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MERSEN FUSE NH4AC 400KVA 400V GTR MI NH4AGTR400KVA
Mersen NH4AGTR400KVA DIN NH size 4a gTr fuse-link rated at 577 A and 400 V AC, designed to protect 400 kVA low-voltage distribution transformers.
£105.67
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.
Reliable Protection for Distribution Transformers
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.
Technical Specifications
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| Voltage | 400 V | |
|---|---|---|
| Device Type | Fuse link | |
| Fuse Type | NH (DIN) | |
| Fuse Size | NH4a | |
| Fuse Class | gTr | |
| Current | 577 A | |
| Manufacturer | Mersen | |
| Series | NH gTr 400 V Transformer Fuse-Links | |
| Model | NH4AGTR400KVA | |
| Item number | D1028724 | |
| Product type | NH transformer protection fuse-link | |
| Fuse utilisation category | gTr | |
| Breaking range | Full range | |
| Fuse size | NH4a | |
| Transformer rating | 400 kVA | |
| Rated current | 577 A | |
| Rated voltage | 400 V AC | |
| Voltage type | AC | |
| Indicator position | Centre indicator | |
| Gripping-lug type | Live / non-isolated | |
| Contact type | Blade contacts | |
| Body material | Ceramic | |
| Body width | 72.9 mm | |
| Application | Low-voltage distribution transformer protection | |
| Installation system | Compatible DIN NH fuse base or switch-fuse assembly | |
| HS Code | 85361090 | |
| Country of Manufacture | Hungary |
Frequently Asked Questions
What is the Mersen NH4AGTR400KVA used for?
It is designed to protect 400 kVA low-voltage distribution transformers against overload and short-circuit conditions while tolerating normal transformer energisation currents.
What is the rated current of this fuse-link?
The Mersen NH4AGTR400KVA has a rated current of 577 A.
What voltage is the NH4AGTR400KVA rated for?
It is rated for use on electrical systems operating at up to 400 V AC.
What does the gTr characteristic mean?
The gTr characteristic identifies a full-range transformer fuse-link with operating behaviour matched to distribution transformers, including tolerance of normal magnetising inrush currents.
Does this fuse-link include an operation indicator?
Yes. The NH4AGTR400KVA includes a centre-mounted indicator to help qualified personnel identify when the fuse-link has operated.
Trusted Transformer Protection Worldwide
Mersen NH gTr fuse-links are widely specified by electrical engineers, switchgear manufacturers and industrial maintenance teams for dependable transformer protection, selective fault coordination and reliable operation in low-voltage distribution systems.
