Transformer fuse-link ratings by kVA and primary voltage — Cooper Type D, Type X/KS, Kearney Type K/T, Type 200, and Type QA. Field reference for sizing overhead cutout fuses.
| kVA | 2.4 kV | 4.16 kV | 4.8 kV | 7.2 kV | 7.62 kV | 12 kV | 13.2 kV | 13.8 kV | 14.4 kV | 22.9 kV |
|---|---|---|---|---|---|---|---|---|---|---|
| 3 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| 5 | 3 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| 7.5 | 6 | 3 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 1 |
| 10 | 6 | 3 | 3 | 2 | 2 | 1 | 1 | 1 | 1 | 1 |
| 15 | 8 | 6 | 6 | 3 | 3 | 2 | 2 | 2 | 2 | 1 |
| 25 | 15 | 8 | 8 | 6 | 6 | 3 | 3 | 3 | 3 | 2 |
| 37.5 | 25 | 12 | 10 | 8 | 8 | 6 | 3 | 3 | 3 | 3 |
| 50 | 30 | 15 | 15 | 10 | 10 | 6 | 6 | 6 | 6 | 3 |
| 75 | 50 | 25 | 25 | 15 | 15 | 8 | 8 | 8 | 8 | 6 |
| 100 | 65 | 30 | 30 | 20 | 20 | 12 | 10 | 10 | 10 | 6 |
| 150 | 100 | 50 | 50 | 30 | 30 | 20 | 15 | 15 | 15 | 10 |
| 167 | 100 | 65 | 50 | 30 | 30 | 20 | 20 | 20 | 15 | 10 |
| 200 | 140 | 65 | 65 | 40 | 40 | 25 | 20 | 20 | 20 | 12 |
| 250 | 140 | 80 | 80 | 50 | 50 | 30 | 25 | 25 | 25 | 15 |
| 333 | 140 | 100 | 100 | 65 | 65 | 40 | 40 | 40 | 30 | 20 |
| 500 | 200 | 140 | 140 | 100 | 100 | 65 | 50 | 50 | 50 | 30 |
The fuse-sizing data on this page is sourced from Eaton / Cooper Power Series published literature and is provided for general reference and educational purposes only. Fuse coordination, transformer protection, and overcurrent device selection are engineering decisions that depend on system configuration, fault current, coordination studies, and your utility's specific standards — this page is not a substitute for that analysis. Enerzas makes no representation that this data is current, complete, or appropriate for any specific installation. Always verify against your utility's engineering standards, the manufacturer's current published tables, and applicable codes (NESC, CSA C22.3, IEEE, OSHA 1910.269) before selecting or installing a fuse. When in doubt, consult a licensed professional engineer or your utility's standards group. Enerzas assumes no liability for the use or misuse of this data.