Lawson Type LSPN Dual Indicator fuse-links are 500V AC NH industrial fuse-links manufactured to IEC 60269-2. Designed for use in industrial switchgear, distribution boards and panel assemblies, they provide reliable overload and short-circuit protection in demanding installations.
The defining feature of the LSPN Dual Indicator is its two built-in visual trip indicators — one fitted at each end of the fuse body. When the fuse element operates, spring-loaded flags pop out from both ends simultaneously. This means the blown condition is immediately visible from either side of a switchgear panel or fuse block — eliminating the need to remove the fuse to confirm whether it has operated. In multi-phase or hard-to-access installations, this can significantly reduce maintenance time and the risk of accidental live-contact.
Available in sizes NH000, NH00, NH1, NH2, NH2C and NH3, covering current ratings from 16A to 630A, the LSPN Dual Indicator range is suitable for general industrial protection (gG characteristic) as well as semiconductor and motor circuit applications. The rectangular ceramic body with metal knife-blade contacts is designed to fit Lawson DFB fuse bases and standard NH-format fusegear.
Manufactured at Lawson’s UK facility in Newcastle upon Tyne, these fuse-links are supplied with full technical documentation and are available through Lawson’s network of authorised UK wholesalers.
Key Features & Benefits
- Dual visual indicator: Spring-loaded trip flags at both ends — blown fuse visible from either side of the panel without removal
- Five NH sizes: NH000, NH00, NH1, NH2, NH2C and NH3 covering 16A–630A
- 500V AC rated: To IEC 60269-2; 80kA high breaking capacity (HBC)
- Knife-blade contacts: Fits Lawson DFB fuse bases and all standard NH-format holders and switch-disconnectors
- gG characteristic: Full-range protection for cables and general industrial circuits; suitable for semiconductor and motor circuit coordination
- Ceramic body construction: High-strength porcelain tube filled with silica sand for safe arc extinction and fault energy containment
- UK manufactured: Made at Lawson Fuses’ Newcastle facility; ISO 9001 quality management
- ASTA 20 certified: Independent third-party certification to breaking capacity requirements of IEC 60269-2
Typical Applications
LSPN Dual Indicator NH fuse-links are suited to a wide range of 500V industrial protection duties:
- Industrial switchgear and distribution boards where quick blown-fuse identification is required
- Main and sub-distribution feeder circuits in factories, process plant and commercial buildings
- Motor control centres and motor circuit feeders (in coordination with overload relays)
- Semiconductor protection circuits — thyristors, diodes and power converters — where fast-acting, high-breaking-capacity protection is needed
- Panel builder assemblies using standard NH-format fuse switch-disconnectors
- Retrofit and replacement in existing NH fusegear across all standard sizes NH000–NH3
- Any installation where maintenance personnel need to identify a blown fuse without de-energising or removing the fuse from a live panel
How the Dual Indicator Works
Standard NH fuse-links carry a single trip indicator — a spring-loaded pin or flag fitted to one end of the fuse body. When the fuse element melts under a fault condition, the indicator pops out, providing a visible signal that the fuse has operated.
The LSPN Dual Indicator improves on this by incorporating trip indicators at both ends. When the fuse element operates, both flags deploy simultaneously. This has a practical advantage in multi-phase panel assemblies and busbar installations: maintenance engineers can identify which fuses have blown from either side of a mounting assembly or enclosure — without opening doors, rotating fuse blocks, or removing the fuse-link under energised conditions.
In substations, motor control centres and industrial switchboards where space is restricted and access is from alternating sides, the dual indicator design can make a meaningful difference to maintenance speed and safety.
The LSPN Dual Indicator should not be confused with the LSPN/DIN (single indicator) range, which carries one indicator only. Both ranges share the same 500V NH ceramic body format and are compatible with Lawson DFB fuse bases and LUCH fuse handles.
