500 Volt Industrial Fuse-Links to IEC 60269-2 – Type LSPN/DIN

500V NH Industrial Fuse-Links with Knife Blade Contacts to IEC 60269-2 – Type LSPN/DIN NH Fuse | NH Fuse Links | NH Industrial Fuse Links | Knife Blade Fuse | DIN Type Fuse | HRC Fuse | Square Body Fuse | Single Indicator Fuse | NH Fuse Links Dual Indicator

Product Introduction

The Lawson Type LSPN/DIN is a comprehensive range of NH Fuse links — also known as NH Industrial Fuse Links or Knife Blade Fuse links — for use in 500V industrial electrical installations. As the most widely used high-current industrial fuse format in Europe and internationally, the NH Fuse system combines the mechanical robustness of a Square Body Fuse rectangular ceramic casing with flat metal blade-style knife contacts at each end, delivering a secure, low-resistance plug-in connection in NH fuse bases across the full range of industrial distribution and protection applications.

NH fuse-links are manufactured from a rectangular ceramic casing surrounded by a cover plate with a metal blade style terminal on each end. The fuse element inside the casing is connected to the cover plate and blade terminals. Lawson Fuses When a blown NH Fuse link needs replacement, it must always be replaced with a new fuse carrying the same electrical characteristics — the same NH size, current rating, voltage rating, and utilisation category.

Available in NH body sizes 000, 00, 0, 1, 2, and 3 — covering current ratings from 63A through to 630A — the Lawson Type LSPN/DIN DIN Type Fuse range includes standard gG general purpose variants as well as Single Indicator Fuse and NH Fuse Links Dual Indicator options for visual fault detection, plus motor circuit protection (gM) and semiconductor protection variants. Used in conjunction with the Lawson Type DFB NH Type Fuse Base range and the Lawson Type LUCH NH Universal Replacement Handle, the Type LSPN/DIN provides a complete, coordinated NH fuse system for industrial panel builders and switchgear manufacturers.

Key Features

• NH Fuse — the internationally dominant industrial HRC plug-in fuse format for high-current industrial protection
• NH Industrial Fuse Links with knife blade contacts — DIN-standardised blade contact design for secure, low-resistance insertion in NH fuse bases
• Knife Blade Fuse — flat metal blade terminals engage with spring-loaded contacts in the NH fuse base
• Square Body Fuse — rectangular ceramic body format, the internationally recognised NH fuse physical standard
• DIN Type Fuse — dimensionally standardised to DIN / IEC 60269-2 for compatibility with all DIN NH equipment
• HRC Fuse (High Rupturing Capacity) — 120kA breaking capacity for the highest industrial fault levels
• Available in NH sizes 000, 00, 0, 1, 2, and 3 — covering current ratings from 63A to 630A
• Rated 500V a.c. — suitable for 400V, 415V, and 500V three-phase industrial supply systems
• Single Indicator Fuse variants — single blown fuse indicator for visual fault detection on panel inspection
• NH Fuse Links Dual Indicator variants — dual indicator for detection from both sides of a panel assembly
• Motor circuit protection (gM) variants available — for DOL and star-delta motor starter applications
• Semiconductor protection variants available — Type LSPN/DIN also used for semiconductor device protection
• Used with Lawson Type DFB NH Fuse Bases and Type LUCH NH Universal Replacement Handle
• Compliant with IEC 60269-2 — the international standard for industrial fuse-links

Indicator Variants

Standard NH Fuse (no indicator) The standard NH Fuse links have no blown fuse indicator — suitable for applications where panel access for inspection is straightforward or where blown fuse detection is managed by other means (e.g. process monitoring or tripping signals).

Single Indicator Fuse The Single Indicator Fuse variant of the Type LSPN/DIN has a single visual indicator — typically a small striker pin or indicator button that projects from the fuse body when the fuse element has operated. This allows maintenance personnel to identify a blown NH Fuse during routine inspection or following a supply loss, without the need for electrical test equipment.

