Industrial Engineer · phase 16 of 16 · noun

AC Drive

Common industry name for an electronic drive that controls an AC motor.

The Explain card

Plain English: AC drive is the plain industry name for an electronic controller that runs an AC motor at variable speed. It is what a VFD is, said without the acronym.
Example: A catalog lists AC drives from a quarter horsepower to several thousand. Every one of them rectifies, stores on a bus, and inverts.
Why it matters: DC drives still exist for old DC motors, and servo drives control AC servo motors with position feedback, so AC drive is the name that separates the common induction motor controller from its relatives. When someone says drive with no qualifier in a plant, this is what they mean.
Hook: A VFD, in words.

How the word is built, where it came from, and what it sits beside in memory.

In a sentence

The technician connected the PLC speed reference to the AC Drive analog input during commissioning.

Why these words

AC initialism of alternating current identifies the electrical current associated with the equipment
Drive Old English drīfan, to propel or urge onward names the equipment class within the phrase

Where it came from

Origin: English technical compound formed from the initialism AC and the machinery noun drive
Entered the language: 20th century
What changed: Drive developed from the verb meaning to propel into a noun for machinery that transmits or regulates motion, then joined AC in electrical engineering usage.

How it is spelled

Pattern: AC is conventionally written as an uppercase initialism without periods.
Pattern: The final silent e in drive marks the long i sound.

Spelled like

Broken into chunks

What it sits beside

Same subject

Same shape

industrial drive terms

electrical initialisms

Phase 16: VFD Related Drive Terms

The drive family's wider vocabulary, from soft starters and servo drives to the regenerative units people also call a drive.