Why Choose the Mersen NH4A2GTR400KVA Transformer Protection Fuse-Link?
The Mersen NH4A2GTR400KVA is a specialist DIN NH gTr fuse-link designed to protect low-voltage distribution transformers against overloads and short-circuit faults. Part of Mersen's professional NH gTr 400 V AC transformer protection range, it features an operating characteristic specifically matched to transformer behaviour.
The gTr characteristic enables the fuse-link to tolerate normal transformer magnetising inrush currents while providing dependable current-limiting protection during sustained overloads and severe electrical faults. It also supports effective selectivity with downstream gG fuse-links, helping isolate affected circuits without unnecessarily interrupting the wider installation.
Designed for 400 kVA three-phase transformers, the NH4A2GTR400KVA has a nominal current rating of approximately 577 A at 400 V AC. Its NH4a construction, centre indicator and live gripping lugs make it suitable for transformer incomers, industrial substations and main low-voltage distribution switchboards.
Key Advantages
- Purpose-designed for low-voltage distribution transformer protection.
- Matched to 400 kVA three-phase transformer applications.
- 577 A nominal current rating at 400 V AC.
- gTr characteristic accommodates normal transformer energisation currents.
- Provides effective overload and short-circuit fault protection.
- Supports selectivity with downstream gG protection devices.
Key Features
- Mersen NH gTr transformer fuse-link range.
- Catalogue number: NH4A2GTR400KVA.
- Manufacturer reference: G1030521.
- NH4a fuse format.
- 400 kVA transformer rating.
- Approximately 577 A nominal current.
- 400 V AC rated operating voltage.
- gTr full-range transformer protection characteristic.
- Centre-mounted fuse operation indicator.
- Live gripping lugs for use with a suitable NH fuse puller.
- DIN NH blade-contact construction.
- Designed for installation by qualified electrical professionals.
Transformer energisation can produce a short-duration magnetising current significantly greater than the normal operating current. The Mersen NH4A2GTR400KVA is designed to withstand this expected inrush without unnecessary operation while remaining responsive to genuine overload and short-circuit conditions.
Its current-limiting performance helps reduce thermal and electrodynamic stress on transformers, conductors and switchgear during a fault. The dedicated gTr characteristic also assists coordination with downstream protective devices, supporting reliable and selective operation across the distribution system.
Typical Applications
- Protection of 400 kVA distribution transformers.
- Industrial and commercial substations.
- Transformer incomer circuits.
- Main low-voltage switchboards.
- Factory and process power distribution systems.
- Utility and infrastructure electrical installations.
