Positrol® Fuse Links
Fuse cutouts have an essential role in system and equipment protection on overhead distribution systems. The key determinant of a cutout’s ability to function properly is the fuse link it uses. Failure of the fuse link to perform as planned can result in miscoordination with other protective devices, nuisance operations (“sneakouts”), and needless outages. To a utility that’s dollars and cents—and not just the cost of the replacement fuse link. The expense of finding and replacing fuse links that sneak out can cost many times the up-front savings achieved through the use of less-expensive fuse links.
S&C’s Positrol Fuse Links eliminate nuisance fuse operations and, at the same time, provide reliable protection in the event of a fault within the cutout’s zone of protection. They’re manufactured in accordance with a quality system certified to ISO9001:2000.
Positrol Fuse Links offer features that are unavailable in any other fuse link.
- Nondamageability. Positrol Fuse Links have permanently accurate time-current characteristics. They’re unaffected by mechanical shock, vibration, or transient current surges that heat the element nearly to the severing point — eliminating sneakouts.
- Close melting-current tolerance. Positrol Fuse Links have a melting-current tolerance that’s typically half that of other fuse links — permitting closer fusing for improved protection, more precise series coordination for enhanced service reliability.
- Superior fault-interrupting performance. Positrol Fuse Links provide unsurpassed protection against all types of faults, including low-current transformer secondary-side faults.
Universal Style Positrol Fuse Links provide unsurpassed secondary-fault performance for applications through 14.4 kV. Extra-Performance Style Positrol Fuse Links extend that superior performance to three-phase applications through 24.9 kV, and to single-phase-to-neutral applications through 38 kV
| Speed | Ampere Range |
|---|---|
| S&C Standard | 1–200 |
| S&C “K” | 6–200 |
| S&C “T” | 6–200 |
| S&C “N” | 5–200 |
| S&C “QR” | 1–200 |
| S&C Coordinating | 101–103 |
Speed Comparison Example
| Style | Overall Length, Inches (mm) |
Speed | Rating, Amperes |
|---|---|---|---|
 Universal Not Usable in Discontinued S&C Positect® Cutouts |
23 (584) | S&C Standard | 1 through 200 |
| S&C “K” | 6K through 200K | ||
| S&C “T” | 6T through 200T | ||
| 29 (737) | S&C “QR” | 1QR through 200QR | |
| S&C “N” | 5N through 200N | ||
| 23 (584) | S&C Coordinating | 101 through 103 | |
|
Universal Usable in Discontinued S&C Positect® Cutouts |
23 (584) | S&C Standard | 1 through 100 |
Extra-Performance Not Usable in Discontinued S&C Positect® Cutouts) |
29 (737) | S&C Standard | 1 through 100 |
| S&C “K” | 6K through 200K | ||
| S&C “T” | 6T through 200T | ||
| S&C “QR” | 1QR through 200QR | ||
Indicating Usable Only in Discontinued S&C Positect® Cutouts |
10 (254) | S&C Standard | 3 through 100 |
Open Usable Only in Discontinued Open Link Cutouts |
8 (203) | S&C Standard | 1 through 25 |