Why Choose the Mersen NH4AGTR400KVA Transformer Protection Fuse?
The Mersen NH4AGTR400KVA is a high-performance DIN NH size 4a gTr fuse-link specifically designed to protect low-voltage distribution transformers. Rated for a transformer capacity of 400 kVA, it provides dependable full-range protection on 400 V AC electrical systems while accommodating the temporary magnetising inrush currents produced when transformers are energised.
Its specialised gTr operating characteristic is matched to the time-current behaviour of distribution transformers. This helps provide effective protection against overload and short-circuit conditions while supporting selective coordination with downstream gG fuse-links, reducing unnecessary disruption to connected electrical circuits.
The NH4AGTR400KVA has a rated current of 577 A and features a durable ceramic body, blade contacts, live gripping lugs and a centrally positioned fuse-operation indicator. Its standard NH4a format enables installation in compatible NH fuse bases, switch-fuse units and transformer distribution assemblies.
Key Advantages
- Purpose-designed for 400 kVA distribution transformer protection.
- Specialised gTr time-current characteristic matched to transformer behaviour.
- 577 A rated current for 400 V transformer applications.
- Withstands normal transformer magnetising inrush currents.
- Supports selective coordination with downstream gG fuse-links.
- Centre indicator assists with identifying an operated fuse-link.
Key Features
- Mersen NH gTr transformer protection fuse-link.
- DIN NH size 4a construction.
- 400 kVA transformer rating.
- 577 A rated current.
- 400 V AC rated voltage.
- Full-range gTr operating characteristic.
- Centre-mounted fuse-operation indicator.
- Live, non-isolated gripping lugs.
- Robust ceramic fuse body.
- Standard blade-contact format.
Distribution transformers can produce high magnetising currents when first energised. The gTr characteristic is designed to tolerate this normal temporary inrush while still operating under sustained overload or short-circuit conditions that could damage the transformer and associated electrical equipment.
The Mersen NH4AGTR400KVA also assists with selective protection between the transformer fuse and downstream gG fuse-links. Correct fuse coordination can help isolate faults closer to their source, maintaining power to unaffected parts of an electrical distribution system.
Typical Applications
- 400 kVA low-voltage distribution transformers.
- Transformer secondary-side protection.
- Industrial substations and power distribution systems.
- Commercial building electrical infrastructure.
- Transformer switch-fuse assemblies.
- Low-voltage switchgear installations.
- OEM transformer and distribution equipment.
