Industrial Engineer · phase 9 of 16
Overload Rating
Permitted output current above the continuous rating for a stated magnitude, duration, and duty cycle.
The Explain card
- Plain English
- The overload rating says how far above continuous current the drive can go, for how long, and how often. A typical constant torque rating allows 150 percent for 60 seconds, and some drives add a short 180 or 200 percent peak.
- Example
- A crusher jams and the motor demands 140 percent for twenty seconds. A drive with a 150 percent for one minute rating rides through it and trips only if the jam lasts.
- Why it matters
- The overload is what starts stuck loads and survives brief jams, and it is used up by heat, so two overloads back to back get less than one. Sizing without knowing the duty cycle is guessing.
- Hook
- How hard you can push, and for how long.
Where it sits in the deck
Phase 9: VFD Ratings, Sizing, and Motor Data
Nameplate arithmetic, where the currents, voltages and duty ratings decide whether a drive can actually run the motor you bolted it to.
