Failure Analysis of Electric Capacitor of Induction Melting Furnace
The capacitor of the induction melting furnace is ignited: There is a noise inside the machine when it is running, it is an insulation breakdown, and it should be replaced with a new one.
1. External ignition of the capacitor: When the machine is running, the external ignition will cause the capacitor shell to have poor insulation to the ground or the series capacitor connected in series and parallel with the booster is connected to the parallel capacitor shell.
2. If the cooling water is blocked, the heating and insulation will be damaged, which should be dealt with in time. Insulation inspection of electric heating capacitors. The insulation resistance of capacitors is divided into two-pole, multi-level insulation group and two-pole insulation resistance to the shell. Since the capacitor is composed of series and parallel capacitors, the insulation degradation of individual components will not cause The insulation resistance of the entire capacitor is reduced, so it is difficult to find defects by remotely measuring the insulation resistance between electrodes. Therefore, this test is generally not done, but only the insulation resistance measurement of the two-pole or multi-level enclosure. According to the different rated voltage, different voltmeters are used. Taking the rated voltage of 750v as an example, a 1000v shaker is used, and the capacitor should be discharged before shaking the side. When shaking the side, you should first shake the shaker to the specified speed. After the pointer is stable, connect the shaker to the two poles of the capacitor and continue to rotate the shaker. At the beginning, as the capacitor is charged, the pointer will drop, and then slowly rise until it stabilizes. The reading at this time is the inter-electrode resistance of the capacitor. Generally, 1000v should not be less than 1 megohm. After reading the number again, you should remove the line of the shaking table first, and then stop shaking. Otherwise, it is easy to burn the meter head due to the discharge of the capacitor. After the remote measurement, the capacitor should be discharged to avoid electric shock.