Square D MHL36400 - 400 A, 3-Pole Circuit Breaker | AmpState

Engineered for dependable protection in demanding electrical panels, the Square D MHL36400 is a 400 A, 3-pole molded case circuit breaker designed to safeguard your branch circuits and equipment in panelboards and loadcenters. Built to fit snugly into OEM systems, this breaker delivers reliable performance where it matters most—everyday operation, critical loads, and downtime prevention.

• Space-efficient, molded-case design: Optimizes panel real estate without sacrificing protection, making it ideal for compact or crowded electrical spaces.
• Thermal-magnetic trip unit: Combines solid overload protection with fast short-circuit interruption for stable, repeatable protection across varying loads and fault conditions.
• 400 A current rating: Handles large feeders and higher-current branch circuits in commercial or light-industrial environments, enabling robust distribution without frequent trips.
• 3-pole configuration: Suitable for three-phase systems, ensuring coordinated protection across all phases and safer, more reliable operation.
• OEM compatibility: Specifically designed to integrate with matching Square D OEM loadcenters and panelboards, simplifying installation and ensuring proper trip coordination.
• Versatile applications: Well-suited for residential, commercial, and light-industrial settings where dependable overcurrent and short-circuit protection is essential.

Why this model stands out

Compared to breakers that rely on magnetic protection alone, the MHL36400’s thermal-magnetic design reduces nuisance trips while still delivering instantaneous response to short circuits. This means fewer interruptions for occupants and equipment, and more predictable maintenance cycles for facilities teams. Its compact form and compatibility with Square D panel systems make it a practical upgrade or replacement for aging panels requiring higher-capacity protection.

Practical use cases

• Upgrading a commercial panelboard to support higher-demand feeders without expanding the enclosure footprint
• Protecting large 3-phase distribution circuits in light-industrial spaces
• Replacing a failed breaker in a Square D loadcenter to restore reliable, code-compliant protection

Technical specifications

• Manufacturer: Square D
• Part Number: MHL36400
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 400 A
• Number of Poles: 3
• Application: Branch circuit overcurrent and short-circuit protection

Available from AmpState, this Square D MHL36400 400 A 3-pole breaker is a trusted choice for professionals seeking durable, compatible protection for panelboards and loadcenters in diverse applications.