Industrial Engineer · phase 10 of 16 · noun
Constant Torque Region
Operating range, usually at or below base speed, in which rated motor flux allows approximately constant torque.
The Explain card
- Plain English
- The constant torque region is the speed range from zero up to base speed, where the drive can keep the flux at rated value and the motor can deliver full torque. Voltage rises in step with frequency the whole way.
- Example
- A conveyor runs anywhere from 10 to 60 hertz with a full belt. Across that whole range the motor can produce its rated torque, so the belt starts and holds load at any speed.
- Why it matters
- Loads that need the same torque at every speed have to live in this region, and the drive's ratings assume it. At the very bottom, cooling from the shaft fan disappears, so full torque at 5 hertz for long periods needs a separate blower.
- Hook
- Full torque from a standstill up to the corner.
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 kept conveyor acceleration within the Constant Torque Region before testing operation above base frequency.
Why these words
- constant Latin constans, standing firm modifies torque to describe its characteristic on the operating map
- torque Latin torquere, to twist names the mechanical quantity used to label the region
- region Latin regio, boundary or district serves as the head noun for a bounded portion of an operating map
Where it came from
- Origin
- English engineering compound built from constant, torque, and region, ultimately from Latin constans, torquere, and regio
- Entered the language
- 20th century
- What changed
- Constant moved from steadfast to unchanging, torque became the technical name for twisting action, and region expanded from a geographic district to a bounded part of a technical operating map.
How it is spelled
- Pattern
- constant uses the adjective ending -ant
- Pattern
- region keeps soft g before i
- Breaks the pattern
- torque retains the French-derived final -que for the sound /k/
Spelled like
- resistant
- observant
- giant
- digital
- plaque
- technique
Broken into chunks
-
con-stant
- constancy
- inconstant
-
torque
- torqued
- torquing
-
re-gion
- regional
- regionalize
What it sits beside
Same subject
- base speed
- field weakening
- constant power region
- volts-per-hertz control
Same shape
- constant power region
- constant torque load
- variable frequency drive
VFD operating regions
- constant torque region
- constant power region
motor load profiles
- constant torque load
- variable torque load
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.
