Industrial Engineer · phase 10 of 16 · noun

Base Speed

Approximate motor speed at rated voltage and base frequency.

The Explain card

Plain English
Base speed is the shaft speed the motor reaches at base frequency and rated voltage, allowing for slip. It is the top of the constant torque range.
Example
A four pole motor with a 60 hertz base and 1750 on the plate has a base speed of 1750 rpm. Run it to 90 hertz on a drive and it turns about 2600 rpm, with less torque available.
Why it matters
Below base speed the motor can give full torque, above it the torque falls off. Whether a load can be run past base speed depends on whether it needs torque up there, and on whether the motor and the driven machine are rated to spin that fast.
Hook
The speed at which the motor runs out of voltage.

Word knowledge

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

In a sentence

During VFD commissioning, the technician checks that the commanded speed reaches Base Speed before enabling field weakening.

Why these words
  • base Greek basis, step or foundation, through Latin and Old French marks the reference point used for comparison
  • speed Old English sped, success or advancement names the measured motion being referenced
Where it came from
Origin
English engineering compound formed from base and speed
Entered the language
20th century
What changed
Base developed from a physical foundation to a reference level, while speed shifted from success or progress to rate of motion before the compound became established in motor engineering.
How it is spelled
Pattern
The silent final e in base marks the long a sound.
Pattern
The double e in speed represents the long e sound.
Pattern
The phrase is written as two separate words.

Spelled like

  • phase
  • grade
  • feed
  • need
Broken into chunks
  • base
    • baseline
    • baseplate
  • speed
    • speedometer
    • overspeed
What it sits beside

Same subject

Same shape

  • base frequency
  • base load
  • base current

motor operating points

  • Base Speed
  • maximum speed
  • minimum speed

VFD commissioning parameters

  • motor rated current
  • motor rated frequency
  • motor rated speed

Where it sits in the deck

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.

Neighbours in this phase