Double Indicator NH Fuse Link 160A 400A 630A Knife Fuse Manufacturer

Introduction

Double-indicator NH fuses are similar to standard NH knife-blade fuses but feature visual indicators on both ends of the fuse link. Like their single-indicator counterparts, they provide robust low-voltage fuse protection in industrial and power distribution applications.
An NH fuse link DIN 43620 / IEC 60269‑2 consists of a high-performance ceramic body with blade contacts; double-indicator models include two internal spring flags – one at each end – that pop out when the fuse element blows. This dual indication ensures the blown condition is visible from either side of a switchgear panel or fuse block, which can be advantageous in multi-phase or hard-to-access installations.
Otherwise, double-indicator NH fuses retain the same full-range gG characteristics as standard NH fuses: wide current ranges 2–630 A and very high breaking capacities up to 120 kA at 500 VAC.
GRL’s double-indicator NH fuse links are fully compliant with IEC 60269-2. They are CE-certified, offering reliable overload and short-circuit protection for industrial control equipment, panel boards, and energy distribution systems.

Structure and Features

Double-indicator NH fuse links are constructed like single-indicator ones, with the main difference being the indicator. The fuse body is a flame-retardant porcelain tube filled with high-purity silica sand, capped by stamped aluminum-alloy covers. Two identical spring-operated trip indicators are incorporated (one under each cover); when the fuse element melts under fault, both flags pop out of the ends. The cover plates and contacts are mirror images, each end having a copper knife blade that fits into the fuse holder. Other components – high-strength nylon plug, copper fuse element, etc. – are the same quality as single-indicator fuses.

The double indication means maintenance personnel can see which phase (or which end) is blown from either side of the panel, improving diagnostic speed in three-phase or multi-fuse arrangements. GRL double-indicator NH fuses use the same premium materials and precision assembly as our other NH series, ensuring consistent electrical performance and reliable operation in harsh industrial environments.

Technical Specifications

Advantages and Selling Points

• Dual Visual Feedback: Two trip indicators allow confirmation of fuse status from either end. In a multi-phase panel, you can inspect from either side and immediately spot a blown fuse element.

• High-Performance Protection: These fuses interrupt high short-circuit currents (e.g., 50 kA @ 690 VAC) and provide fast overload isolation. The full-range (gG) characteristic means one fuse link handles both short-circuits and overloads in a circuit.

• Wide Range of Sizes: Available in NH00, NH1, NH2, NH3, etc., covering 2–630 A. The blade lengths (~78–150 mm) and body sizes match NH standards, so they fit any NH fuse holder or switch-disconnector.

• Robust Construction: Features the same heavy-duty build as single-indicator types. The high-strength aluminum cover with stiffness ribs and porcelain body ensure safe operation under fault. The integrated copper contacts and high-purity fuse element guarantee precise melting characteristics.

• Industrial Applications: Ideal for use as panel fuses, switchgear fuses, or busbar system fuses in power distribution systems (energy systems) and industrial control. They meet IEC 60269‑2 and VDE requirements, making them suitable for all low-voltage protection needs.

• Ease of Maintenance: The double indicators simplify troubleshooting – operators don’t have to remove fuses to see which are blown. Combined with the NH fuse holder system, replacement is quick and safe (no live finger contacts required).

FAQ

double-indicator fuse?

The dual indicators make fault identification easier in complex panels. When any phase’s fuse blows, a flag will appear on that fuse at both ends, so you can see the blown fuse from either side of the busbar or door. This is especially useful in multi-pole switchgear.

Are double-indicator fuses otherwise different from single-indicator fuses？

Electrically, no. Both types have the same rated voltages, currents, and gG protection. The only difference is the indicator flags. All other characteristics (breaking capacity, materials, dimensions) match standard NH fuse specifications.