The electrical faults of the electric hammer mainly include open circuit, short circuit, grounding, and large spark of the rotor commutation ring.
The fault of the open circuit is mostly broken leather wire, among which the leather wire is most commonly broken at the root of the handle. This kind of broken wire has a characteristic, that is, connect the power wire of the electric hammer to the resistance gear of the multimeter, press the switch, and use the hand At the root of the active leather cable, the reading of the multimeter will change. In addition, the root of the plug is also easy to break, and there are many cases of broken switches. It is good to check the switch with a multimeter. Poor contact of the carbon brush can also cause an open circuit. Check There are two methods of carbon brush machine and poor contact:
The first observation is that the end face of the carbon brush is smooth and the contact is good, but the contact of the pockmarked surface is poor. Another way to check is to connect the test lead of the multimeter to the appearance end of the motor, and use two screwdrivers to press on the brush socket and the rotor at the same time. bad. The stator earring is blown, which can also cause the motor to open circuit.
The rotor is also open circuit sometimes, which is characterized by connecting the power cord to the multimeter and turning the rotor slowly, and the reading will change greatly. Grounding is generally caused by the stator and rotor wiping iron. The iron wiping needs to be replaced. The rotor, the other is dry caused by water or moisture. The large spark of the rotor is generally caused by the rotor failure and needs to be replaced. After the rotor is replaced, observe whether there is iron rubbing. If the iron is rubbed seriously, there will be a choking sound when it is turned on. If the iron is lightly rubbed for a long time, there will be a burnt smell and the current will also rise. The reasons for rubbing the iron are as follows. , The screws that fix the stator are loose, the bearing seat is too loose, the stator shell is deformed, and the bearing is damaged.
