Square D | MJM36400 | Circuit Breaker | 400A | 3-Pole | 600V | Bolt-On

The Square D MJM36400 Circuit Breaker delivers robust overcurrent protection in a bolt-on, 3-pole design rated for 400 A and 600 V. Built for maintenance, retrofit, and replacement projects where exact specifications matter, this unit is identified by the part number MJM36400, making compatibility clear and straightforward for engineers and electricians.

• Amperage: 400 A
• Poles: 3-Pole
• Voltage rating: 600 V
• Mounting: Bolt-On
• Brand: Square D
• Best reference for compatibility: Part number MJM36400

Important compatibility notes: verify fit and ratings on your specific panel before ordering. The MJM36400 is the clearest compatibility reference, ensuring the bus interface and mounting method align with your enclosure’s design. This makes it especially suitable for legacy panels or systems where replacing like-for-like is critical to maintain protective coordination and service continuity.

Why this model stands out

• Designed to slot into panels that require a bolt-on, 3-pole configuration without modifying existing infrastructure.
• The MJM36400 designation is your go-to identifier to confirm exact specs and enclosure fit.
• With 400 A capacity and 600 V rating, it supports medium- to high-demand circuits common in commercial and light industrial environments.

Use cases and ideal applications

• Retrofit installations in existing industrial control panels where a bolt-on, 3-pole breaker is required to replace a failed unit or upgrade protection.
• Maintenance cycles in commercial facilities where maintaining precise part references simplifies ordering and ensures consistent protection profiles.
• Replacement in systems designed for 400 A service with 600 V circuits, where panel footprint and mounting style must remain unchanged.

Practical guidance: when planning a replacement or retrofit, start with the panel’s catalog number and the breaker’s part number. Match the amperage, voltage, pole count, and mounting type exactly, and use MJM36400 as the definitive reference to avoid mismatches. For best results, handle installation in accordance with your panel manufacturer’s instructions and local electrical codes, ensuring secure bolt-on mounting and proper electrical connections.