LJA36400U33XAASAYQ - 400 Amp Circuit Breaker

LJA36400U33XAASAYQ - 400 Amp Circuit Breaker

Engineered for high-demand electrical systems, the Square D LJA36400U33XAASAYQ delivers dependable protection and intelligent trip control in medium-voltage distribution environments. Rated for 600 VAC and equipped with a 25 kA interrupting capacity, this molded-case breaker keeps critical circuits safe from overloads and short circuits. The I-Line plug-in configuration simplifies installation and maintenance, while the MicroLogic 3.3S trip unit provides flexibility and precision for setting long-, short-, and instantaneous trip levels. With its balance of performance, reliability, and configurability, this breaker is well suited for industrial and commercial systems demanding high uptime.

Key Features and Benefits

• High fault-clearing capability: 25 kA rating at 600 VAC ensures strong protection during fault events.
• Adaptive trip settings: MicroLogic 3.3S unit supports LSI (long, short, instantaneous) adjustments to tailor protection to your load.
• Quick install & service: I-Line plug-in style simplifies mounting and replacement, reducing downtime.
• Sturdy, lasting build: Designed for consistent performance under demanding conditions.
• Integrated diagnostics (optional): Provides status feedback and trip logs, enabling easier troubleshooting.

Technical Specifications

• Amperage: 400 A
• Voltage Rating: 600 VAC
• Interrupting Capacity: 25 kA @ 600 VAC
• Poles: 3
• Trip Unit: MicroLogic 3.3S (LSI control)
• Mounting / Connection Style: I-Line plug-in
• Continuous Rating: 80 % (typical per catalog data)

Material Compliance and Certifications

• This breaker meets a comprehensive set of global safety and performance standards. It is UL-listed, CSA certified, NOM and IEC compliant, and carries the CE mark. Adherence to these certifications guarantees that it aligns with rigorous testing protocols and international regulatory requirements.

Where It Works Best

• Commercial power distribution panels — as a main or feeder breaker in 480/600 V service.
• Industrial plants and process facilities — to protect critical equipment and bus systems.
• Data centers and infrastructure environments — where high reliability and fast recovery are essential.
• HVAC, pumps, and motor loads — where selective trip coordination is needed.
• Upgrades in retrofit projects — it fits I-Line plug-in racks for easier integration.