Schneider Electric QOB390 Bolt On Circuit Breaker

The Schneider Electric Square D QOB390 is a yellow, three‑pole bolt‑on circuit breaker rated for 90 A at 240 V, designed for use in QOB/NQ panelboard installations. As a member of the QOB bolt‑on family, it provides thermal‑magnetic overcurrent protection with a 10 kA interrupting rating at 240 V and mounts to bolt‑on interiors rather than plug‑in bus systems. Its three‑pole configuration enables common‑trip protection across all phases, making it suitable for protecting three‑phase branch circuits in commercial or light‑industrial electrical distributions, including feeders to motors, HVAC equipment, and other 3‑phase loads in compatible panels. The QOB390 corresponds to the 90 A, 240 V, 10 kAIC class of Square D QO/QOB bolt‑on breakers and is designed for installation in panelboards that accept bolt‑on breakers, providing a reliable, field‑mountable protection solution where bolt‑on mounting is required.