Square D Q4L3400 - 400 A, 240 V, 3-Pole Circuit Breaker | AmpState

Meet the Square D Q4L3400, a 400 A, 240 V, 3‑pole molded‑case circuit breaker built to safeguard your panelboards and load centers from overcurrent and short‑circuit events. This unit brings reliable protection to large feeders while keeping your electrical space organized and optioned for future expansion.

Engineered for consistent protection in residential, commercial, and light industrial environments, the Q4L3400 features a thermal‑magnetic trip system that delivers stable, repeatable performance across varying loads and temperatures. The result is fewer nuisance trips and faster response to real faults, helping keep downtime and damage to a minimum.

• Space‑saving, molded‑case design minimizes footprint in crowded panels while delivering rugged reliability.
• 3‑pole configuration supports three‑phase circuits and ensures coordinated protection across all phases.
• Thermal‑magnetic trip unit provides dependable overload and fault protection with predictable trip characteristics.
• OEM‑compatible designed to pair with matching Square D loadcenters and panelboards for straightforward replacement and consistent performance.
• High‑capacity protection rated for 400 A at 240 V, ideal for main feeders and larger branch circuits in commercial or light industrial setups.

Technical snapshot

• Manufacturer: Square D
• Part number: Q4L3400
• Type: Thermal‑magnetic molded case circuit breaker
• Amperage rating: 400 A
• Voltage rating: 240 V
• Number of poles: 3
• Application: Branch circuit overcurrent and short‑circuit protection

Who benefits most from the Q4L3400? Electrical contractors, facility managers, and maintenance teams who need robust, high‑capacity protection in panelboards or load centers without sacrificing space or installation efficiency. It’s an ideal upgrade for aging panels, new commercial builds, or any system where reliable protection and OEM compatibility matter most.

Why choose this breaker over generic alternatives? It blends a compact, durable form factor with a precise thermal‑magnetic protection philosophy that’s proven in real‑world service. The 3‑pole design ensures complete phase coverage, while its compatibility with Square D OEM panels simplifies sourcing, stocking, and on‑site replacements—reducing downtime and compliance risk.

Practical tips for getting the most from your Q4L3400: ensure the panelboard is compatible with the Q4L3400 family, confirm the 240 V electrical system matches your installation, and verify the 3‑pole arrangement aligns with your feeder configuration. For best results, pair with a matching Square D loadcenter and follow standard installation practices for molded‑case breakers to ensure secure mounting and reliable electrical contact.