Overview
The Gould Shawmut OT20 is a reliable one-time (fast-acting) general-purpose fuse rated 250V AC/DC at 20 amps. Belonging to the Class K5 fuse family, the OT20 delivers robust short-circuit protection with a 50,000-ampere interrupting capacity, making it suitable for feeder and branch circuits serving lighting, heating, and non-motor loads in industrial, commercial, and residential applications.
Key Features
- 250V AC/DC Rating — Safe operation across standard low-voltage industrial circuits
- 20A Current Rating — Precise protection for specified circuit amperage
- 50 kA Interrupting Rating — Reliably interrupts available short-circuit currents up to 50,000 amperes
- Class K5 Fast-Acting — One-time construction responds quickly to overload conditions
- Non-Rejection Design — Straightforward replacement without mechanical rejection mechanisms
- UL/CSA Approved — Meets North American electrical standards and codes
- Box of 10 — Convenient quantity for maintenance and replacement stock
Technical Specifications
| Voltage Rating | 250V AC / 250V DC |
| Ampere Rating | 20A |
| Fuse Class | K5 |
| Type | One-Time (Fast-Acting) |
| Interrupting Rating | 50,000A (50 kA) |
| Shape | Cartridge (Ferrule) |
| Manufacturer | Gould / Ferraz Shawmut (now Mersen) |
| Approvals | UL, CSA, RoHS |
| Quantity per Box | 10 |
| Part Number | OT20 |
Typical Applications
- Branch circuits for lighting and heating equipment
- General-purpose feeder protection in industrial plants and commercial buildings
- Low-voltage power distribution circuits
- Equipment requiring non-time-delay (fast-acting) overcurrent protection
- Replacement stock for maintenance technicians and system integrators
Compatibility & Replacements
Compatible With
- Any 250V AC/DC electrical circuit rated for 20A cartridge fuses
- Standard ferrule-type fuse holders and fusible disconnect switches
- Industrial control panels and switchboards
- Low-voltage motor control equipment (non-motor load applications)
Replaces / Drop-In Replacement For
- Eaton Cooper Bussmann NON-20
- Bussmann 203 64676-F 12402
- Littelfuse NLN020
- Original Gould Shawmut OT20 units
Works With
- NEMA-rated industrial control systems
- IEC-compliant low-voltage installations
- Standard 250V AC power distribution infrastructure
- Both legacy Gould Shawmut and modern Mersen electrical equipment
