Industrial Engineer · phase 10 of 16 · noun

Slip

Difference between an induction motor's synchronous speed and actual rotor speed.

The Explain card

Plain English: Slip is the difference between synchronous speed and the speed the rotor actually turns. An induction motor needs some slip, because the rotor only makes torque when the field is moving past it.
Example: A motor with a synchronous speed of 1800 rpm turns 1760 unloaded and 1740 at full load. That 60 rpm at full load is about three percent slip.
Why it matters: Slip grows with load, so shaft speed drifts down as the machine works harder unless the drive compensates. A motor with far too much slip is overloaded, under voltaged or has a rotor problem, and slip is how you tell.
Hook: The rotor is always chasing the field and never catching it.

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

In a sentence

During commissioning, the technician verifies that slip remains within the motor manufacturer's full-load range before accepting the drive setup.

How it is built

Where it came from

Origin: Middle English slippen, probably from Middle Dutch slippen
Entered the language: 15th century
What changed: The sense developed from sliding or losing one's footing to relative motion, then entered induction-motor terminology in the late 19th century.

How it is spelled

Pattern: The short i appears in a closed syllable.
Pattern: The final consonant doubles before vowel-led suffixes, as in slipped and slipping.

Spelled like

Broken into chunks

What it sits beside

Same subject

Same shape

induction-motor operating quantities

Phase 10: VFD Electrical and Motor Fundamentals

The physics under the parameters: slip, torque, flux, and the relationship between frequency and voltage that every drive is really controlling.