MERSEN FUSE H 2409UP BCKUP T442-56/6,3 45DB240V6,3PT

Why Choose the Mersen H1000139 High-Voltage Fuse?

The Mersen H1000139, catalogue number 45DB240V6,3PT, is a high-voltage DIN back-up fuse-link developed to provide reliable protection for medium-voltage transformers against the effects of short-circuit currents. As part of the Mersen Limitor®-PT range, it combines controlled power dissipation with an integrated 80 N thermal striker, making it ideal for modern air-insulated and gas-insulated switchgear installations.

Rated at 24 kV AC and 6.3 A, the H1000139 rapidly interrupts high fault currents while helping to minimise thermal and mechanical stress on transformers, switchgear and associated electrical equipment. Its controlled power dissipation design improves heat management within compact switchgear assemblies.

Manufactured using a robust ceramic body with pure silver fuse elements and silver-coated copper end caps, the fuse incorporates an 80 N thermal striker capable of operating compatible switchgear mechanisms or providing fuse operation indication. The DIN-format fuse measures approximately 56 mm in diameter and 442 mm in length.

Key Advantages

• Designed specifically for medium-voltage transformer protection.
• 24 kV AC rated voltage for distribution systems.
• 6.3 A rated current.
• Controlled power dissipation reduces operating temperatures.
• Current-limiting operation minimises equipment damage during faults.
• Integrated 80 N thermal striker enhances switchgear protection.
• Suitable for both air-insulated and gas-insulated switchgear.
• Manufactured using premium ceramic, silver and copper materials.

Key Features

• Mersen Limitor®-PT back-up fuse series.
• 24 kV AC IEC rated voltage.
• 6.3 A rated current.
• 63 kA maximum breaking capacity.
• 30 A minimum breaking current.
• 0.75 kA²s clearing I²t.
• 13 W power dissipation at rated current.
• 56 mm fuse diameter.
• 442 mm fuse length.
• 80 N thermal striker.
• Pure silver fuse elements.
• Silver-coated copper end caps with ceramic body.

Reliable Protection for Medium-Voltage Transformers

The Mersen H1000139 is a back-up current-limiting fuse specifically designed for transformer protection. It rapidly clears high fault currents before they reach their prospective peak, reducing thermal and mechanical stress on transformers, switchgear and associated equipment.

Its controlled power dissipation helps minimise temperature rise within switchgear compartments, while the integrated thermal striker enables compatible switching devices to disconnect the circuit automatically if excessive temperatures develop.

Typical Applications

• Medium-voltage transformer protection.
• Gas-insulated switchgear (GIS).
• Air-insulated switchgear.
• Transformer feeder panels.
• Industrial electrical distribution systems.
• Utility substations.
• Fuse-switch combination units.