The DC geared motor is not used for a long time. When i […]
The DC geared motor is not used for a long time. When it is re-enabled, it will find that the insulation resistance of the geared motor winding is reduced. Especially in the rainy season, the air humidity is high, and its insulation value will even decrease to zero. At this time, it should be dried. Let the insulation resistance and absorption ratio reach the specified value. Here are some ways to dry:
First, electric welding machine drying method
1. AC welding machine drying method Before the operation, the wiring heads of the damp geared motor windings are connected in series, and the casing is grounded, so that the three sets of windings can be heated and dried to monitor the current change during the drying process. Only the ammeter, observe whether the current reaches the rated current of the geared motor. Drying the DC gear motor with AC welding machine does not need to disassemble it, which reduces the workload. At the same time, the geared motor uses its own resistance to heat when the power is applied, so that the coil is evenly heated, and the drying effect is better.
2, DC welding machine drying method operation wiring and AC similar, the string current meter should be DC current meter. Drying the damp-reducing motor with a DC welding machine is easy to operate and can dry the large and medium-sized geared motors and high-voltage geared motors for a long time. In this way, when the electric welding machine is working for a long time or when working with a large current, the internal components are not damaged due to long-time high-current operation, so the large and medium-sized geared motors can be used for a long time. It is worth noting that when drying by these two methods, all the joints must be in good contact and fastened. The electric wire of the welding machine should use special wires, and the cross-sectional size should meet the current carrying capacity of the welding machine output current. Pay attention to the cooling of the welding machine's own transformer, and ensure that the insulation resistance of the geared motor cannot be lower than 0.1MΩ. Also pay close attention to the winding motor temperature and adjust the voltage and current in time.
Second, external heat source heating method
After the dehumidified DC geared motor is first disassembled, it is baked in a geared motor with a high-power incandescent bulb, or the geared motor is placed in a drying room for drying. This method is easy to operate, safe and reliable, but it is only suitable for small geared motors that are easy to remove. For large and medium-sized gears that are difficult to dismantle, the workload is relatively large, and the feasibility is also reduced. It should be noted that when the method is operated, the bulb or the heat source should not be too close to the coil to prevent the coil from being burned, and the cover of the reduction motor casing may be covered with a canvas or the like for heat preservation.
Third, the excitation coil drying method
The excitation coil drying method winds the excitation coil on the stator coil core of the reduction motor, and introduces alternating current to make the stator generate magnetic flux, and relies on the iron loss to dry the stator of the reduction motor.