Siemens NR421 - 30A, 240V, Disconnect Switch, NEMA 3R

Meet the Siemens NR421 — a rugged 30A, 240V disconnect switch engineered for reliable on/off isolation and precise overcurrent protection in demanding industrial and commercial settings. Built with a NEMA 3R enclosure, this unit is ready to perform where weather, dust, and moisture are factors, so you can trust dependable operation day in and day out.

Designed for practical, maintenance-friendly service, the NR421 is a compact, fuse-protected disconnect switch that makes motor control, panelboard integration, and branch circuit protection straightforward. Its robust construction supports quick, safe disconnections for servicing, resets, or emergency shutdowns, while preserving long-term reliability in challenging environments.

• Electrical rating: 30A, 240V — suitable for a wide range of motor loads and branch circuits.
• Enclosure: NEMA 3R — weather-resistant for outdoor or protected indoor installations.
• Application focus: ideal for motor disconnects, panelboards, and branch circuit protection where a compact, maintainable fusible switch is required.
• Maintenance-oriented design: straightforward access for fuse replacement and periodic service, reducing downtime.

Why this matters for you

In environments where reliability and quick isolation are non-negotiable, the NR421 delivers. The combination of Siemens engineering and a 3R-rated enclosure means you can deploy this disconnect in exposed locations without compromising safety or performance. Its compact footprint helps fit into crowded panel spaces, while its maintainable fuse configuration simplifies routine servicing, minimizing downtime during repairs or upgrades.

Practical use cases

• Motor control centers and industrial drives where a clear, mandated disconnection point is required for safety and serviceability.
• Outdoor or semi-exposed electrical installations in manufacturing, facilities, or commercial buildings needing reliable branch circuit protection.
• Quick-pass protection for distribution panels, pump systems, conveyors, and small- to mid-size machinery fleets.

Technical snapshot

• NR421
• Amperage: 30A
• Voltage: 240V
• NEMA rating: 3R