Overview
The Bussmann 663-R Class R fuse reducer is a critical component for adapting smaller fuses to larger-capacity fuse clips. This reducer installs in fuse clips to permit the installation of smaller size fuses than those for which the clips are designed, providing flexible circuit protection in control panels, disconnect switches, and distribution equipment. Supplied as a pair per carton, the 663-R handles up to 30A fuses in 60A equipment slots.
Key Features
- Makes 30A/600V fuses fit 60A clips
- CSA and UL certified for code compliance
- Maintains strong contact both mechanically and electrically
- Compact design for use in dead-front panels and enclosed switches
- Industry-standard Class R fuse reducer from trusted Bussmann brand
Technical Specifications
- Part Number: 663-R (also labeled NO.663-R)
- Voltage: 600V AC
- Fuse Size: Up to 30A
- Equipment Clip Size: 60A
- Fuse Class: Class R
- Package Quantity: 1 pair
- Standards: UL, CSA
- Manufacturer: Bussmann (Cooper Industries)
Typical Applications
Class R fuse reducers like the 663-R are used in:
- Industrial control panels and machinery disconnect switches
- Motor control centers and starter enclosures
- Electrical distribution and sub-panel installations
- Any equipment requiring downsizing from 60A to 30A fuse protection
- Retrofit upgrades where fuse block sizing must be preserved
Compatibility & Replacements
Compatible With
- Bussmann FRS-R (Fusetron) 30A Class RK5 fuses
- Bussmann LPS-R (class R) cartridge fuses up to 30A
- All Class R dimension fuses rated 30A or less
- Standard 60A fuse clips and equipment fuse blocks
- Panel-mount and switch-mount fuse holders
Replaces / Drop-In Replacement For
The 663-R is a direct replacement for other Bussmann 663-R units. Verify part compatibility with your equipment manufacturer to ensure the fuse block is designed for reducer use. Not interchangeable with other voltage ratings (250V uses 263-R instead) or different fuse classes.
Works With
- Bussmann Fusetron and Limitron fuse series
- Cooper Bussmann fuse blocks and clips rated 60A
- Eaton/Bussmann electrical distribution products
- Standard industrial control and electrical panels
- Class R fuse-based circuit protection systems
