| Abbrev. | Definition |
| A
| amperes |
| ac
| alternating current |
| AMPAC
| ampacity |
| ANSI
| American National Standards Institute |
| ASHRAE
| American Society of Heating, Refrigeration & Air Conditioning Engineers |
| BTU
| British Thermal Unit |
| C
| Celsius |
| °C
| degrees Celsius (centigrade) |
| CB
| circuit breaker |
| CT
| current transformer |
| DC
| direct current |
| DE
| dual element |
| EEI
| Edison Electric Institute |
| °F
| degrees Fahrenheit |
| fc
| footcandles |
| hp
| horsepower |
| Hz
| Hertz |
| IC
| interrupting capacity |
| IEEE
| The Institute of Electrical and Electronics Engineers, Inc. |
| kA
| kiloamperes |
| kHz
| kilohertz |
| kVA
| kilovolt-amperes |
| kvar
| kilovolt-amperes reactive (kilovar) |
| kW
| kilowatt |
| kWh
| kilowatt-hours |
| LVPCB
| low-voltage power circuit breakers |
| MCCB
| molded case circuit breakers |
| MCM
| thousand circular mils |
| MHz
| megahertz |
| m-g
| motor-generator |
| MVA
| megavolt-amperes |
| NEC
| National Electrical Code |
| NEMA
| National Electrical Manufacturers Association |
| OPEC
| Organization of Petroleum Exporting Countries |
| OSHA
| Occupational Safety and Health Act |
| p.f.
| power factor |
| rms
| root mean square |
| rpm
| revolutions per minute |
| SCR
| silicon controlled rectifier |
| SE
| single element |
| sw
| circuit breaker used as switch |
| TOD
| time-of-day |
| UL
| Underwriters' Laboratories |
| V
| volt |
| VA
| volt amperes |
| W
| watts |
| X
| reactance |
| X/R
| reactance to resistance ratio |
| Y
| wye system |
| Z
| impedance |
