Inventory of drying methods for DC geared motors after getting damp
Date：2023-11-22 Author：XINDA MOTOR
When a DC geared motor is not used for a long time, it will be found that the insulation resistance of the geared motor windings will decrease with repeated use. Especially in the rainy season, the air humidity is high and the insulation value can even drop to zero. It should be dried at this time so that the insulation resistance and absorption rate reach the specified values. Here are some drying methods for everyone. Come and take a look.
1. Welding machine drying method
1. Before drying the AC welding machine, connect the moist terminals of the motor windings in series to the chassis and ground them to heat and dry the three groups of windings. In order to monitor the current changes during the drying process, an ammeter can be connected in series to observe whether the current reaches the rated current of the reduction motor. Using an AC welder to dry a DC reduction motor does not require disassembly and inspection, which reduces the workload. At the same time, when the power is on , the motor will use its own resistance to heat, so that the coil is heated evenly and the drying effect is better.
2. The dry operation wiring of DC welding machine is similar to that of AC, and the series ammeter should be a DC ammeter. It is convenient to use a DC welding machine to dry wet geared motors, and it can dry large and medium-sized DC geared motors and high-voltage geared motors for a long time. In this way, when the welding machine operates for a long time or with high current, its internal components will not be damaged by long-term high current operation, so it can be used for large and medium-sized reduction motors for a long time. When drying with these two methods, all contacts are required. The contact should be good and tight. The outlet of the welding machine should use special wires, and the cross-sectional size should meet the current carrying capacity of the output current of the welding machine. Pay attention to the cooling of the welding machine transformer and ensure that the insulation resistance of the DC reduction motor cannot be lower than 0.1M. Pay close attention to the temperature of the reduction motor winding and adjust the voltage and current in time.
2. External heat source heating method: First dismantle and inspect the
humid reduction motor , then put the reduction motor in and bake it with a high-power incandescent bulb or place the reduction motor in a drying room to dry. This method is simple to operate, safe and reliable, but it is only suitable for small reduction motors and is easy to disassemble and inspect. However, for large and medium-sized reduction motors that are not easy to disassemble and inspect, the workload is relatively large and the feasibility is also reduced. It should be noted that during the operation of this method, the light bulb or heat source should not be too close to the coil to avoid burning out the coil. The gear motor housing can be covered with canvas and other insulation items.
3. Excitation coil drying method
The excitation coil drying method is to wind the excitation coil around the stator core of the DC reduction motor, introduce alternating current to cause the stator to generate magnetic flux, and rely on its iron loss to dry the stator of the reduction motor.
Through the content explained in this article, we can have a general understanding of the drying method of DC geared motors after getting damp, which can be applied in actual operations. I hope that the content explained in this article is helpful to everyone and can bring practical significance to everyone.
XINDA