Square D QO340UK is a 40A, 3-pole miniature circuit breaker in the QO family, designed for 120/240V AC three‑phase service in industrial load centers. It provides overcurrent protection with a 10 kA short‑circuit interrupting capacity and is intended for use in Square D QO plug‑in panelboards. This 3P breaker is commonly used to protect three‑phase feeders and motors in commercial or light‑industrial electrical distributions.
