Square D QMB3603 - High-Amp, 600V, 3-Pole Panelboard Switch / Switchboard Unit | AmpState

The Square D QMB3603 fusible panelboard switch delivers dependable load switching and robust overcurrent protection for lighting and distribution panelboards. Built for demanding commercial and industrial settings, this 3-pole unit is ready to coordinate with upstream protection and the correct fuse class, ensuring safe, reliable power control in a compact package.

• Three-pole, three-phase control — isolates and controls multi-wire panelboard feeds with clean, clear switching across all three phases.
• 600V class rating — engineered for higher-voltage distribution environments common in offices, facilities, and light-industrial spaces, delivering safe operation under demanding conditions.
• Fusible switching with protection — combines reliable switching with protective functionality when paired with appropriate upstream devices and fuse class, helping prevent damage from overloads.
• QMB series compatibility — seamless integration with Square D panelboards for consistent performance, straightforward retrofits, and smooth panel upgrades.
• Durable, field-ready construction — designed to withstand frequent operation in distribution boards and lighting panels, offering long-term reliability.
• Nameplate visibility and amperage coordination — verify the exact amperage on the unit’s nameplate to ensure proper coordination and protection in your system.

Ideal use cases

• Upgrading aging panelboards to restore modern protection and control in commercial buildings and industrial facilities.
• Configuring new electrical distributions that demand robust three-phase isolation and fast protection coordination.
• Retrofitting spaces that require clear switch control alongside dependable overcurrent protection.

Why choose the QMB3603 for your panel system

• The fusible switch provides dependable load switching while aligning with upstream protection—maintaining system integrity during faults or overloads.
• Optimizes panelboard layouts to deliver full three-phase control without sacrificing safety or clarity.
• Part of the Schneider Electric / Square D QMB family, synonymous with compatibility, availability, and long-term support.
• Emphasizes precise amperage coordination by design, helping you meet code requirements and avoid miscoordination in complex distributions.

When planning a panel upgrade or new installation, the QMB3603 from AmpState offers a dedicated fusible switching solution that aligns with reliability goals and capital budgets. It’s a practical, thoughtful choice for engineers and electricians who demand clear control, robust protection, and durable performance in lighting and distribution panels.