400/500/690 Volt Cylindrical Fuse-links to IEC 60269 2 IEC 60269 3 – Type LFN

400/500/690V Cylindrical Fuse Links to IEC 60269-2 & IEC 60269-3 – Type LFN Cylindrical Fuse Links | gG Cylindrical Fuse | Motor Protection gM Fuse | 10×38 Fuse | 14×51 Fuse | 22×58 Fuse

Product Introduction

The Lawson Type LFN is a comprehensive range of Cylindrical Fuse Links designed for general purpose overload and short-circuit protection across 400V, 500V, and 690V industrial electrical installations. As a certified gG Cylindrical Fuse (general purpose, full-range protection) and gM motor protection variant, the Type LFN covers four standard cylindrical fuse body sizes — 8x31mm, 10×38 Fuse, 14×51 Fuse, and 22×58 Fuse — in a complete range of current ratings from 1A to 125A.

Fully compliant with IEC 60269-2 and IEC 60269-3, the Lawson Type LFN Cylindrical Fuse Links feature ceramic bodies and silver-plated contacts for superior conductivity and long-term reliability. The gG range provides primary protection against overloads and short circuits in industrial sub-circuits, control panels, and distribution equipment. For motor circuit applications, the gM variant (replace ‘G’ with ‘M’ in the list reference — e.g. LFN10G becomes LFN10M) provides motor starting current tolerance alongside overcurrent protection. A range of semiconductor protection fuse-links is also available.

Designed to work in direct combination with the Lawson Type MS Modular Cylindrical Fuse-Holder range, the Type LFN Cylindrical Fuse Links are the natural fuse-link solution for any panel builder or electrical engineer specifying Lawson Type MS DIN Rail Fuse Holders.

Key Features

• Cylindrical Fuse Links to IEC 60269-2 and IEC 60269-3 — internationally certified industrial fuse-link standard
• gG Cylindrical Fuse — full-range general purpose protection against overloads and short-circuit currents
• gM Motor Protection variants — replace ‘G’ with ‘M’ in list reference for motor circuit protection
• Ceramic body construction — withstands large internal pressure and thermal shocks under fault conditions
• Silver-plated contacts — low contact resistance and excellent long-term conductivity
• Four standard body sizes: 8x31mm, 10x38mm (10×38 Fuse), 14x51mm (14×51 Fuse / 14×52 Fuse), 22x58mm (22×58 Fuse)
• Rated voltages: 400V, 500V, and 690V a.c. — covering the full range of industrial three-phase supply voltages
• Current ratings from 1A to 125A — comprehensive coverage of industrial sub-circuit protection requirements
• Compatible with Lawson Type MS Modular Cylindrical Fuse-Holders (MSC 81, MSC 101, MSC 141, MSC 221)
• Semiconductor protection fuse-links also available in the LFN range
• Solid/neutral links (SLLFN series) available for all frame sizes

LFN 10G / LFN 10M — 10×38 Fuse (10mm x 38mm)

The 10×38 Fuse (LFN 10G / LFN 10M) is the most widely used cylindrical fuse-link size in industrial control panels throughout the UK and Europe. The gG general purpose range (LFN 10G) is available in a comprehensive set of current ratings — including 1A, 2A, 4A, 6A, 8A, 10A, 12A, 16A, 20A, 25A, and 32A — providing precise sub-circuit overcurrent protection across the full range of standard industrial three-phase branch circuit current ratings. The gM motor protection variant (LFN 10M) accommodates motor starting current surges without nuisance operation, available in equivalent ratings.

LFN 14G / LFN 14M — 14×51 Fuse (14mm x 51mm)

The 14×51 Fuse (also referenced as 14×52 Fuse) in the LFN 14G / LFN 14M range is used for mid-range current protection from sub-circuit level up to 50A. Suited to transformer primary fusing, higher-rated motor circuit protection, and feeder circuit applications in industrial panels and distribution boards. The gG general purpose (LFN 14G) and gM motor protection (LFN 14M) variants cover the current ratings up to 50A, matching the Lawson MSC 141 fuse holder.

