Industrial Engineer · phase 13 of 16 · noun
Bonding
Low-impedance connection of drive, enclosure, cable shield, and motor frame to control fault and high-frequency currents.
The Explain card
- Plain English
- Bonding is connecting the drive, its enclosure, the cable shield and the motor frame together with low impedance at high frequency. Long thin green wires are fine for 60 hertz and nearly useless for the frequencies PWM produces.
- Example
- A cable shield is terminated with a 360 degree clamp at the drive and at the motor, and the motor frame is bonded to the drive backplane with a wide flat strap. The common mode current now has a short loop.
- Why it matters
- Most drive noise problems are bonding problems, and they show up as interference, nuisance trips and bearing damage. Wide, short and flat are the rules, and a pigtail on a shield undoes the shield.
- Hook
- Give the noise a short way home or it will find a long one.
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 verifies bonding among the drive cabinet, shield clamps, and motor frame before energizing the feeder.
How it is built
- bond base bind or join
- -ing suffix an action, process, or result
Where it came from
- Origin
- English bond, from Middle English bond and Old Norse band, plus the noun-forming suffix -ing
- Entered the language
- 17th century
- What changed
- It began as a general word for binding or joining and later acquired specialized electrical uses.
How it is spelled
- Pattern
- A consonant-final base takes -ing directly.
- Pattern
- The final d in bond is retained without doubling.
Spelled like
- grounding
- shielding
- fastening
Broken into chunks
-
bond
- bonded
- bondholder
- bondage
-
-ing
- grounding
- screening
- shielding
What it sits beside
Same subject
- bonding jumper
- protective earth
- shield clamp
- grounding bar
- equipotential bonding
Same shape
- grounding
- shielding
- screening
connection hardware
- bonding jumper
- shield clamp
- grounding bar
protective conductors
- protective earth conductor
- equipment grounding conductor
Where it sits in the deck
Phase 13: VFD Power Quality, Wiring, and Motor Protection
Harmonics, reflected waves, shielded cable and bearing currents: the side effects a drive inflicts on everything around it.
