Overview
The Shawmut TR1/2R 0.5A fuse is a Tri-Onic time-delay cartridge fuse designed for overcurrent protection in motor, transformer, and branch-circuit applications. Each box contains 9 new, unboxed units rated for 250Vac with a 200kA interrupt rating. The time-delay characteristic allows harmless starting currents and inrush loads to pass without nuisance trips, making it ideal for equipment with high initial draw demands.
Key Features
- Time-delay (dual-element) design safely handles motor starting currents and transformer inrush
- Class RK5 current-limiting fuse for fast, predictable protection
- 250Vac voltage rating with 200,000A interrupt capacity
- Cartridge style (0.56″ diameter × 2″ length) fits standard fuse holders
- UL and CSA approved for industrial and commercial use
- Compatible with Mersen (Ferraz Shawmut) TR series ecosystems
Technical Specifications
- Ampere Rating: 0.5A (1/2A)
- Voltage Rating (AC): 250Vac
- Interrupt Rating: 200 kA @ 250Vac
- Speed: Time Delay
- Class: RK5 (current-limiting)
- Shape: Cartridge
- Dimensions: 0.56″ Diameter × 2″ Length (14.2 × 50.8 mm)
- Weight: 0.8 oz per fuse
- Approvals: UL, CSA, RoHS
- Package Quantity: 9 fuses per box
Typical Applications
- Motor circuit protection and supplemental fuses
- Transformer protection in control circuits
- Service entrance and feeder equipment protection
- Industrial machinery and equipment branch circuits
- HVAC systems and compressor circuits
- Not suitable for main branch-circuit protection; use for supplemental/equipment protection
Compatibility & Replacements
Compatible With
- Standard cartridge fuse holders and blocks rated for TR series fuses
- Motor control centers (MCCs) with 250Vac, Class RK5 fuse positions
- Transformer protection circuits in industrial control systems
- Equipment designed for Mersen (Ferraz Shawmut) TR-R series fuses
- Any 250Vac circuit rated for time-delay, Class RK5 protection
Replaces / Drop-In Replacement For
- Mersen TR1/2R (identical product — Ferraz Shawmut is now Mersen)
- Gould Shawmut TR1/2R (legacy brand designation)
- Equivalent 0.5A, 250Vac, Class RK5 time-delay cartridge fuses from compatible suppliers
Works With
- Rockwell/Allen-Bradley motor starters and MCCs with RK5 fuse positions
- Siemens SIRIUS motor starter and control equipment
- GE Industrial Solutions control circuits
- Schneider Electric motor protection schemes
- Any industrial control system using standard cartridge fuse architecture
- Power factor correction panels and capacitor banks (where applicable)
