Will a QOB40MW150 accept either QO tandem breakers or QOT tandem breakers?
QO load center
Selection of correct breakers
QOB40MW150 was merely a box number, not the load center number. It was associated with the load center catalog number QO30MW150, which would not accept QOT tandem circuit breakers. Although the QO tandems would physically fit, they could not legally be used since the QO30MW150 was a Class CTL load center.