's pliers.
* Edison: just about anything electrical.
* Westinghoused: executed with alternating current.
* Minerallac: (1) bolt-through conduit of tubing clamp;
(2) non-contact neon-and-mirror circuit tester for industrial 2.4-4.8kV.
* Indenters: 1950's system of ½-1 inch "crimped" EMT connector/coupling of arguable ground continuity.
* GRC/RMC: Galvanized Rigid Conduit/Rigid Metal Conduit.
* Glass: fiber-optic cable.
* Sherardized: trade term for conduit anodizing.
* T/TW: thermoplastic/vinyl wire insulation.
* Deion: early principal arc-interruption/extinction method for AC circuit breakers.
* 4 Wire Delta terms for Bø (occasionally Cø) of higher voltage to 'neutral'/ground:
Stinger Leg; Red Leg; Orange Leg; Purple Leg; Power Leg; Wild Leg; Bastard Leg; High Leg.
* K.O.: Knock Out.
* U/G: Underground.
* W/P: Weatherproof - See also: W.P..
* W.P.: Wall Pack.
* XFMR: X-former.
* MLO: Main Lug(s) Only panel / Bus.
* MCB: Main Circuit Breaker.
* Roach Coach: Job Site Catering Vehicle.
* 5sq box: 4 11/16 inch box.
* Bow Ties: conduit support metal brace attached to box.
* Lopers: long handled cable cutters.
* Lube: Pulling Lubricant.
* Wire Soap: Same as "Lube".
* Batwings: k8's k12's (Caddy Clips).
* SDP: Secondary Distribution Panel.
* Round House: Black/Red/Blue/White/Green.
* Full Boat: Black/Red/Blue/White/Green.
* TSP: Twisted Shielded Pair.
* Cub: Apprentice.
* Jake: Flex Connector.
* GC: grounded conductor.
* GE: grounding electrode.
* Goof Plugs (AKA Goof fillers, Oopsies): K.O. Seals.
* K.O. Seals: KnockOut Seals.
* Reeler: welded metal stand you feed 500' wire spools from when pulling wire - they look like an upside down "U" with 4 crossarms.
* Roller: 4' fold up or 6' break down scaffold with wheels on the bottom.
* Can (alt.): a recessed lighiting fixture.
* Tell-tale: non-contact voltage detector, indicates by visual, audio, or both.
* Stick: Conduit, either singular or plural.

Some "official" British terminology:

* CPC = Circuit Protective Conductor (=EGC).
* ECC = Earth Continuity Conductor (obsolete).
* ELCB = Earth-Leakage Circuit Breaker.
* MCB = Miniature Circuit Breaker.
* PME = Protective Multiple Earthing.
* RCCB = Residual Current Circuit Breaker.
* RCD = Residual Current Device (=RCCB=GFI).
* SWA = Steel Wire Armoured (cable).
* TRS = Tough Rubber Sheath (obsolete).
* Consumer unit = distribution panel with main switch.
* Earth/Earthing/Earthed = ground/grounding/grounded.
* Isolator = disconnect.
* Plate switch = combined switch/cover plate.
* Plug top = cord cap.
* Socket outlet = receptacle.
* Twin socket = duplex receptacle.

Some colloquial usage:

* Earth trip = ELCB or RCCB/RCD.
* Live wire = phase conductor (equiv. to "hot").
* T&E = "twin & earth", normal 2-cond. w/ground cable.
* Builder's screwdriver = big hammer!


Posted 01.18.2004 by Scott35.

Last edited by Scott35; 08/24/10 07:56 PM. Reason: Fixed "Phi" symbols

Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!