Why Choose the Mersen R300004 Protistor® High-Speed Fuse?
The Mersen R300004 (PC31UD69V400TF) is a premium Protistor® Size 31 square body high-speed semiconductor fuse engineered to provide ultra-fast protection for modern power conversion equipment. Featuring an aR ultra-fast operating characteristic, it is specifically designed to protect diodes, thyristors, IGBTs and other semiconductor devices against damaging short-circuit currents.
Manufactured using precision die-cut silver fuse elements embedded in solidified sand, the R300004 delivers outstanding current limitation, low let-through energy and high interrupting capacity. Silver-plated contact surfaces, non-magnetic hardware and an integrated striker indicator ensure dependable long-term operation while simplifying maintenance and remote monitoring.
With a 400 A current rating, 690 V AC IEC and 700 V AC UL voltage ratings, the Mersen R300004 is ideally suited to industrial drives, power converters, UPS systems, renewable energy installations and other demanding power electronic applications.
Key Advantages
- Ultra-fast aR semiconductor protection fuse.
- 400 A current rating.
- 690 V AC IEC / 700 V AC UL voltage rating.
- Exceptional current-limiting performance with low I²t values.
- Integrated striker indicator for simplified maintenance.
- Designed specifically for protection of IGBTs, thyristors and diode modules.
Key Features
- Mersen Protistor® Size 31 series.
- Catalogue number: PC31UD69V400TF.
- aR ultra-fast operating characteristic.
- 400 A rated current.
- 690 V AC (IEC) / 700 V AC (UL).
- Flush-end design with metric threaded connections.
- Integrated striker indicator.
- Ceramic square body with silver-plated contact surfaces.
Reliable Protection for Power Electronics
Protistor® semiconductor fuses are specifically designed to interrupt fault currents before expensive semiconductor devices can be damaged. Their ultra-fast response and low let-through energy help improve equipment reliability, reduce maintenance costs and minimise costly production downtime.
The Size 31 Protistor® range is widely used throughout industrial automation, renewable energy systems, motor drives, UPS installations and power conversion equipment where dependable semiconductor protection is essential.
Typical Applications
- Variable speed drives (VSDs).
- Industrial motor control systems.
- Power converters and inverters.
- Industrial rectifiers.
- UPS systems.
- Renewable energy power conversion equipment.
- Protection of IGBTs, thyristors and diode modules.
