MERSEN FUSE NH4A 250KVA 400V GTR NH42GTR250KVA-8

Q: What is the current rating of this fuse-link?

The NH42GTR250KVA-8 has a 361 A rated current.

Mersen NH42GTR250KVA-8 NH4a gTr transformer protection fuse-link rated at 361 A and 400 V AC for transformers up to 250 kVA, featuring live gripping lugs and a top indicator.

SKU: NH42GTR250KVA-8Alt SKU: NH42GTR250KVA-8MPN: P1030482

List Price £178.53 ex VAT

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Manufacturer Lead Time

£178.53

Why Choose the Mersen NH42GTR250KVA-8 Transformer Protection Fuse-Link?

The Mersen NH42GTR250KVA-8 is a specialist DIN NH gTr low voltage fuse-link developed specifically for protecting distribution transformers. Designed for 250 kVA transformers, this NH Size 4a fuse-link has a 361 A current rating and a 400 V AC operating voltage, delivering dependable transformer protection while accommodating transformer energisation currents without nuisance operation.

Part of Mersen's trusted NH gTr transformer protection range, the NH42GTR250KVA-8 features live gripping lugs with a top-mounted indicator, enabling safe handling with an approved NH fuse puller and rapid visual identification when the fuse-link has operated. The gTr operating characteristic is specifically matched to transformer applications, providing improved selectivity over conventional gG fuse-links.

Designed for industrial substations, commercial power distribution and transformer protection systems, this fuse-link offers excellent current-limiting performance, high breaking capacity and long service life in demanding electrical installations.

Key Advantages

Designed specifically for distribution transformer protection.
Suitable for transformers up to 250 kVA.
361 A rated current.
400 V AC rated voltage.
gTr characteristic improves transformer protection and selectivity.
High current-limiting performance minimises fault energy.
Top-mounted indicator provides rapid fuse status identification.

Key Features

Mersen NH gTr transformer fuse-link series.
Catalogue number: NH42GTR250KVA-8.
Manufacturer item number: J1028729.
361 A rated current.
400 V AC rated voltage.
250 kVA transformer protection.
NH Size 4a construction.
Top-mounted indication system.
Live gripping lugs.
Body width: Approximately 72.9 mm.

Reliable Protection for Distribution Transformers

The Mersen NH42GTR250KVA-8 has been engineered specifically to match the operating characteristics of distribution transformers. Its gTr time-current characteristic tolerates transformer magnetising inrush currents while providing rapid fault clearance, protecting both the transformer and the associated electrical installation.

Compared with standard general-purpose fuse-links, the gTr characteristic offers enhanced selectivity for transformer installations. This helps minimise unnecessary fuse operation while maintaining dependable protection against overloads and short-circuit faults in industrial and commercial power systems.

Typical Applications

Distribution transformer protection.
Industrial substations.
Commercial electrical distribution systems.
Transformer switchgear.
Industrial manufacturing facilities.
Power distribution panels.

Technical Specifications

Current	361 A
Voltage	400 V
Manufacturer	Mersen
Series	NH gTr 400 V AC Fuse-Links
Model	NH42GTR250KVA-8
Manufacturer reference	J1028729
Product type	NH transformer protection fuse-link
Utilisation category	gTr
Fuse size	NH4a
Transformer rating	250 kVA
Rated current	361 A
Rated voltage	400 V AC
Current type	AC
Body width	72.9 mm
Power dissipation	28 W
Indicator	Top indicator
Gripping lugs	Live gripping lugs
RoHS	Compliant
Device Type	Fuse link
Fuse Type	NH (DIN)
Fuse Size	NH4a
Fuse Class	gTr

Frequently Asked Questions

What is the Mersen NH42GTR250KVA-8 used for?

It is designed specifically to protect distribution transformers rated up to 250 kVA against overload and short-circuit faults.

What is the current rating of this fuse-link?

The NH42GTR250KVA-8 has a 361 A rated current.

What does the gTr characteristic mean?

The gTr characteristic is developed specifically for transformer protection, allowing transformer energisation currents while providing dependable fault protection and improved selectivity.

What voltage is this fuse-link designed for?

This transformer protection fuse-link is rated for operation on 400 V AC systems.

Why does this fuse have a top indicator?

The top-mounted indicator provides clear visual confirmation when the fuse has operated, helping maintenance personnel identify and replace the fuse quickly.

Trusted by Electrical Professionals Worldwide

Mersen NH gTr transformer fuse-links are trusted by utilities, panel builders, electrical contractors and industrial engineers for delivering dependable transformer protection, excellent selectivity and high current-limiting performance.

UK delivery

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Free UK delivery on orders over £200 ex VAT. Order in-stock items before 2pm Monday to Friday for next-day delivery.

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