Overview
The Ferraz Shawmut A480R6R-1HE (now Mersen-branded) is an industrial-grade, R-Rated current-limiting fuse rated for 170A at 4800V AC. This medium voltage fuse delivers 65 kA interrupting capacity and is designed specifically for short-circuit protection of medium voltage motors and motor control centers. The A480R6R-1HE features a single-barrel ferrule-mount design with spring-reinforced clips, making it a reliable drop-in replacement for older Gould and Ferraz Shawmut installations.
Key Features
- Current-limiting design: Reduces fault current and minimizes equipment damage during short circuits
- R-Rated fuse class: Back-up protection requiring coordination with overload relays in motor starters (per motor starter manufacturer specifications)
- Dual voltage compatibility: Rated for both 2400V and 4800V AC, 50/60 Hz operation
- Ferrule-mount terminals: Spring-reinforced clip mounting for secure installation
- Amp-Trap® construction: Time-tested design from Ferraz Shawmut (now Mersen)
- High interrupting capacity: 65 kA @ 4800V ensures coordination with upstream protective devices
Technical Specifications
- Amperage (R-Rating): 6R (170A)
- Voltage: 2400V / 4800V AC
- Frequency: 50/60 Hz
- Interrupting Capacity: 65 kA @ 4.8 kV
- Fuse Class: R (Back-up / Motor)
- Barrel Diameter: 3 inches (Size D)
- Overall Length: 15.97 inches (410 mm)
- Mounting: Ferrule terminals, spring-reinforced clips
- Weight: Approximately 10.48 lbs
- Indication: Indicating fuse (visible blown fuse)
Typical Applications
- Medium voltage motor short-circuit protection (1–3 MW motors)
- Motor controller backup protection in combination starters
- Industrial switchgear and motor control centers
- Utility and industrial power distribution systems
- Oil and gas, mining, water treatment, and manufacturing environments
Compatibility & Replacements
Compatible With
- Ferraz Shawmut / Mersen medium voltage fuse holders and clips (3 inch Size D barrel)
- Motor control centers and starters requiring R-Rated backup fuses
- Industrial switchgear rated for 4800V and 2400V distribution
- Spring-reinforced ferrule-mount fuse clips
Replaces / Drop-In Replacement For
- Gould Shawmut A480R6R-1 (legacy non-HE variant)
- Ferraz Shawmut A480R6R-1 (earlier production)
- Mersen A480R6R-1 (current manufacturer designation)
Works With
- Overload relays in NEMA motor starters
- IEC combination motor starters
- Medium voltage switchgear and soft starters (when properly coordinated)
- ANSI C37.46 and IEEE C37.41 standard protective schemes