NH Fuse Links Dual Indicator The NH Fuse Links Dual Indicator variant provides blown fuse indication visible from both sides of the fuse body — making it particularly useful in busbar-mounted or back-to-back panel assemblies where access to only one face of the installed Knife Blade Fuse may be available. Dual indicator variants simplify fault finding in complex panel configurations.

Applications

The Lawson Type LSPN/DIN NH Fuse, NH Industrial Fuse Links, and DIN Type Fuse range is specified across the full spectrum of industrial and commercial high-current protection applications:

• Industrial distribution boards and MCCs — main and sub-main incoming supply fusing in motor control centres and primary distribution equipment
• Motor circuit protection — gM NH Fuse Links for DOL and star-delta motor starter incoming fusing
• Transformer primary and secondary protection — high breaking capacity HRC Fuse protection for distribution transformers
• Power factor correction equipment — capacitor bank protection using appropriately rated NH fuse-links
• Industrial switchgear and busbar chambers — Square Body Fuse links in three-phase DIN NH switchfuse assemblies
• Semiconductor protection — LSPN/DIN semiconductor variants for power converter, rectifier, and drive applications
• Renewable energy and power conversion — Knife Blade Fuse protection in large-scale inverter and converter equipment
• Heavy industry — steel works, chemical plant, mining, and process industries requiring robust high-current NH Fuse protection
• Railway and infrastructure — high-current distribution protection in depot, tunnel, and infrastructure traction power applications

Why Choose Lawson Type LSPN/DIN NH Fuse Links?

The NH fuse system is the dominant industrial HRC fuse format in Europe and across global industrial electrical infrastructure — and for good reason. The Square Body Fuse ceramic body combined with the Knife Blade Fuse plug-in contact system delivers breaking capacities of up to 120kA at 500V — far exceeding what is achievable with bolted-tag, cylindrical, or screw-cap fuse systems of equivalent current rating. This makes the NH Fuse the only practical choice for the main incoming and primary distribution circuits of large industrial installations where prospective fault currents are at their highest.

Type gG NH fuse-links are full range breaking capacity fuse-links used to protect cables and equipment. They can interrupt any current surge, from the lowest fusing current up to their breaking capacity, and can be used alone as protection. They also protect electrical devices and industrial set-ups from the electrodynamic effects of very high short-circuit currents. 

The Lawson Type LSPN/DIN DIN Type Fuse range — spanning sizes 000 through to 3 with gG, gM, semiconductor protection, and single and dual indicator variants — is manufactured under an ISO 9001 accredited quality management system with test facilities accredited to ISO/IEC 17025, and complies fully with IEC 60269-2.

The Lawson Type LSPN/DIN NH Fuse range covers six standard NH body sizes, each defined by its physical dimensions and rated current range:

xx denotes current rating in Amps. Full current rating schedules available in the Type LSPN/DIN Product Information Sheet.

Q1. What is an NH Fuse?

An NH Fuse (Niederspannungs-Hochleistungs-Sicherung, meaning low-voltage high-power fuse) is a high-rupturing-capacity industrial fuse-link characterised by its rectangular ceramic body (Square Body Fuse) and flat metal blade-style contacts (Knife Blade Fuse) on each end. NH fuse-links are manufactured from a rectangular ceramic casing surrounded by a cover plate with a metal blade style terminal on each end, with the fuse element inside the casing connected to the cover plate and blade terminals. The NH Fuse system is the most widely used industrial HRC fuse format in Europe and internationally, standardised under IEC 60269-2 and DIN standards.

Q2. What is a Knife Blade Fuse?

A Knife Blade Fuse is an NH fuse-link named after its distinctive flat, blade-shaped metal contacts on each end of the fuse body — as opposed to the round end-caps of cylindrical fuses or the threaded end-caps of Diazed and Neozed fuses. When an NH Fuse link is inserted into its fuse base using an NH fuse handle, the knife blade contacts engage with spring-loaded clips in the base, creating a firm, low-resistance connection that can withstand the mechanical and thermal stresses of high fault current interruption.

Q3. What is a DIN Type Fuse?

