Square D QMB321TW - 30A, 240V, 3-Phase, Switch

Square D QMB321TW is a rugged 30A, 240V, 3‑phase switch engineered for reliable on/off isolation and overcurrent protection in demanding industrial and commercial environments.

With a compact, maintainable fusible design, the QMB321TW serves as a dedicated motor disconnect, a protective switch in panelboards, and a branch‑circuit protector where space and serviceability matter most.

Key capabilities

• 3‑phase, 240V operation: optimized for three‑phase motor circuits and distribution systems.
• 30A current rating: suitable for a wide range of drive motors and equipment without oversizing your protection.
• Compact, maintainable design: easy access for inspection, fuse replacement, and servicing in tight electrical rooms.
• Isolates circuits safely: provides a clear on/off break to permit safe maintenance and servicing.
• Built for industrial use: robust construction that stands up to the rigors of commercial and light industrial settings.

Ideal use cases

Install the QMB321TW as a motor disconnect right at the equipment, as a main or branch switching point in panelboards, or in any 3‑phase distribution path where reliable isolation and protection are required. It’s the practical choice for facilities that run 3‑phase motors, conveyors, pumps, and fans.

Why this matters

Rather than generic switches, the QMB321TW combines a proven Square D engineering pedigree with a compact form factor and clear, maintainable protection. By providing both isolation and overcurrent protection in a single, serviceable unit, it reduces downtime during maintenance and simplifies circuit protection planning for your motor control centers.

Installation and compatibility notes

Designed to integrate with standard 3‑phase distribution setups, the QMB321TW should be wired in accordance with local codes and your protective device scheme. Pair this fusible switch with appropriate fusing and supporting equipment to ensure complete motor circuit protection. Always verify the voltage, amperage, and phase requirements of your motors before installation.

Equip your facility with a dependable 3‑phase disconnect you can trust. The Square D QMB321TW delivers precise isolation, reliable protection, and straightforward maintenance for your critical motor loads.