Square D QMB323TW - 100A, 240V, 3-Pole, Fusible, Switch

Meet the Square D QMB323TW, a 100A, 240V, 3-Pole Fusible Switch engineered for reliable on/off isolation and precise overcurrent protection in demanding industrial and commercial environments. This compact, maintainable switch from a trusted electrical systems heritage is built to keep critical equipment safe while simplifying control and maintenance tasks.

Key specifications

• Model: QMB323TW
• Amperage: 100A
• Voltage: 240V
• Poles: 3-Pole
• Fused: Fusible

Why this fusible switch matters

The QMB323TW delivers a dedicated, single-point solution for isolation and protection. Its fusible design provides integrated overcurrent protection, giving you a clear, reliable disconnect for safe maintenance and quick response to electrical faults. The 3-Pole configuration ensures complete circuit isolation, which is essential for safeguarding motors, panelboards, and branch circuits in space‑constrained installations.

Ideal use cases

• Motor disconnects in small to medium drive systems where space is at a premium
• Panelboard isolation to facilitate safe servicing and fault containment
• Branch circuit protection in compact distribution setups where a dedicated fusible switch is required

Who benefits

• Electrical contractors deploying dependable, ready-to-install protection in new builds or retrofit projects
• Facilities managers coordinating safe shutdowns and maintenance across commercial or industrial sites
• Plant engineers seeking a durable, compact solution that pairs protection with straightforward operation

What makes it stand out

Unlike larger, bulkier disconnects or passive isolators, the QMB323TW combines robust protection with a compact footprint, making it easier to fit into existing panels without compromising safety or accessibility. The fusible design is purpose-built for quick fault response and straightforward maintenance, helping reduce downtime and keep systems running smoothly in harsh environments.

Practical considerations

• Confirm that the installation voltage and current align with your circuit requirements (240V, 100A).
• Follow local electrical codes and standards when integrating the switch into panelboards or motor circuits.
• Plan for routine inspection of the fusible elements as part of preventive maintenance to ensure reliable protection.