Fuse link - NH1 gG 250A/400V - time-lag 004184119

Knife fuse links – reliable installation protection

Knife fuse links NH are industrial devices designed to protect electrical installations against the effects of short circuits and overloads. Their construction and electrical parameters comply with standards PN-93/E-06160 (gF), PN-IEC-269 and VDE 0636. This model, designated as NH1 gG 250A/400V, provides effective protection of circuits, reacting to both overloads and short circuits.

The fuse is characterized by a time-delay characteristic (gG), which means that it allows for short-term exceeding of the rated current without disconnecting the circuit – this is particularly important when starting devices with electric motors or other loads with high inrush current. The rated current of 250A at a voltage of 400V AC makes this fuse suitable for medium and large installations.

Construction and distinguishing features

The fuse is made of high-quality materials, which guarantees its reliability and durability. The steatite body provides thermal stability, and the silver-plated brass knife contacts minimize electrical resistance and ensure a secure connection. Aluminum covers protect against corrosion. The fuse is filled with quartz sand of a special granulation, which affects the high short-circuit breaking capacity – up to 120kA – and the stability of electrical parameters.

Particular attention is paid to the dual operating indicator: a red eye in the central part of the ceramic body and a springy plate on the top cover. This system ensures easy and reliable identification of a blown fuse, even remotely – the upper indicator allows cooperation with the NVS 5 microswitch for remote signaling of the fuse status. Additionally, the silver-plated knife contacts facilitate mounting in a fuse base or fuse disconnector.

Application and compliance with standards

NH1 gG 250A/400V knife fuse links are widely used in industrial, commercial installations and in public buildings. They are ideal for protecting cables, devices and circuits powering electric motors. They meet the requirements of IEC 60269-1 and IEC 60269-2 standards, which confirms their safety and compliance with applicable standards. The total Joule integral of switching is 716000 A²s and the pre-arcing 135200 A²s, which proves the high energy efficiency of the device during operation. Power losses are 16.5W at rated current.