Why Choose the Mersen J1000278 High Voltage DIN Back-up Fuse?
The Mersen J1000278 is a high performance DIN high voltage back-up fuse designed to protect medium voltage transformers and associated switchgear against the thermal and dynamic effects of short-circuit currents. Part of the advanced Mersen Limitor®-PTD series, it combines reliable fault interruption with controlled power dissipation for efficient operation in demanding electrical distribution systems.
Designed in accordance with IEC 60282-1 and VDE 0670 T402, the J1000278 provides excellent current-limiting performance and a maximum breaking capacity of 65 kA. Its pure silver fuse elements, silver-plated copper terminals and robust ceramic body support dependable operation, high electrical conductivity and long-term resistance to ageing.
With a rated voltage of 24 kV AC, a rated current of 20 A and an integrated 80 N thermal striker, the Mersen J1000278 is suitable for transformer protection in air-insulated and gas-insulated switchgear. Its Limitor®-PTD construction also helps reduce power losses and operating temperatures within medium voltage installations.
Key Advantages
- Reliable medium voltage transformer protection.
- 24 kV AC rated voltage for high voltage distribution systems.
- 20 A current rating for compatible transformer applications.
- High 65 kA maximum breaking capacity.
- Controlled Power Dissipation technology helps reduce heat and energy losses.
- Integrated 80 N thermal striker for compatible switchgear mechanisms.
Key Features
- Mersen Limitor®-PTD high voltage DIN back-up fuse.
- Catalogue number: 45DB240V20PTD.
- 24 kV AC rated voltage.
- 20 A rated current.
- 65 kA maximum breaking capacity.
- 3.9 kA²s clearing I²t at rated voltage.
- Integrated striker indication system.
- Ceramic body with silver fuse elements and silver-plated copper terminals.
High voltage back-up fuses interrupt substantial short-circuit currents before they can cause extensive thermal or mechanical damage to transformers, switchgear and connected distribution equipment. Their current-limiting action restricts the peak fault current and energy transferred into the protected circuit.
The Mersen Limitor®-PTD range is specifically designed for use with high voltage switchgear. Controlled Power Dissipation technology reduces operating losses, while the integrated thermal striker can activate compatible switchgear mechanisms when the fuse operates.
Typical Applications
- Medium voltage transformer protection.
- Air-insulated switchgear installations.
- Gas-insulated switchgear assemblies.
- Electrical substations and distribution networks.
- Industrial medium voltage power systems.
- Utility and infrastructure transformer installations.
