Mersen R642 Fuse Reducer – Class R – 600V – 400A to 600A Adapter (Fuse Clip Reducer)

The Mersen R642 is a Class R fuse reducer designed to allow 400A fuses to be used safely in 600A Class R fuse clips. It provides a secure mechanical and electrical interface that ensures correct alignment, reliable conductivity, and safe operation within industrial power distribution systems.

This reducer is used in retrofit applications and system standardization projects where existing high-amperage fuse holders must accommodate lower-rated fuses without modifying the equipment. The rejection-style design helps maintain safety by preventing improper fuse sizing and ensuring compliance with Class R protection systems.

Voltage and Rating

• Voltage Rating: 600V AC
• Fuse Class: Class R
• Current Compatibility: 400A to 600A
• Design Type: Fuse Reducer / Adapter

Key Specifications

• Product Type: Fuse Reducer Accessory
• Part Number: R642
• Manufacturer: Mersen
• Function: Adapts lower-rated fuses to higher-rated fuse clips
• Application Use: Class R fuse systems
• Unit Type: Each (EA)
• Design Style: Rejection-type safety fuse adapter

Technical Specifications

• Function: Ensures proper electrical and mechanical compatibility between fuse sizes
• Application Suitability: Industrial switchgear, motor control centers, and distribution panels
• Safety Feature: Rejection design prevents incorrect fuse installation
• System Integration: Designed for UL Class R fuse systems
• Installation Type: Clip-in fuse reducer insert

Physical Specifications

• Length: 69.8 mm
• Height: 50.8 mm

Standards and Approvals

• UL Listed for Class R fuse systems
• CSA Certified
• Designed for industrial electrical distribution compliance

Applications

• Industrial power distribution systems
• Motor control centers (MCCs)
• Switchgear assemblies
• Retrofit electrical installations
• Electrical system standardization
• Maintenance and upgrade projects
• Commercial and heavy industrial applications

Returns are easy

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

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