Why Choose the Mersen B221445 Protistor® High-Speed Fuse?
The Mersen B221445, catalogue number FR27GB80V63T, is a high-speed cylindrical semiconductor fuse designed to provide full-range protection for sensitive power electronic equipment. Part of the Mersen Protistor® 27 × 60 mm gR range, it delivers extremely fast fault interruption to help protect power semiconductors against overloads and short circuits.
Rated at 63 A and 800 V AC, the B221445 is suitable for small power conversion systems, industrial motor drives, UPS equipment and other applications containing IGBTs, thyristors, diodes or rectifiers. Its die-cut fuse elements are embedded in solidified sand to control arcing, reduce let-through energy and support dependable interruption of high prospective fault currents.
The fuse incorporates an integrated mechanical striker, enabling compatible fuse holders, microswitches or monitoring devices to signal when the fuse has operated. With a maximum breaking capacity of 90 kA, low clearing I²t and excellent cycling capability, the FR27GB80V63T provides reliable protection for demanding industrial power-electronic installations.
Key Advantages
- Ultra-fast gR full-range semiconductor protection.
- Protects against both overload and short-circuit currents.
- 63 A rated current for industrial power-electronic equipment.
- 800 V AC IEC voltage rating.
- Integrated mechanical striker for fuse-operation indication.
- Low clearing I²t helps minimise stress on sensitive semiconductors.
- 90 kA breaking capacity for reliable fault interruption.
- Compact cylindrical design for clip-mounted fuse holders.
Key Features
- Mersen Protistor® high-speed cylindrical fuse.
- Item number: B221445.
- Catalogue number: FR27GB80V63T.
- 63 A rated current.
- 800 V AC rated voltage.
- gR operating characteristic.
- gRB design classification.
- 90 kA maximum breaking capacity.
- Integrated striker indication system.
- Silver-plated copper ferrule terminals.
- High-strength ceramic fuse body.
- RoHS compliant construction.
Full-Range Protection for Power Semiconductors
The Mersen B221445 uses an ultra-fast gR operating characteristic to protect semiconductor components throughout the complete overcurrent range. Unlike partial-range semiconductor fuses that primarily address short-circuit faults, this full-range fuse is designed to clear both overload currents and high-level semiconductor faults.
Its low let-through energy helps limit the thermal and electrical stress applied to expensive semiconductor devices. The fuse also offers strong cycling capability, making it suitable for equipment exposed to repetitive load changes, starting currents and fluctuating operating conditions.
Integrated Mechanical Striker
The FR27GB80V63T contains a built-in striker that activates when the fuse operates. When installed in a compatible fuse holder, the striker can trigger a visual indicator, auxiliary microswitch or remote monitoring circuit, allowing maintenance personnel to identify an operated fuse quickly.
This indication feature can reduce troubleshooting time and help minimise equipment downtime in industrial installations containing multiple fuse-protected power circuits.
Typical Applications
- Small power converters.
- Variable frequency drives.
- Industrial motor-drive systems.
- Uninterruptible power supplies.
- Rectifiers and inverter circuits.
- Industrial automation equipment.
- Semiconductor switching systems.
- Power-electronic control panels.
- Equipment operating at up to 800 V AC.