LFN 22G / LFN 22M — 22×58 Fuse (22mm x 58mm)

The 22×58 Fuse (LFN 22G / LFN 22M) is the largest cylindrical fuse format in the Type LFN range, covering high-current applications up to 125A. The gG general purpose (LFN 22G) range includes ratings of 63A, 80A, 100A, and 125A for use in main incomer fusing, busbar sub-circuit protection, and high-current distribution applications. Motor protection variants (LFN 22M) are available for larger motor circuit applications. Both types match the Lawson MSC 221 fuse holder.

gG vs gM — Choosing the Right Cylindrical Fuse

gG Cylindrical Fuse (LFN xG series) The gG Cylindrical Fuse provides full-range general purpose overcurrent protection — operating on both overload currents and short-circuit currents. It is the standard choice for the protection of cables, conductors, and general sub-circuit equipment where no significant inrush current is expected. To select a gM fuse-link from the Lawson LFN range, simply replace ‘G’ with ‘M’ in the list reference (e.g. LFN10G16 becomes LFN10M16).

gM Motor Protection Cylindrical Fuse (LFN xM series) The gM motor protection cylindrical fuse is a dual-rated fuse-link that tolerates the short-duration inrush current of direct-on-line or star-delta motor starting without nuisance operation, while still providing full overcurrent protection under sustained fault or overload conditions. The gM variant is essential where the motor starting current would cause a standard gG fuse to operate during normal starting.

Applications

The Lawson Type LFN Cylindrical Fuse Links range is specified across a wide range of industrial and commercial applications:

• Industrial control panel sub-circuit protection — the LFN 10G 10×38 Fuse is the standard fuse-link for three-phase sub-circuit protection in industrial MCCs, control panels, and switchgear
• Motor circuit protection — gM variants (LFN 10M, LFN 14M, LFN 22M) for direct-on-line and star-delta motor starter fusing
• Transformer primary protection — LFN 14G and LFN 22G for transformer primary side fusing
• Distribution board feeder fusing — LFN 22G 22×58 Fuse for high-current feeder and incomer protection
• Machine tool and automation panels — compact cylindrical fuse protection for multi-axis CNC and robotic equipment
• Building services and HVAC — sub-circuit and control circuit fusing in BMS and mechanical services panels
• Marine and offshore — 690V rated LFN variants for shipboard and offshore platform electrical systems
• Railway and rolling stock — control and auxiliary circuit protection in traction and on-board equipment
• Renewable energy — LFN cylindrical fuse-links for solar, wind, and energy storage system panel protection

Why Choose Lawson Type LFN Cylindrical Fuse Links?

The Lawson Type LFN Cylindrical Fuse Links range offers a combination of ceramic body construction, silver-plated contacts, multi-voltage ratings (400V, 500V, 690V), gG and gM utilisation categories, and the full IEC 60269 standard body size range — in a single, coherent product family that integrates directly with the Lawson Type MS Modular Cylindrical Fuse-Holder range for a fully coordinated fuse and holder system.

Manufactured by Lawson Fuses under an ISO 9001 accredited quality management system with test facilities independently accredited to ISO/IEC 17025, and compliant with both IEC 60269-2 and IEC 60269-3, the Type LFN is the Cylindrical Fuse Links choice that electrical engineers, panel builders, and maintenance teams across the UK and internationally trust for reliable, certified industrial overcurrent protection.

Q1. What are Cylindrical Fuse Links?

Cylindrical Fuse Links are barrel-shaped cartridge HRC fuse-links used in industrial and commercial electrical protection. They have a ceramic or glass cylindrical body with metal end caps (ferrules) and are installed in modular cylindrical fuse holders mounted on a DIN rail. The Lawson Type LFN is a range of gG Cylindrical Fuse links covering four standard body sizes — 8x31mm, 10x38mm, 14x51mm, and 22x58mm — rated at 400V, 500V, and 690V a.c. for use in industrial control panels, distribution boards, and switchgear.

Q2. What is the difference between gG and gM cylindrical fuse links?

A gG Cylindrical Fuse (general purpose, full-range) provides protection against both overload currents and short-circuit currents and is the standard choice for cable and sub-circuit protection. A gM cylindrical fuse-link is a motor circuit protection fuse with a dual rating — it can withstand the short-duration high inrush current of motor starting without operating, while still protecting the circuit against sustained overloads and short circuits. In the Lawson LFN range, gM variants are selected by replacing ‘G’ with ‘M’ in the list reference — for example, LFN10G16 (gG, 16A) becomes LFN10M16 (gM, 16A).

