Overview
The Shawmut OT40 40A fuse is a Class K5 general-purpose, one-time cartridge fuse designed to protect electrical circuits from overload and short-circuit conditions. Mersen OT One-Time general purpose fuses provide low cost protection for feeder and branch-circuits serving lighting, heating, and other non-motor loads. OT fuses will safely interrupt available short-circuit currents up to 50,000 amperes in all ratings. This box contains 10 units, all manufactured to original Gould/Shawmut (now Mersen/Ferraz) specifications.
Key Features
- Class K5 Rating: Meets UL 248-9 and CSA C22.2 standards for reliable performance and safety certification
- One-Time Operation: Non-renewable fuse that permanently opens when rated current is exceeded; no resetting required
- High Interrupting Rating: OT40 fuses will safely interrupt available short circuit currents up to 50,000 amperes in all ratings.
- Ferrule Terminals: Ferrule Terminal with Diameter 13/16 Inch and Length 3 Inch for secure, standard cartridge-style installation
- Dual Voltage Rating: Rated for both 250VAC and 250VDC applications
- Box of 10: Economical packaging for maintenance stock and system upgrades
Technical Specifications
- Amperage Rating: 40A
- Voltage Rating: 250VAC / 250VDC
- Interrupting Rating: 50,000 amperes
- Fuse Class: Class K5
- Type: One-Time (Non-Renewable)
- Terminal Style: Ferrule
- Length: 3 inches
- Diameter: 13/16 inch
- Approvals: UL 248-9, CSA C22.2
- Packaging: Box of 10 units
- Manufacturer: Gould/Shawmut (Mersen/Ferraz)
Typical Applications
The Shawmut OT40 40A fuse is suitable for:
- Feeder Circuits: Primary protection in main distribution panels and subfeed lines
- Branch Circuits: Protection for lighting, heating, and general non-motor loads
- Industrial Control: Equipment protection in machinery starter circuits and control panels
- HVAC Systems: Furnaces, air handlers, and heating/cooling unit protection
- Electrical Maintenance: Replacement stock for existing systems using Class K5 cartridge fuses
Compatibility & Replacements
Compatible With
- Standard 1-13/16″ × 13/16″ cartridge fuse holders and blocks rated for 250V service
- Electrical panels, disconnect switches, and motor control centers with Class K fuse accommodation
- Industrial control systems and power distribution equipment designed for Class K5 protection
Replaces / Drop-In Replacement For
- Ferraz Shawmut OT40 is comparable to Eaton Cooper Bussmann NON-40, Reliance 64676-K, Littelfuse NLN040.
Works With
- Mersen OT Series: Compatible with other OT-rated cartridge fuses in different amperage ratings (15A through 100A)
- UL/CSA Certified Equipment: Any electrical distribution equipment requiring Class K5 one-time fuse protection
- Voltage Compatibility: Works in 250VAC industrial circuits and 250VDC DC power applications
