... 55V AC, so as not to damage the module2.GND:DC power cathode3.A+,A-:Stepping motor one ... , or use axle flows fan dispels the heat, to make the module run reliably for a long time ... machinery is connected with driver , users are apt to connect the phase by mistake, thus would damage the ... of electrical machinery is a mistake . CW6060AC high quality stepper motor driver,2A-6A,Power input type:24V~55V AC