Dc motor controller in use, can appear sometimes cannot be started, is this why?
Below small make up for you answer.
Power loss: it could be a power switch didn't together, before the fuse fusing, contactor power control device failure, and so on and so forth.
And for the treatment of these conditions is the need to fuse level began to once upon a time, check the motor controller all the parts of the main circuit and control circuit conductors and devices, and then find out the reason and repair.
Motor controller failure: it could be a brush wear serious, stuck, spring pressure is not enough, and so on and so forth.
For the treatment of these conditions is to use a multimeter to check, and then find the breakpoint to repair.
Above is the cause of dc motor controller cannot be started, and handling.