Square D QO390VH 90A 3-Pole 390 V Circuit Breaker

Meet the Square D QO390VH 90A 3-Pole 390 V Circuit Breaker — a trusted, OEM solution built to protect three-phase power systems with precision and reliability. This model is identified by Part Number QO390VH and is designed to seamlessly integrate into Square D’s QO-series panels where robust, consistent performance matters.

• Current rating: 90 A — capable of handling sizable three-phase loads while providing dependable protection against overloads.
• Poles: 3 — disconnects all hot conductors in a three-phase circuit, enhancing safety and ensuring coordinated shutdown of power in fault conditions.
• Voltage rating: 390 V — suitable for distribution systems operating in the 380–400 V range, delivering reliable protection for mid-to-large scale applications.
• Series compatibility: Square D QO family — designed for plug-in compatibility with compatible QO panels and enclosures, enabling straightforward installation and dependable performance within established electrical infrastructure.
• Application scope: Ideal for commercial and light industrial environments where three‑phase power is used to run motors, pumps, conveyors, HVAC, and other equipment up to 390 V.

This model stands out for buyers seeking authentic Square D protection in a 3-pole, 90-amp form factor that fits standard QO panelboards. The QO390VH delivers predictable trip behavior and durable construction suitable for demanding installations, helping to minimize downtime and safeguard critical equipment.

Use cases and scenarios: Deploy in three-phase distribution feeders, motor control centers, or main distribution panels where a single protective device must reliably monitor multiple hot legs. Perfect for facilities upgrading from lower-capacity breakers or consolidating protection across a 3-phase circuit running up to 390 V.

Who this is for: Electrical professionals and facility managers who need a genuine Square D solution that matches existing QO panels and supports safe, compliant protection for 3-phase systems in commercial or light industrial settings.

Why choose this model: It pairs Square D’s proven engineering with a precise 90 A, 3-pole, 390 V specification, delivering consistent protection for mid-to-large loads while maintaining compatibility with the QO lineup for easy expansion or panel upgrades.