Sparky's Journal

📅 May 24, 2026

Another day, another page in the journal. If you’ve been in the trade for more than a week, you already know that the electrical world runs on shortcuts — and I’m not just talking about parallel paths. I’m talking about abbreviations.

These little codes show up everywhere: on prints, in the NEC, on equipment labels, in voltage drop calculations, and especially on your journeyman or master exam. If you don’t speak the language, you’re going to struggle — both in the field and on test day.

Here’s my go-to list of the electrical abbreviations every sparky should know cold.

Basic Electrical Units

Abbreviation

Meaning

What It Actually Means in the Field

V

Volt

Electrical pressure / potential difference

A

Ampere (Amp)

Amount of current flowing

Ω

Ohm

Resistance to current flow

W

Watt

Power (Volts × Amps)

VA

Volt-Ampere

Apparent power (especially important for transformers & UPS)

kW

Kilowatt

1,000 Watts

kVA

Kilovolt-Ampere

1,000 VA

Hz

Hertz

Frequency (60 Hz in North America)

mA

Milliamp

1/1000 of an amp (GFCI trip levels)

kA

Kiloampere

Fault current ratings (AIC)

Power Systems & Current Types

• AC — Alternating Current

• DC — Direct Current

• VAC — Volts Alternating Current

• VDC — Volts Direct Current

• PH — Phase (Single-phase / Three-phase)

• 1Ø / 3Ø — Single-phase / Three-phase

Safety Devices & Protection

• NEC — National Electrical Code (NFPA 70)

• GFCI — Ground Fault Circuit Interrupter

• AFCI — Arc Fault Circuit Interrupter

• GFPE — Ground Fault Protection of Equipment

• OCPD — Overcurrent Protective Device

• AIC — Amps Interrupting Capacity

• SCC — Short Circuit Current

• CB — Circuit Breaker

• MCCB — Molded Case Circuit Breaker

Wiring & Raceways

• AWG — American Wire Gauge

• kcmil — Thousand circular mils (used for large conductors)

• THHN/THWN — Common insulation types

• EMT — Electrical Metallic Tubing

• RMC — Rigid Metal Conduit

• PVC — Polyvinyl Chloride (Schedule 40/80)

• ENT — Electrical Nonmetallic Tubing

• MC — Metal-Clad Cable

• NM — Nonmetallic-Sheathed Cable (Romex)

• UF — Underground Feeder

Common Equipment & System Terms

• Panelboard → Often just called Panel

• MDB — Main Distribution Board

• LP — Lighting Panel

• ATS — Automatic Transfer Switch

• VFD — Variable Frequency Drive

• UPS — Uninterruptible Power Supply

• Transformer → XFMR

• Ground → GND or G

• Equipment Grounding Conductor → EGC

Other NEC Favorites You’ll See on Exams

• AHJ — Authority Having Jurisdiction

• FPN — Fine Print Note (in the NEC)

• Article 100 — Definitions (know this chapter!)

• Branch Circuit — The circuit after the last OCPD

• Feeder — Circuit between service equipment and branch circuit panels

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