Square D™ QO Series Miniature Circuit Breaker, 120 VAC, 40 A, 10 kA Interrupt, 2 Poles, Thermal Magnetic Trip

QO® (plug-on) and QOB (bolt-on) one-, two- and three-pole thermal-magnetic circuit breakers provide overcurrent protection and switching on ac and dc systems. Plug-on QO circuit breakers are for use in QO load centers, NQ and NQOD panelboards, OEM mounting bases, and Speed D™ switchboard distribution panels. Bolt-on QOB circuit breakers are for use in NQO and NQOD panelboards.QO and QOB circuit breakers have an overcenter, trip-free toggle mechanism with quick-make, quickbreak action and positive handle indication. The tripping mechanisms in two-and three-pole circuit breakers operate such that an overcurrent on any pole of the circuit breaker will cause all poles of the circuit breaker to open simultaneously. Each pole has an individual thermal-magnetic trip element calibrated for 40 deg C ambient temperature.