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Electrical Abbreviations

The list of abbreviations used in a set of engineering drawings varies from office to office. Be sure to check the front section of the drawing set for the abbreviations used within.

Ω  Ohm
Φ  Phase
A  Amperes
AC Alternating Current
A/C Air Conditioning
AHU Air Handling Unit
AIC Ampere Interrupting Capacity
AL Aluminum
ATS Automatic Transfer Switch
ATC Automatic Temperature Control
AWG American Wire Gauge
BTU British Thermal Units
C Conduit
CATV Community Antennae Television
CB Critical Branch
C/B Circuit Breaker
CBM Certified Ballast Manufacturer
CCTV Closed Circuit Television
CD Candela
CKT Circuit
CLF Current Limiting Fuse
CPT Control Power Transformer
CT Current Transformer
CU Copper
dB Decibel
DC Direct Current
DIA Diameter
EB Equipment Branch
EC Electrical Code or Electrical Contractor
EF Exhaust Fan
ELEV Elevator
EM Emergency
EMT Electrical Metallic Tubing
EP Emergency Power
EPO Emergency Power Off (Button or Switch)
EWC Electric Water Cooler
F Fuse
FA Fire Alarm
FAA Fire Alarm Annunciator
FLA Full Load Amperes
FMC Flexible Metal Conduit
G Ground
GFCI, GFI Ground Fault Circuit Interrupter
GND Ground
GRMC Galvanized Rigid Metal Conduit
HOA Hand-Off-Automatic Switch
HVAC Heating, Ventilation, Air Conditioning
IEEE Institute of Electrical and Electronic Engineers
IG Isolated Ground
IMC Intermediate Metal Conduit
INT Interlock
KCMIL Thousand Circular Mils
KVA Kilovolt-Amperes
KVAR Kilovolt-Amperes Reactive
LFMC Liquid Tight Flexible Metal Conduit
LTG Lighting
LRA Lock Rotor Amps
MC Metal Clad Cable
MCB Main Circuit Breaker
MCC Motor Control Center
MCP Motor Circuit Protection
MI Mineral Insulated
MLO Main Lugs Only
NC Normally Closed
NEC National Electrical Code
NEMA National Electrical Manufacturers Association
NFPA National Fire Protection Association
NL Night Light
NO Normally Open or Number
P Pole
PB Push Button or Panic Button or Pull Box
PNL Panel
PWR Power
PT Potential Transformer
QTY Quantity
REQ Required
RMC Rigid Metal Conduit
RMS Root Mean Squared
RNC Rigid Non-Metallic Conduit
RTS Remote Test Station
RTU Roof Top Unit
SP Spare
ST Shunt Trip
SW Switch
SYM Symmetrical
TEL Telephone
TMCB Thermal Magnetic Circuit Breaker
UG Under Ground
UL Underwriters Laboratory
V Volt
VA Volt-Ampere
VT Voltage Transformer
W Watt or Wire
WH Water Heater
WP Weather Proof
XFMR Transformer