Square D QMB367W – 800A, 600V, 3-Pole Fusible Panelboard Switch – QMB Series

The Square D QMB367W is a purpose-built 800 A, 600 V, 3-pole fusible panelboard switch designed to live inside QMB fusible panelboards. It delivers a reliable load disconnect paired with precise overcurrent protection, optimized for high-current distribution in industrial and commercial environments. When matched with the correct fuse class, this single device becomes the core protection and isolation point your panel needs, reducing wiring complexity and maintenance considerations.

Integrated protection and isolation

As a fusible panelboard switch, the QMB367W combines the disconnect function with overcurrent protection in a single, code-friendly package. This eliminates the need for separate protective devices in many panel configurations, simplifying installation and serviceability while maintaining clear, safe isolation for maintenance work.

Three-phase precision for demanding systems

The 3-pole design ensures balanced, reliable operation across three-phase feeders. This symmetry minimizes voltage imbalances and helps maintain stability in high-current distributions typical of data centers, manufacturing lines, and large commercial facilities.

High fault current capability

With a KAIC rating of 200 kA, this switch can safely interrupt substantial fault currents encountered in modern electrical installations. That means improved uptime and enhanced protection for downstream equipment, even in demanding power environments.

Designed for seamless QMB compatibility

Specifically engineered to fit Square D QMB fusible panelboards, the QMB367W ensures electrical coordination, straightforward wiring, and long-term serviceability. It also aligns with the broader Square D fuse families, supporting dependable spare parts availability and consistent performance over time.

Ideal applications

• Industrial facilities with high-current feeders requiring a single, reliable disconnect and protection point.
• Commercial buildings and data centers where three-phase distribution demands robust, code-compliant protection inside a fusible panelboard.
• Main feeder or branch feeder protection within QMB fusible panelboards to simplify design and reduce component counts.

How it works and installation considerations

Install the QMB367W by pairing it with the appropriate fuse class and the matching QMB fusible panelboard. Ensure wiring and bus connections are sized for 800 A at 600 V and that the three-phase configuration aligns with your system. This setup delivers clean fault clearing, safe servicing, and clear compliance with applicable electrical codes, while keeping maintenance streamlined and predictable.

Why choose the QMB367W

Opting for this model means selecting a purpose-built, high-current fusible solution backed by Schneider Electric’s engineering rigor and the reliability of the Square D QMB Series. It consolidates protection and isolation, lowers wiring complexity, and supports ongoing availability of compatible fuses and spare parts for years of dependable operation. If you’re elevating panel protection with a dedicated, high-current fusible switch, the QMB367W provides robust performance, dependable uptime, and a clear path to compliant, safe electrical distribution.