Siemens NR423 100A 3P 240V Safety Switch, NEMA 3R, Fusible | AmpState

The Siemens NR423 is a robust 100 A, 3-pole, 240 V safety switch designed for reliable equipment disconnect and isolation right at the point of use. Built with retrofit workflows in mind, it preserves a consistent part number for smoother maintenance planning and faster spares ordering, so downtime is minimized and service crews stay in sync.

• 3-pole, 100 A, 240 V configuration suits medium-size, three-phase equipment loads while keeping a compact footprint for control rooms, switchgear, or outdoor installations.
• NEMA 3R enclosure provides weather-resistant protection suitable for both indoor and outdoor environments, guarding against rain and indirect exposure while keeping electrical connections secure.
• Fusible design integrates overcurrent protection directly into the disconnect, enabling coordinated protection for downstream equipment and simplifying fuse replacement during maintenance.
• Siemens reliability comes from a purpose-built safety switch engineered to meet industrial standards, ensuring consistent performance across environments and long service life.
• Smooth retrofit and procurement with a single, recognizable part number (NR423) helps maintain consistency across facilities and reduces compatibility questions during upgrades.

Why this NR423 safety switch matters in real-world setups

When you need an accessible, code-compliant equipment disconnect at the point of use, the NR423 delivers a straightforward solution that aligns with maintenance schedules and compliance checklists. Its fusible protection is ideal for systems where selective coordination and replaceable fuses are preferred, such as controlled HVAC loops, motor loads, and line-side disconnects for industrial equipment.

Ideal use cases

• Equipment disconnects for three-phase motors and driven loads
• Retrofit projects where maintaining a consistent part number simplifies stocking and service planning
• Outdoor or semi-enclosed installations requiring a weather-resistant enclosure
• Maintenance planning that benefits from straightforward fuse replacement and clear protection paths

Installation and compatibility notes

Designed to integrate into existing Siemens-based systems, the NR423 helps streamline upgrades and spares management. If you’re matching a part number or confirming compatibility for a retrofit, AmpState is available to assist with fitment and system alignment—ensuring your safety switch works seamlessly with current gear and wiring schemes.

Available from AmpState, the Siemens NR423 100 A 3P 240 V safety switch combines dependable protection, practical retrofit benefits, and a rugged NEMA 3R enclosure to keep critical equipment isolated and secure—not just during routine maintenance, but whenever you need a reliable point-of-use disconnect.