1. Electrode deviation or breakage: If the electrode is offset or broken, it will cause arc instability and cause instantaneous overcurrent. This is one of the common causes of OP protection.

2. Short circuit failure: If there is a metal conductor on the furnace lining or material surface, it may cause a short circuit between the coil and the furnace body, resulting in the activation of overcurrent protection.

3. Control system failure: The control system of the medium frequency electric furnace itself may also fail, such as damage to the control board, software abnormality, etc., resulting in the overcurrent protection being triggered incorrectly.

4. Parallel capacitor failure: Failure or aging of the parallel capacitor components of the medium frequency electric furnace may also cause overcurrent.

5. Power supply system failure: Voltage fluctuations or excessive harmonic content of the power supply system of the power grid may also trigger OP protection action.