Why Choose the Mersen K300021 Protistor® High-Speed Fuse?
The Mersen K300021 (PC31UD69V315D1A) is a premium square body high-speed semiconductor fuse designed to provide exceptional protection for sensitive power electronic devices. Part of the trusted Mersen Protistor® size 31 series, this ultra-fast aR fuse delivers reliable protection for diodes, thyristors, IGBTs and other semiconductor components used in industrial power conversion systems.
Engineered for demanding industrial environments, the K300021 combines rapid fault interruption with a high breaking capacity to minimise damage caused by short circuits. Its silver-plated contacts, ceramic body and solidified sand construction provide excellent electrical performance, low let-through energy and dependable long-term reliability for mission-critical applications.
With a rated current of 315 A and a 690 V AC IEC / 700 V AC UL voltage rating, the K300021 is ideally suited for variable speed drives, UPS systems, industrial converters, renewable energy equipment and other high-power electronic installations requiring dependable semiconductor protection.
Key Advantages
- Ultra-fast aR semiconductor protection fuse.
- 315 A current rating for industrial power applications.
- 690 V AC IEC / 700 V AC UL voltage rating.
- Protects IGBTs, thyristors, diodes and other semiconductor devices.
- High interrupting capacity for superior fault protection.
- Integrated striker indicator for remote fuse monitoring.
Key Features
- Mersen Protistor® size 31 series.
- Catalogue number PC31UD69V315D1A.
- 315 A rated current.
- 690 V AC IEC / 700 V AC UL rated voltage.
- aR ultra-fast operating characteristic.
- DIN 110 blade contacts.
- Integrated striker indicator.
- Silver-plated contact surfaces.
- Ceramic body with solidified sand arc-quenching technology.
- Low I²t performance for semiconductor protection.
Reliable Semiconductor Protection for Industrial Power Systems
High-speed semiconductor fuses are specifically engineered to interrupt fault currents before expensive power electronic devices can be damaged. Their ultra-fast operation and low let-through energy help maximise equipment reliability while reducing maintenance costs and unplanned downtime.
The Mersen Protistor® size 31 range is widely used by OEMs and industrial engineers to protect modern power conversion equipment, offering dependable performance in demanding electrical installations.
Typical Applications
- Variable speed drives.
- Industrial power converters.
- IGBT inverter protection.
- Thyristor and diode rectifiers.
- UPS systems.
- Renewable energy inverters.
- Motor control centres.
- Industrial automation equipment.
