Mersen R422 Fuse Reducer – Class R – 200A–400A – 600V Rejection-Type Fuse Adapter (Ferraz Shawmut)

The Mersen R422 is a Class R rejection-type fuse reducer designed to allow 200A fuses to be used safely in 400A Class R fuse clips. It ensures proper mechanical fit, electrical alignment, and code-compliant operation when adapting fuse sizes within existing high-capacity fuse holders. This makes it a practical solution for retrofits, equipment standardization, and reducing inventory complexity in industrial power distribution systems.

Class R reducers like the R422 are engineered with rejection features so only compatible Class R fuses can be installed, preventing unsafe fuse substitution and maintaining system protection integrity.

Voltage and Rating

• Voltage Rating: 600V AC
• Fuse Class: Class R
• Current Compatibility: 200A fuse in 400A fuse clips
• Type: Rejection-style fuse reducer

Key Specifications

• Product Type: Fuse Reducer / Fuse Clip Accessory
• Part Number: R422
• Manufacturer: Mersen
• Alternate Mfr Part Number: W219600
• Application Use: Class R fuse systems
• Unit Type: Each (EA)
• Design Type: Rejection fuse adapter (safety-interlocked sizing)

Technical Specifications

• Function: Allows lower-rated fuse installation in higher-rated fuse holders while maintaining proper protection coordination
• Safety Feature: Rejection design prevents incorrect fuse class or oversizing
• Application Suitability: Industrial control panels, motor control centers, and distribution systems
• System Integration: Designed specifically for UL Class R fuse systems
• Installation: Insert-style accessory used within existing fuse clips

Standards and Approvals

• UL Listed (Class R fuse systems)
• CSA Certified
• Industrial electrical accessory compliance for fuse coordination systems

Applications

• Industrial power distribution panels
• Motor control centers (MCCs)
• Retrofit electrical installations
• Equipment standardization projects
• Maintenance and fuse system upgrades

Returns are easy

You may return items within 30 days of delivery for a refund.

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