Why Choose the Mersen W1000128 High Voltage DIN Back-up Fuse?
The Mersen W1000128 is a high-performance Limitor®-PT high voltage DIN back-up fuse designed to protect transformers against the damaging thermal and mechanical effects of short-circuit currents. Also identified by catalogue number 45DB120V40PT, it is intended for reliable use in medium voltage switchgear, controlgear and electrical distribution systems.
As part of the Limitor®-PT range, the W1000128 incorporates Controlled Power Dissipation (CPD) technology to support dependable long-term protection and reduce the risk of excessive thermal loading. Its pure silver fuse elements, silver-plated copper terminals and ceramic insulating body provide consistent electrical performance in demanding industrial and utility installations.
With a rated voltage of 12 kV AC, a rated current of 40 A and an integrated 80 N CPD striker, the Mersen W1000128 is suitable for transformer feeders and medium voltage protection assemblies. Its standard 56 mm diameter by 292 mm fuse-link size enables installation in compatible DIN fuse bases and switchgear systems.
Key Advantages
- Designed specifically for medium voltage transformer protection.
- 12 kV AC IEC rated voltage for high voltage distribution systems.
- 40 A rated current for compatible transformer circuits.
- Controlled Power Dissipation supports reliable long-term operation.
- Integrated 80 N striker supports indication and switchgear operation.
- 63 kA breaking capacity provides dependable short-circuit interruption.
Key Features
- Mersen Limitor®-PT series.
- Catalogue number: 45DB120V40PT.
- 12 kV AC IEC rated voltage.
- 40 A rated current.
- Controlled Power Dissipation technology.
- 80 N integrated CPD striker.
- Pure silver fuse elements with silver-plated copper terminals.
- VDE T4 design for medium voltage transformer protection.
High voltage back-up fuses protect transformers, cables and switchgear by limiting and interrupting substantial short-circuit currents before they cause serious thermal or mechanical damage. The Mersen W1000128 is engineered to remain stable during normal transformer operation while responding effectively when a high-level electrical fault occurs.
The integrated CPD striker provides fuse operation indication and can actuate a compatible switchgear mechanism. This supports coordinated circuit isolation, faster fault identification and safer maintenance within medium voltage power distribution installations.
Typical Applications
- Medium voltage distribution transformer protection.
- High voltage switchgear and controlgear.
- Electrical distribution substations.
- Ring main units and transformer feeders.
- Industrial medium voltage power systems.
- Utility and infrastructure distribution networks.
