Eaton 3MFS400RT - 400A, 120/240V, Fuse Switch

The Eaton 3MFS400RT is a rugged 400A fuse switch designed to deliver reliable on/off isolation and precise overcurrent protection in demanding industrial and commercial environments. Built to stand up to demanding duty, this switch provides a clear, hands-on method to disconnect power and protect critical circuits when it matters most.

Key advantages

• 400 Ampere rating supports high-load applications, including motor circuits and heavy equipment feeds.
• 120/240V operation fits common US electrical systems, enabling straightforward integration into existing panel layouts.
• On/off isolation provides a simple, secure way to de-energize systems for maintenance, service, or emergency shutdowns.
• Overcurrent protection helps shield wiring and equipment from short circuits and overloads, reducing downtime and repair costs.
• Compact, maintainable design is ideal for panelboards and spaces where space is at a premium, without sacrificing accessibility or serviceability.
• Versatile for industrial and commercial use—well-suited for motor disconnects, branch circuit protection, and panelboard integration where a robust fusible switch is required.

Ideal use cases

• Motor disconnects in manufacturing lines, pumps, conveyors, and HVAC drives where rapid isolation is essential for maintenance and safety.
• Panelboard installations that require a compact, maintainable switching solution with built-in protection.
• Branch circuit protection in commercial facilities, processing plants, and light industrial environments needing dependable performance.

Specifications at a glance

• Model: 3MFS400RT
• Amperage: 400A
• Voltage: 120/240V

Why choose this fuse switch

The Eaton 3MFS400RT stands out through its combination of high-current capability and practical, space-conscious design. It’s built to endure industrial use, offering dependable power isolation when technicians need to service equipment or perform routine maintenance. By integrating seamlessly with panelboards and branch circuits, it helps streamline electrical protection strategies, making it easier to manage risk, reduce unplanned downtime, and keep facilities running smoothly.

Practical tips for deployment

• Plan for clear access to the switch handle during routine maintenance to minimize downtime.
• Coordinate with your protection scheme to ensure the 3MFS400RT aligns with upstream fusing and downstream loads.
• Document the 400A rating and 120/240V capability in your electrical one-line drawings for future serviceability.