Square D D323N - 100A, 240V, 3-Pole, Fused Safety Switch

The Square D D323N is a purpose-built, industrial-grade Fused Safety Switch that delivers safe electrical isolation for demanding 3-phase systems. With a 100A rating and 240V operation, this 3-Pole disconnect is designed to provide dependable, under-load disconnection while supporting proper lockout/tagout procedures. It’s the trusted choice for facilities that require reliable isolation, consistent performance, and long-term durability in busy electrical rooms and equipment spaces.

Why the D323N stands out

• Three-pole fused design delivers robust isolation for 3-phase circuits, helping protect personnel and equipment during maintenance or troubleshooting.
• 100A continuous rating at 240V supports mid-to-large industrial loads such as motors, conveyors, and processing equipment.
• Lockout/tagout readiness facilitates safe servicing, ensuring circuits remain de-energized during maintenance.
• Under-load disconnection capability minimizes arcing and ensures a clean, controlled break in the circuit when switching.
• Durable, industry-ready construction designed to stand up to daily use in commercial and industrial environments.

Ideal applications and use cases

• Machine and line isolation in manufacturing floors where three-phase power drives equipment
• Service disconnects for motors, pumps, fans, and conveyors requiring reliable de-energization
• Maintenance shutoffs in electrical rooms, mezzanines, and equipment cabinets
• Safety-first control points where lockout/tagout procedures are standard practice

How this model fits into your electrical safety plan

The D323N is built to support a thorough safety workflow: isolate the circuit, apply lockout/tagout, verify non-energized status, perform maintenance, then restore power. By combining disconnection with fuse-based protection in a single unit, it reduces the risk of accidental energization and provides a clear point of reliability for electricians conducting routine servicing.

Technical snapshot

• 100A
• Voltage rating: 240V
• Poles: 3-Pole
• Product type: Fused Safety Switch
• Brand: Square D
• Model: D323N

Practical tips for installation and maintenance

• Plan the installation path to ensure easy access for lockout/tagout procedures and routine inspections.
• Verify circuit ratings align with the 100A, 240V specifications to ensure safe and reliable operation.
• Incorporate the switch into your control scheme as a dedicated service disconnect point for three-phase equipment.
• Regularly inspect the switching contacts and enclosure integrity as part of your preventive maintenance program.
• Follow your facility’s lockout/tagout policy when performing servicing to maintain compliance and personnel safety.