Eaton NS3-400-NA - 400A, 3-Pole, Disconnect Switch

The Eaton NS3-400-NA is a rugged, high-performance disconnect switch engineered for industrial and commercial environments where safe, reliable electrical isolation is non-negotiable. With a 400A rating across 3 poles, it delivers clean, dependable disconnection under load, helping maintenance teams execute lockout/tagout procedures with confidence and keeping downtime to a minimum.

What makes the NS3-400-NA stand out

• 400A, 3-Pole configuration ensures complete isolation of three-phase circuits, reducing the risk of arc flash and accidental re-energization during service work.
• Designed for lockout/tagout compatibility, enabling safe, compliant maintenance shutdowns.
• Rugged construction built to endure demanding industrial environments and provide long-term reliability.
• Compact enough for standard electrical rooms and panel enclosures, with straightforward installation and wiring.
• Dependable disconnection under load to prevent unexpected energization when equipment is being serviced.

Who benefits most

Facilities engineers, maintenance technicians, and electrical contractors working in manufacturing floors, data centers, processing plants, or commercial power rooms will find the NS3-400-NA to be an essential safety and reliability asset for service disconnects and routine shutdowns.

Practical use cases

• Main service disconnect for three-phase feeders powering motors, drives, and heavy equipment.
• Isolating sensitive loads during preventive maintenance without affecting upstream systems.
• Primary safety switch in switchgear rooms that supports lockout/tagout protocols.
• Dedicated isolation point for testing or commissioning new equipment.

Key specifications

• Amperage rating: 400A
• Number of poles: 3-Pole
• Product type: Disconnect Switch
• Brand: Eaton
• Model: NS3-400-NA

Care, use, and installation notes

Install in accordance with local electrical codes and the device’s enclosure requirements. Keep the switch clean and dry, inspect the operating mechanism periodically, and verify that lockout/tagout devices are compatible with the switch handle during maintenance planning. For best results, pair this disconnect with appropriately rated conductors and protective devices to maintain system safety and reliability over the life of your installation.