Troubleshooting of Medium Frequency Furnace This article introduces the faults and solutions of medium frequency furnace. 1. Fault phenomenon: large DC current, low DC voltage, and if the voltage, dull equipment sound, over-current protection. Analysis and treatment: the thyristor with one arm of the inverter bridge may be short-circuited or open-circuited, resulting in the operation of the three-arm inverter bridge. Use an oscilloscope to observe the voltage drop waveform of the thyristor on the four bridge arms of the inverter bridge. If the voltage drop waveform of the thyristor on one bridge arm is a line, the thyristor has been through; if it is a sine wave, the thyristor has not been through. Replace the through thyristor; find out the reason why the thyristor is not turned on. 2. Fault phenomenon: when the heavy load cold furnace is started, all electrical parameters and sounds are normal, but the power cannot be raised, and overcurrent protection. Analysis and