A DIN Type Fuse refers to an NH fuse-link conforming to the DIN (Deutsches Institut für Normung) dimensional standards for the NH fuse system — which are harmonised with IEC 60269-2 and used internationally. All Lawson Type LSPN/DIN NH Industrial Fuse Links are manufactured to DIN/IEC 60269-2 dimensional standards, ensuring compatibility with all DIN NH fuse bases, switches, and distribution equipment from any manufacturer conforming to the same standard.

Q4. What is the difference between NH Fuse sizes 000, 00, 0, 1, 2, and 3?

NH fuse sizes define the physical body dimensions of the Square Body Fuse and the maximum current rating each size can accommodate. Size 000 is the smallest (up to 63A), followed by Size 00 and Size 0 (up to 160A), Size 1 (up to 250A), Size 2 (up to 400A), and Size 3 (the largest, up to 630A). Importantly, NH fuse sizes are not interchangeable — a Knife Blade Fuse of one size will not fit a fuse base designed for a different size. Always confirm the NH size of the installed fuse base before ordering replacement NH Fuse Links.

Q5. What is a Single Indicator Fuse?

A Single Indicator Fuse is an NH Fuse link fitted with a visible blown fuse indicator — typically a small striker pin or indicator button that becomes visible on one face of the fuse body when the fuse element has operated. This allows maintenance personnel to quickly identify a blown Knife Blade Fuse during panel inspection without needing test equipment, significantly reducing fault diagnosis time and downtime.

Q6. What are NH Fuse Links Dual Indicator?

NH Fuse Links Dual Indicator are NH Industrial Fuse Links fitted with a blown fuse indicator visible from both sides of the fuse body. This is particularly useful in busbar-mounted assemblies, back-to-back panel configurations, or any installation where only one face of the fuse base may be accessible for inspection. Dual indicator variants make fault identification faster and safer in complex industrial panel environments.

Q7. What is an HRC Fuse and how does it relate to NH Fuses?

An HRC Fuse (High Rupturing Capacity Fuse) is a general term for any fuse-link capable of safely interrupting very high fault currents — typically above 50kA. The NH Fuse is the most common industrial HRC fuse format, with breaking capacities of up to 120kA at 500V a.c. The ceramic body and quartz sand fill of the NH Square Body Fuse are specifically engineered to absorb and extinguish the arc energy generated during high fault current interruption, preventing explosive failure or arc flashover to adjacent components.

Q8. What is the difference between gG and gM NH Fuse Links?

A gG NH Fuse provides full-range general purpose overcurrent protection — protecting cables and equipment against both overload currents and short-circuit currents across the complete current range. A gM NH Fuse Link is a motor circuit protection variant that tolerates the short-duration starting inrush current of DOL or star-delta motor starters without nuisance operation, while still providing full overcurrent protection. For motor circuit applications, the gM variant should be specified; for general cable and sub-circuit protection, the gG variant is appropriate.

Q9. What semiconductor protection variants are available in the LSPN/DIN range?

The Type LSPN/DIN range includes semiconductor protection variants specifically designed for the protection of power semiconductor devices — including thyristors, diodes, IGBTs, and rectifier bridges — within the NH knife blade fuse format. These variants have fast-acting operating characteristics matched to the I²t withstand ratings of semiconductor devices, providing ultra-fast fault current interruption before semiconductor damage can occur. Contact the Lawson Fuses sales team for details of available semiconductor protection ratings and sizes.

Q10. What fuse handle and fuse base are required for the Lawson Type LSPN/DIN NH Fuse?

The Lawson Type LSPN/DIN NH Fuse Links are designed to be used with the Lawson Type DFB NH Fuse Base (available in sizes 00, 1, 2, and 3) and the Lawson Type LUCH NH Universal Replacement Handle, which is used to safely insert and extract Knife Blade Fuse links from energised or de-energised NH fuse bases. The NH fuse base size must match the NH fuse-link body size being installed. Contact the Lawson Fuses sales team for a complete Type LSPN/DIN DIN Type Fuse system specification.