Circuit breaker with individual gap adjustment at high and low settings of magnetic trip

A multiphase circuit breaker has a magnetic trip assembly which includes an adjusting bar slidable longitudinally to simultaneously adjust the bias applied by individual torsion springs to the rotatable armature of the magnetic trip assembly for each pole over a range of trip currents from a high setting to a low setting. Adjusting screws carried by the adjusting bar provide for adjustment of the gap between the armature and stationary magnetic structure independently at the high and low settings separately for each pole. An additional set of adjusting screws can be inserted in the adjusting bar to provide a single adjustment of the gap over the full range of spring bias settings.