Why Choose the Mersen S079964 Protistor High-Speed Fuse?
The Mersen S079964, catalogue number FD27GB66V80T, is a high-speed cylindrical semiconductor fuse designed to protect sensitive DC power electronic equipment against damaging overloads and short-circuit currents. Part of the Mersen Protistor® 27 × 60 mm gR (gRB) series, it is specifically developed for railway power systems, auxiliary circuits and industrial DC equipment requiring rapid and dependable fault interruption.
This fuse-link offers low I²t performance to limit the energy transferred to semiconductor components during electrical faults. Its low power losses, robust ceramic body and ability to operate reliably at elevated temperatures help improve equipment availability, reduce thermal stress and support a long operational life.
With a rated current of 80 A, a rated voltage of 660 V DC and a maximum DC breaking capacity of 50 kA, the S079964 is suitable for protecting converters, rectifiers, inverters and railway auxiliary power circuits. Its integrated striker provides mechanical fuse operation indication for use with compatible monitoring and signalling accessories.
Key Advantages
- High-speed gR semiconductor fuse for full-range DC circuit protection.
- 80 A rated current for demanding power electronic applications.
- 660 V DC IEC voltage rating for railway and industrial systems.
- Low I²t performance helps minimise damage to semiconductor components.
- Maximum DC breaking capacity of 50 kA.
- Integrated striker indicator supports fuse status monitoring.
- Low power dissipation helps improve equipment efficiency.
- Designed for reliable operation at elevated temperatures.
Key Features
- Mersen Protistor® high-speed fuse series.
- Manufacturer item number S079964.
- Catalogue number FD27GB66V80T.
- 80 A rated current.
- 660 V DC IEC rated voltage.
- gR speed and utilisation characteristic.
- gRB design for semiconductor protection.
- Integrated striker for fuse operation indication.
- 27 × 60 mm cylindrical fuse format.
- Silver-plated copper ferrule terminals.
- Clip-mounting configuration.
- RoHS-compliant construction.
Reliable Protection for DC Power Electronics
Semiconductor devices such as diodes, thyristors and IGBTs can be permanently damaged within milliseconds when exposed to excessive fault current. The Mersen S079964 interrupts these currents rapidly, limiting let-through energy and helping protect valuable power electronic components from thermal and mechanical damage.
Its gR characteristic provides full-range protection against overload and short-circuit currents. Combined with its compact cylindrical construction, integrated striker and low power losses, the fuse is well suited to railway auxiliary systems and industrial DC installations where dependable protection and clear fuse status indication are essential.
Typical Applications
- Railway power and auxiliary circuits.
- Industrial DC converters.
- Semiconductor rectifier assemblies.
- Power inverters and frequency converters.
- DC motor drives and control systems.
- Battery energy storage equipment.
- Renewable energy power conversion systems.
- Industrial automation and power distribution equipment.
