Square D | LAB36400-BLACK | Circuit Breaker | 400A | 3-Pole | 600V

Meet the Square D LAB36400-BLACK circuit breaker—a rugged, high-current protection device built for demanding three-phase power systems. With a 400A rating and a 600V capacity, this unit safeguards your electrical distribution while supporting reliable, uninterrupted operation during faults.

Designed for maintenance, retrofit, and replacement where exact specifications matter, the LAB36400-BLACK ensures you can match existing panels and downstream equipment with confidence. The part number is the best reference for compatibility, so verify it before ordering to avoid mismatches in current, pole count, or voltage ratings.

Key specifications

• Amperage: 400 A
• Poles: 3-Pole
• Voltage: 600 V
• Part reference: LAB36400-BLACK — the best compatibility identifier

Why this Square D breaker stands out

For facilities relying on stable, scalable three-phase protection, this 3-pole model provides robust interruption capacity for up to 400 amps per circuit. It’s designed to fit Square D panel configurations that require a 600V, 3-pole solution, making it a practical option when replacing older units or retrofitting to accommodate upgraded loads.

Ideal use cases

• Maintenance and service upgrades of existing electrical distributions
• Retrofit projects where current ratings and pole count must align with legacy systems
• Replacement of worn or damaged breakers in high-demand, 3-phase circuits

Compatibility and installation notes

Before you order, confirm fit and ratings. The LAB36400-BLACK part number is the most reliable reference for matching your panel, bus, and trip characteristics. If you’re upgrading from a lower amperage or a different pole count, ensure the panel’s rating and enclosure clearances support a 400 A, 3-Pole, 600 V configuration.