Why Choose the Mersen Q221251 Protistor® High-Speed Semiconductor Fuse?
The Mersen Q221251 is a Protistor® BS88-4 British Standard high-speed semiconductor fuse designed to provide exceptional protection for sensitive power semiconductor devices. Manufactured to IEC 60269-1, IEC 60269-4, VDE 636-23 and BS88-4 standards, it delivers extremely fast fault interruption for modern industrial power electronic equipment.
With a 63 A current rating, 690 V AC IEC / 700 V AC UL voltage rating and a 17 × 49 mm BS88-4 fuse-link design, the Q221251 offers reliable protection for diodes, thyristors, GTOs and IGBT devices used in drives, UPS systems, converters and industrial inverters. The fuse is manufactured using pure silver elements embedded in solidified sand, providing low let-through energy (I²t), excellent current limitation and a high breaking capacity.
As part of Mersen's internationally recognised Protistor® semiconductor protection range, the Q221251 helps reduce damage to expensive power electronics, minimise downtime and improve equipment reliability in demanding industrial environments.
Key Advantages
- Designed specifically for semiconductor protection.
- 63 A rated current.
- 690 V AC IEC / 700 V AC UL rated.
- Extremely fast-acting aR characteristic.
- Current-limiting design with low I²t.
- High 200 kA AC breaking capacity.
Key Features
- Manufacturer: Mersen.
- Series: Protistor® BS88-4.
- Catalogue number: BS17UZ69V63.
- 17 × 49 mm British Standard fuse-link.
- aR ultra-fast semiconductor protection.
- Pure silver fuse elements.
- Solidified sand arc-quenching construction.
- Suitable for worldwide industrial applications.
Reliable Protection for Power Electronics
The Mersen Q221251 has been engineered specifically for protecting semiconductor devices where conventional fuses may not react quickly enough. Its ultra-fast aR operating characteristic limits fault energy before excessive thermal stress can damage valuable power electronic components.
Typical installations include variable speed drives, UPS systems, industrial inverters, converters and similar equipment operating at up to 690 V AC, where dependable semiconductor protection is essential for maintaining system reliability.
Typical Applications
- Variable frequency drives (VFDs).
- Industrial UPS systems.
- Power converters.
- Industrial inverters.
- Motor drives.
- Semiconductor protection circuits.
