Why Choose the Mersen F209305 High-Voltage Back-Up Fuse?
The Mersen F209305, catalogue reference 45DB120V6,3P, is a high-voltage DIN back-up fuse-link designed to protect distribution transformers against the damaging effects of short-circuit currents. As part of the Mersen Limitor®-P series, it provides dependable transformer protection for medium-voltage switchgear and power distribution systems.
Rated at 12 kV AC with a 6.3 A current rating, the F209305 is manufactured using a ceramic fuse body, pure silver fuse elements and silver-plated copper end caps to provide long service life and reliable electrical performance. It is designed in accordance with IEC 60282-1 and the VDE T4 specification for medium-voltage transformer protection.
An integrated 80 N striker provides positive mechanical indication and can operate compatible switchgear trip mechanisms. With a maximum breaking capacity of 63 kA, the fuse rapidly interrupts severe fault currents before they can damage transformers or associated equipment.
Key Advantages
- High-voltage DIN back-up fuse for transformer protection.
- 12 kV AC rated voltage.
- 6.3 A rated current.
- 63 kA breaking capacity for dependable fault interruption.
- Integrated 80 N striker for indication and switchgear operation.
- Current-limiting design reduces thermal and mechanical fault stress.
- Ceramic body with silver fuse elements for reliable performance.
- Suitable for air-insulated and gas-insulated medium-voltage switchgear.
Key Features
- Mersen Limitor®-P back-up fuse series.
- Manufacturer item number F209305.
- Catalogue number 45DB120V6,3P.
- 12 kV AC IEC rated voltage.
- 6.3 A rated current.
- 63 kA maximum breaking capacity.
- 30 A minimum breaking current.
- Total clearing I²t of 1 kA²s.
- Power dissipation of approximately 8 W.
- Integrated 80 N standard striker.
- DIN clip-mounted construction.
- IEC 60282-1 compliant.
The Mersen F209305 rapidly interrupts high fault currents before they can damage transformers and associated switchgear. Its current-limiting characteristics reduce the thermal and mechanical energy released during fault conditions, helping improve equipment reliability and minimise downtime.
As a back-up fuse-link, the F209305 is intended to provide high short-circuit protection and should be coordinated with suitable overload protection. Correct selection should always consider transformer rating, prospective fault current and switchgear manufacturer recommendations.
Typical Applications
- Distribution transformer protection.
- Medium-voltage substations.
- Air-insulated switchgear.
- Gas-insulated switchgear.
- Industrial electrical distribution.
- Utility power networks.
- Commercial power infrastructure.
- Medium-voltage feeder protection.
