Overview
The Gould Shawmut OT40 is a general-purpose one-time fuse rated 40 amperes at 250 volts, Class K5 fast-acting classification. Manufactured by Ferraz Shawmut (now Mersen), this cartridge-style fuse delivers low-cost circuit protection for feeder and branch circuits serving lighting, heating, and non-motor loads in industrial and commercial electrical systems. With a 50,000-ampere interrupt rating, the OT40 safely clears short-circuit faults across its entire voltage and amperage range, making it a reliable choice for equipment protection and system uptime.
Key Features
- Fast-acting (one-time) fuse design—no time delay; suitable for non-motor circuits
- 50,000-ampere interrupt rating for safe short-circuit interruption
- Class K5 rating ensures compatibility with Class K-rated fuseholders and switchgear
- UL and CSA listed for industrial use in North America
- Compact cartridge form factor; standard installation in fuse blocks and switch disconnects
- Lot of 6 units—ready inventory for maintenance stocking
Technical Specifications
Ampere Rating: 40A
Voltage Rating: 250 Vac, 250 Vdc
Speed Type: Fast-Acting
Classification: Class K5
Interrupt Rating: 50,000A AC
Form Factor: Cartridge Fuse
Certifications: UL, CSA, RoHS
Configuration: Lot of 6 units
Typical Applications
- Feeder and branch circuit protection in industrial panels and switchboards
- Lighting and heating load circuits (non-motor applications)
- General-purpose electrical distribution systems
- Equipment protection in manufacturing and facility maintenance
- Backup and spare fuse inventory for critical systems
Compatibility & Replacements
Compatible With
- Class K-rated fuseholder and clip assemblies
- Industrial disconnect switches and fused load centers
- Power distribution panels rated 250V AC/DC
- Standard cartridge fuse form factor holders
- UL/CSA-listed electrical enclosures and switchgear
Replaces / Drop-In Replacement For
- Eaton Cooper Bussmann NON-40, Reliance 64676-K, Littelfuse NLN040
- Legacy Gould fuse applications; Ferraz Shawmut is current manufacturer under Mersen
- Any OT-series 40A Class K5 one-time fuse requirement
Works With
- Class K-rated fuse clips and cartridge holders
- Industrial switchgear and load-center installations
- Manual and automatic disconnect switches
- Power monitoring and circuit protection systems
