Short Circuit
Results are for estimation only. Always verify with detailed system studies for switchgear sizing and protection coordination.
IEEE C37kVA
%Z
kV
V
MVA
Typical Impedance Values (%Z)
| kVA | %Z Oil | %Z Dry | X/R |
|---|---|---|---|
| ≤ 500 | 4.0% | 4.5–6.0 | 3–5 |
| 500–1,000 | 5.0% | 5.0–6.0 | 5–8 |
| 1,000–2,500 | 5.5–6.0% | 6.0 | 8–12 |
| 2,500–10,000 | 6.0–7.0% | 6.0–7.0 | 10–15 |
| > 50,000 | 10.0–15.0% | — | 20–40 |
Specify short-circuit-rated transformers and switchgear
Once you've benchmarked the prospective fault current, browse the transformer and switchgear ranges KEMA short-circuit certified for your duty, or continue refining the design with the cable-sizing companion tool.