Square D QMB323TD - 100A, 240V, Fusible, Switch

Square D QMB323TD — a 100A, 240V fusible switch designed for reliable on/off isolation and precise overcurrent protection in demanding industrial and commercial environments. Its compact, maintainable form factor makes it a practical choice where space is at a premium, without sacrificing protection or performance.

The QMB323TD integrates a fuse in series with the load, delivering immediate fault isolation and controlled fault energy to safeguard motors, wiring, and downstream devices. This fusible design provides a clear, decisive disconnect point while supporting safe lockout/tagout procedures and straightforward fuse replacement in maintenance cycles.

Key specifications

• Model: QMB323TD
• Amperage: 100A
• Voltage: 240V
• Fusible: Fusible

Why this fusible switch matters

Choosing a fusible switch like the QMB323TD provides both isolation and protection in one compact device. It limits fault energy, helps prevent damage to upstream protection devices, and simplifies circuit coordination. This makes it an excellent solution for controlled shutdowns and protecting critical loads in environments where downtime is costly and reliability is essential.

Ideal use cases

• Motor disconnects in small to mid-size drives, pumps, or conveyors
• Panelboards requiring dedicated branch circuit protection
• Localized protection for critical circuits where quick, safe isolation is needed

Who benefits most

Electrical contractors, facilities engineers, maintenance teams, and plant operators who need a robust, maintainable, and space-efficient protection switch that combines isolation with built-in overcurrent protection.

Practical insights

For optimal performance, pair the QMB323TD with appropriately rated fuses and respect enclosure compatibility and replacement intervals. Its compact design supports streamlined wiring layouts and easier serviceability, helping you reduce installation time and downtime during maintenance.