Square D QMB326WT3 – 600A, 240V, 3-Pole Fusible Panelboard Switch – QMB Series (Class T fuse version)

Square D QMB326WT3 is a rugged, three-pole fusible panelboard switch engineered to live inside Schneider Electric’s QMB fusible panelboards. With a robust 600 A, 240 V rating and a Class T fuse version, this switch delivers decisive load disconnect and precise overcurrent protection when paired with the correct Class T fuses.

Why the QMB326WT3 stands out

Designed to integrate seamlessly into the QMB panelboard ecosystem, the QMB326WT3 provides:

• Three-pole, simultaneous isolation—ensures all phases open at once, preserving phase balance during maintenance or service work.
• 200 kAIC interrupting capacity—capable of safely interrupting high-fault currents common in demanding commercial or light industrial environments.
• Class T fusible protection—offers coordinated, code-compliant protection path for large feeders and motors within a panelboard assembly.
• Purpose-built fit for QMB panelboards—engineered to slot into existing QMB configurations without compromising protection coordination or accessibility.

Real-world applications and use cases

• Main or feeder disconnects in three-phase electrical distributions for commercial facilities and light industrial sites.
• Retrofits to add fusible protection inside established QMB panelboards, enabling selective coordination and enhanced maintenance safety.
• Feeder protection for large equipment or motor circuits that demand reliable isolation and prompt fault interruption.
• Installations where a dedicated Class T fuse path is preferred to maintain clear, code-aligned protection coordination.

Practical considerations for installation and operation

• Pair the QMB326WT3 with the correct Class T fuses specified for your QMB configuration to ensure proper protection coordination.
• Designed for three-phase 240 V systems—common in many commercial and industrial settings.
• Best installed by a qualified electrician as part of a complete QMB panelboard assembly to maintain proper protection coordination and safety compliance.
• Provides a clear, isolated point of protection for large feeders while keeping maintenance access straightforward within the QMB family.

Technical snapshot

• Amperage: 600 A
• Voltage: 240 V
• Poles: 3
• Interrupting Capacity (KAIC): 200
• Series: Schneider Electric / Square D, QMB
• Fuse Version: Class T (fusible panelboard switch)

Reliability and ecosystem fit

Engineered specifically for Schneider Electric’s QMB lineup, the QMB326WT3 delivers dependable performance with a maintenance-friendly form factor. It’s the decisive choice when you need a robust, three-phase fusible switch that integrates cleanly into a QMB panelboard and supports Class T fuse protection for coordinated, code-compliant protection of large feeders and motor circuits.