Square D QOB3POLE20AMP Bolt-On Circuit Breaker

Square D QOB320 is a 3-pole, 20-amp bolt-on circuit breaker from the QOB family, designed for 120/240 VAC systems and intended for use in QOB bolt-on panelboards and compatible mounting bases. This thermal-magnetic device provides overcurrent protection for three-phase circuits, with a 10 kAIC interrupt rating at 240 VAC, and it mounts directly to the panel interior via bolts rather than clip-in mounting. The 20 A rating makes it suitable for feeders, motor loads, and branch circuits where moderate current protection is needed in commercial or light industrial distributions. As a bolt-on unit, installation requires mounting hardware to secure the breaker to the panel backplane, offering a robust alternative to plug-on breakers in installations that use bolt-on panels. The QOB320 aligns with Square D’s standard for QOB series compatibility, enabling consistent trip characteristics across the line when multiple poles are used in a system. In three-phase applications, this breaker protects all phases, helping prevent damage from overloads or short circuits while allowing straightforward replacement within compatible QOB panelboards and installations that rely on Three-Phase distribution.