Why Choose the Mersen NH4A2GTR800KVA Transformer Protection Fuse?
The Mersen NH4A2GTR800KVA is a high-capacity NH transformer protection fuse-link designed to protect low-voltage distribution transformers against overloads and short-circuit currents. Its specialised gTr operating characteristic is adapted to transformer behaviour, helping the fuse tolerate normal energisation currents while providing reliable protection against damaging electrical faults.
As part of Mersen's NH gTr fuse-link range, the NH4A2GTR800KVA supports effective selectivity with downstream gG fuse-links. This allows faults to be isolated at the appropriate point in the distribution network, helping reduce unnecessary system outages and protect transformers, cables and connected switchgear.
Rated for an 800 kVA transformer, the fuse-link has a rated current of 1,155 A and an operating voltage of 400 V AC. Its NH4a construction, centre-mounted indicator and live gripping lugs make it suitable for high-current industrial and commercial transformer installations using compatible NH fuse bases or fuse-switch disconnectors.
Key Advantages
- Purpose-designed gTr fuse-link for transformer protection.
- 800 kVA transformer rating for high-capacity distribution systems.
- 1,155 A rated current at 400 V AC.
- High 100 kA AC breaking capacity for dependable fault interruption.
- Transformer-specific time-current characteristic accommodates normal inrush currents.
- Supports effective selectivity with downstream gG fuse-links.
- Centre-mounted indicator helps identify when the fuse-link has operated.
Key Features
- Mersen NH gTr transformer fuse-link series.
- DIN NH4a fuse size.
- 800 kVA transformer capacity.
- 1,155 A rated current.
- 400 V AC rated operating voltage.
- gTr full-range transformer protection characteristic.
- 100 kA AC rated breaking capacity.
- Centre-mounted fuse operation indicator.
- Live, non-insulated gripping lugs.
- Standard NH blade contacts.
- 98 mm body width.
Transformers can draw substantial magnetising inrush current when energised, so their protective devices must tolerate temporary current peaks without operating unnecessarily. The Mersen NH4A2GTR800KVA uses a gTr characteristic developed specifically for transformer circuits, providing protection that is better matched to transformer loading than a general-purpose fuse-link.
The fuse-link can carry elevated current for defined periods while still providing timely disconnection during sustained overloads and short circuits. When correctly selected and installed, it helps protect transformer windings and associated distribution equipment while supporting continuity across the wider electrical system.
Typical Applications
- Protection of 800 kVA low-voltage distribution transformers.
- Industrial substations and transformer rooms.
- Commercial building electrical distribution systems.
- Manufacturing and production facility power networks.
- Transformer feeder switchboards and distribution panels.
- NH fuse-switch disconnectors and compatible NH4a fuse bases.
