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When a medium-frequency induction furnace malfunctions, it can affect the efficiency of casting production. Therefore, identifying the root cause of the fault is something we should always be prepared to do. By looking beyond the surface phenomena to grasp the underlying essence, it becomes especially crucial to trace the source of the problem once a fault arises.
Intermediate-frequency furnace failure Phenomenon: The equipment is functioning normally, but the power output of the intermediate-frequency induction furnace cannot be increased.

Cause analysis: The fact that the equipment is functioning normally only indicates that all its components are intact. The inability to increase power suggests that the equipment’s parameters have not been adjusted appropriately. ，

The main reasons why the power output of medium-frequency furnace equipment cannot be increased are:
Methods for addressing the issue of insufficient power output in medium-frequency furnaces
1. The rectifier section is not properly adjusted; the rectifier tube is not fully conducting, and the DC voltage has not reached its rated value, thereby affecting power output.
2. If the intermediate-frequency voltage is set too high or too low, it will affect the power output.
3. Improper adjustment of the current and pressure setpoints results in low power output.
4. The furnace body is incompatible with the power supply, severely affecting power output.
5. If the compensation capacitors are configured in excess or insufficient quantities, neither optimal electrical efficiency nor optimal thermal efficiency can be achieved, meaning that the power output will not be economically optimal.
6. Excessive distributed inductance in the intermediate-frequency output circuit and excessive additional inductance in the resonant circuit also affect the maximum power output.
Another reason why the medium-frequency furnace cannot reach its full power output is that the thyristor-based medium-frequency induction furnace unit operates normally at low power.
When the power of the medium-frequency induction furnace increases, overcurrent or overvoltage protection is activated. In such cases, you can inspect and address the following components:
The first thing that needs to be checked is the main circuit of the medium-frequency furnace. Thyristor Is the component aged, resulting in a decrease in its current and voltage ratings? Is the thyristor’s RC snubber circuit experiencing poor contact, damage, or open circuits? Next, regarding the reactor, check whether the turn-to-turn insulation of the load inductor is intact. Also, verify that the cooling water passages are not blocked, the water temperature is not excessively high, and the water pressure is not too low. Finally, confirm whether the withstand voltage of the load compensation capacitors has declined.
Has the anti-interference performance of the medium-frequency induction furnace control system deteriorated, particularly in the thyristor triggering circuit? As the medium-frequency power increases, interference also intensifies, potentially causing false tripping of overcurrent or overvoltage protection. Is the firing angle advance of the inverter circuit too small? When the current rises, commutation may fail, triggering the overcurrent protection. Are the waveforms of the main circuit thyristors normal (is there phase loss in the rectifier circuit output, and is there phase loss in the inverter circuit output)?
After thoroughly checking the components we’ve mentioned above, we should be able to pinpoint the issue and quickly resolve any faults that may arise in the medium-frequency induction furnace, thereby improving production efficiency. If you encounter any other medium-frequency induction furnace problems that you’re unable to solve, please feel free to contact Mr. Li from Kanda Induction Furnace at 18365639009.