Splashing rainwater or moisture generated by condensation can invade the generator, especially when the generator is in intermittent operation. If the water or moisture cannot be discharged in time, the generator will be damp, and the transportation and construction process may also be damp. After the generator is damp or soaked, it must be dried in time. According to the capacity of the generator and the degree of moisture, the general treatment methods are as follow:
1. The generator should be cleaned or blown clean with compressed air before drying. If the drying method used must keep the rotor in operation, attention should be paid to general mechanical inspections such as the air gap between the stator and the rotor, the gap between the rotating parts, the bearing gap, and the lubrication of the oil circuit. Also pay attention to checking the bearing oil temperature and bearing vibration during operation.
2. The external heating method is suitable for drying all motor windings. It heats the stator by external heat sources such as incandescent lamps, (far) infrared lamps or electric furnaces. The motor is usually disassembled and the heat source is placed in the center of the stator, but do not directly touch the iron core, slot or coil to avoid burning. But the best method of heating is to use an electric drying oven with adjustable temperature and an electric drying room or steam drying room with air circulation ventilation equipment, which is most suitable for drying after the winding is dipped in paint.
3. Current drying method The current drying method is to pass the motor windings into low-voltage current with a certain connection method, and use the copper loss of the motor to heat itself. Its wiring has many forms, but regardless of any form of dry connection, the maximum current distributed by each phase winding should not exceed 50% or 60% of the original rated value; if DC is used, it can be slightly higher, which is the original rated value 60% of *80%. Since the specific conditions of various motors are not the same, the general required drying current should be based on the stator core reaching 70 to 80 kmh within 3^4h.
4. The eddy current drying method uses alternating magnetic flux to generate hysteresis and eddy current loss in the stator core to make the motor heat to the necessary temperature for drying, so it is also called the iron loss drying method. The magnetic flux in the iron core is generated by the exciting coil temporarily wound on the stator iron core and the outer shell. It is suitable for drying larger motors, and the advantage is that it consumes less power and is more economical.
Precautions when the motor is dry
1. The winding must be cleaned up before the motor is dry. If it is energized and dry, the housing must be grounded to prevent electric shock.
2. In order to prevent the heat dissipation of the motor, the motor should be covered for heat preservation during the drying process, but there should be a certain amount of ventilation to remove the moisture in the motor, especially the closed motor, and the end cover should be opened-the gap, so that the machine Moisture inside is easy to radiate.
3. During the drying process of the motor, use a thermometer or other temperature measuring devices to check the heating temperature to prevent damage to the motor due to overheating at a certain point.
4. When drying the motor, the heating temperature should be gradually increased, especially the humid motor, should be slowly heated to 50~60C, and maintained for 3 4h, and then heated to the maximum allowable temperature.
5. During the drying process, the winding temperature and motor insulation resistance should be measured regularly and recorded. It is recorded every 15 minutes at the beginning and every hour thereafter. Generally, after the drying starts, the insulation resistance will decrease due to the increase in temperature and moisture removal, but it will start to rise again later. When the insulation resistance is greater than the specified value and remains stable for 4 "5 hours, it indicates that the winding has been dried, and the drying process can be stopped.
The above are the treatment method of the generator damp or soaked by the Starlight Company. I believe that through today's study, you can accurately and timely take effective solutions when encountering the generator’s damp or dipping to reduce the impact to the lowest.
Starlight Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, welcome send email to email@example.com we will pay highly attention on your question.