Rehabilitating technologies and methods for large milling DC motor on site

The main problems faced by the repair of large motors are the difficulty of trouble finding, the unknown technical performance parameters of the repair materials, and the repair equipment and tools on-site cannot guarantee the implementation of the repair technology. Aimed the repair technology For the short circuit to ground fault of a large DC motor, a method of connecting bulb to find the fault of armature winding with equalizing voltage winding is introduced in the paper. Epoxy AB glue is used to varnish the motor in whole at room temperature, and ensuring the mechanical strengthen of coil conductor in groove of iron core, and commutating poles is circumvoluted by mica tape that is pressed by a special fixture to ensure the insulation performance of the poles. The test of applying 10 times of rated voltage to the main pole winding and measuring the voltage drop of each main pole winding is proved that repair method is feasible and can used to rehabilitate large DC motor on site.