Detection and Maintenance of Capacitors in Medium Frequency Furnace
When the medium frequency furnace fails and cannot be started, it is possible that the electrothermal capacitor connected in parallel with the load is broken down. The capacitors are generally installed on the capacitor rack in groups. Before inspecting, the group in which the broken-down capacitor is located shall be determined first
Disconnect the connection point between the bus bar and the main bus bar of each set of capacitors, and measure the resistance between the two bus bars of each group of capacitors. Under normal conditions, the resistance should be infinite. After confirming the faulty capacitor bank, disconnect the soft copper sheet of each electrothermal capacitor leading to the bus bar, and check one by one to find the broken capacitor.
Each electrothermal capacitor consists of four cores, the shell is one pole, and the other pole is led to the end cover through four insulators respectively. Generally, only one core will be broken down. Trip the lead on the insulator, the capacitor can continue to be used with a capacity of 3/4 of the original.
Another fault of the capacitor is oil leakage, which generally does not affect its use, but attention should be paid to fire prevention.