Why Choose the Mersen N1000121 High Voltage Transformer Protection Fuse?
The Mersen N1000121 is a high voltage DIN back-up fuse-link designed to protect transformers and associated medium voltage equipment against damaging short-circuit currents. Part of the Mersen Limitor®-PT series, it combines dependable fault interruption with controlled power dissipation for use in high voltage switchgear, controlgear and electrical distribution systems.
This fuse-link uses pure silver fuse elements, silver-plated copper terminals and a durable ceramic body to provide reliable electrical performance in demanding installations. Its back-up operating characteristic allows it to interrupt high fault currents while being coordinated with suitable protective equipment for lower-level overload conditions.
Rated at 12 kV AC and 4 A, the N1000121 incorporates an 80 N striker for fault indication or operation of compatible switchgear. Its DIN-format construction, controlled power dissipation and high breaking capacity make it suitable for transformer substations, ring main units and industrial medium voltage distribution equipment.
Key Advantages
- Designed specifically for high voltage transformer protection.
- 12 kV AC rated voltage for medium voltage systems.
- 4 A current rating for compatible transformer circuits.
- Integrated 80 N striker for fault indication and switchgear operation.
- Controlled power dissipation supports efficient switchgear design.
- High 63 kA breaking capacity for dependable fault interruption.
- Pure silver fuse elements provide consistent electrical performance.
- Durable ceramic body suitable for demanding electrical environments.
Key Features
- Mersen Limitor®-PT high voltage DIN back-up fuse-link.
- Catalogue number: 45DB120V4PT.
- Rated voltage: 12 kV AC.
- Rated current: 4 A.
- Fuse size: 56 mm diameter × 292 mm fuse body length.
- Overall product length: 358 mm.
- Integrated 80 N striker indication system.
- 63 kA maximum breaking capacity.
- VDE T4 design with controlled power dissipation.
- Manufactured in accordance with IEC 60282-1.
High voltage back-up fuse-links protect transformers by rapidly interrupting significant short-circuit currents before excessive thermal and mechanical stress can damage transformer windings, switchgear or connected distribution equipment. Their current-limiting action can also reduce the peak energy passed into a fault.
The Mersen N1000121 includes controlled power dissipation technology, helping limit heat generation within compact switchgear installations. Its integrated striker can activate compatible switching equipment or provide a clear indication when the fuse-link has operated.
Typical Applications
- Medium voltage transformer protection.
- High voltage switchgear assemblies.
- Transformer substations.
- Ring main units.
- Industrial power distribution systems.
- Utility distribution equipment.
- Compact secondary substations.
- OEM transformer controlgear.
