Industrial Engineer · phase 9 of 16
SCCR
Short-Circuit Current Rating, the maximum prospective fault current an assembly can safely withstand when applied as specified.
The Explain card
- Plain English
- The short circuit current rating is the maximum fault current a drive or a panel can safely withstand when protected the way the manufacturer specifies. It is a rating of the assembly, with the fuses or breaker that go with it.
- Example
- A drive is marked 100 kiloamps SCCR when protected by a particular class of fuse. Installed behind a different breaker, the rating drops to whatever the drive alone can take, which may be 5 kiloamps.
- Why it matters
- A panel with a lower SCCR than the available fault current at its terminals is an explosion waiting for a fault, and an inspection failure before that. The panel label carries the number, and the protection has to match what the label assumed.
- Hook
- What the enclosure can survive on the worst day.
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.