Q3. What is a 10×38 Fuse and what current ratings are available?

A 10×38 Fuse is a cylindrical fuse-link measuring 10mm in diameter and 38mm in length — the most widely used cylindrical fuse size in industrial control panels. The Lawson LFN 10G range covers current ratings of 1A, 2A, 4A, 6A, 8A, 10A, 12A, 16A, 20A, 25A, and 32A in the gG general purpose category, with gM motor protection variants also available across the same current range. The LFN 10G / LFN 10M is compatible with the Lawson MSC 101 modular fuse holder (32A rated).

Q4. What is a 14×51 Fuse (14×52 Fuse) and when is it used?

The 14×51 Fuse (also referenced as 14×52 Fuse) is a cylindrical fuse-link measuring 14mm in diameter and 51mm in length — a larger format used for mid-range current protection up to 50A. The Lawson LFN 14G (gG) and LFN 14M (gM) are used for sub-circuit protection, transformer primary fusing, and motor circuit applications at higher current ratings than the 10×38 format. The LFN 14G / LFN 14M is compatible with the Lawson MSC 141 modular fuse holder (50A rated).

Q5. What is a 22×58 Fuse and what applications does it cover?

The 22×58 Fuse is the largest cylindrical fuse-link format in the Lawson LFN range, measuring 22mm in diameter and 58mm in length, rated up to 125A. The LFN 22G (gG) range includes ratings of 63A, 80A, 100A, and 125A for use in high-current main distribution, incomer protection, and busbar sub-circuit fusing. Motor protection variants (LFN 22M) are available for larger motor circuit applications. The LFN 22G / LFN 22M is compatible with the Lawson MSC 221 modular fuse holder (125A rated).

Q6. What voltage ratings are available for the Lawson LFN Cylindrical Fuse Links?

The Lawson Type LFN Cylindrical Fuse Links are rated for use at 400V, 500V, and 690V a.c. — covering standard UK and European industrial three-phase supply voltages. The 690V rating makes the LFN range suitable for demanding industrial environments including offshore, marine, and heavy industrial applications where higher supply voltages are used.

Q7. Why do Cylindrical Fuse Links have ceramic bodies?

Ceramic bodies are used in industrial Cylindrical Fuse Links because ceramic can withstand the extreme internal pressures and thermal shocks generated when the fuse-link operates under high fault current conditions. Ceramic also provides excellent electrical insulation and is chemically resistant to the arc products generated during fuse operation — ensuring a safe, contained interruption without risk of body fragmentation or arc flashover to adjacent components.

Q8. What are silver-plated contacts and why do they matter?

Silver-plated contacts (also called silver-plated ferrules) on Cylindrical Fuse Links provide a low-resistance, corrosion-resistant contact surface between the fuse-link and the fuse holder clips. Silver has excellent electrical conductivity and resists oxidation over time — ensuring that the contact resistance between fuse and holder remains low and consistent throughout the service life of the installation. High contact resistance can cause localised heating and power loss, so silver-plated contacts are important for reliable performance in industrial applications.

Q9. How do I select the correct Cylindrical Fuse Link for my application?

Selecting the correct Cylindrical Fuse Links requires matching four key parameters: the body size (8.5×31.5, 10×38, 14×51, or 22x58mm) to the fuse holder installed; the voltage rating (400V, 500V, or 690V) to the supply; the current rating to the circuit design current; and the utilisation category (gG for general purpose or gM for motor circuit protection) to the load type. For gM motor circuit selection, the motor full-load current and starting current ratio must also be considered.

Q10. Are solid/neutral links available to complement the LFN range?

Yes. Lawson supplies solid/neutral links (SLLFN series) for all four body sizes in the Type LFN range — SLLFN 820 (8x31mm, 20A), SLLFN 10 32 (10x38mm, 32A), SLLFN 14 50 (14x51mm, 50A), and SLLFN 22 125 (22x58mm, 125A). Solid links are used in place of fuse-links in the neutral conductor of three-phase or four-wire circuits where overcurrent protection of the neutral is not required but a secure, reliable neutral connection is still needed within the fuse holder assembly.