The most common fault phenomenon of medium frequency furnace in use is that it cannot be started normally. The following lists the common causes and detection methods of failure to start:

1. Thyristor breakdown, measured by multimeter, the resistance is almost zero.

2. If the water-cooled cable is broken, the two ends can be stripped off and connected to the two ends of the cable. If it can be started, it indicates that the cable is broken. Pay attention not to pull up the power and avoid unnecessary danger caused by high current burning the wire.

3. If the medium frequency transformer is burnt out, measure the 1000V resistance, which should be about 70 Ω.

4. If output sintering, because the IF output line is too small, the power has lost heat energy.

5. Harmonic current resistance of current transformer is burnt out.

6. There is a problem with the inverter pulse transformer.

7. If the electric heating capacitor is burnt out, remove the copper bar and check it with a 1000V insulation ohmmeter or use a multimeter to check the charge and discharge.

8. When the melting furnace passes through the furnace, use a multimeter to measure the resistance between molten steel and induction coil.

9. If the intermediate frequency control board has parts breakdown and aging, replace the board.