... Installing categories:“Ⅲ”for breakers` main circuits, coils of under-voltage release and primary circuit of transformers;“Ⅱ”for other auxiliary circuits and ... poles three poles products) Type A:N-pole without overcurrent release unit, it has been connected all along, and does not act ... turn on or off Type B:N-pole without overcurrent release unit, it would act with other three poles.5. Production ...