News

　　Medium-frequency induction furnace manufacturer: What causes an abnormal startup of a medium-frequency induction furnace?

　　The medium-frequency induction furnace manufacturer reminds everyone to use... Medium-frequency electric furnace After power-on, the device doesn't function properly, typically manifesting in the following ways: Below, our editor from the medium-frequency induction furnace manufacturer will introduce these issues to you.

　　1. Rectifier phase discrepancy: During operation, the fault manifests as abnormal noise and a significant output voltage that fails to reach its rated value. Additionally, the power cabinet starts emitting louder unusual noises. In such cases, we can reduce the product’s output voltage to around 200V and use an oscilloscope to observe the waveform of the rectifier’s output control voltage signal (the oscilloscope’s placement must be synchronized with the development of different power supplies). Under normal circumstances, the input and voltage-current waveforms should each exhibit six distinct waveform segments per cycle. However, in the case of phase discrepancy, due to the missing phase, only four waveform segments will appear, as shown in the figure. Typically, the root cause of this fault lies in one of the rectifier’s thyristors failing to receive the trigger pulse in time or failing to turn on properly. To diagnose this issue, first use an oscilloscope to check the gate pulses of all six rectifier thyristors. If gate pulses are present, after shutting down the system, use a multimeter set to the 200Ω range to measure the gate resistance of each thyristor. Replace any thyristors whose gate resistances are excessively high or whose gates appear blocked.

　　2. Operation of the third pin of the inverter: The fault display indicates an exceptionally high output current, even when the furnace is empty. During operation, the power cabinet produces an unusually loud noise. When you turn on the power knob, you’ll notice that the intermediate-frequency output voltage exceeds the normal value. Together with the oscillator, observe the voltage waveforms across the anodes and cathodes of the four inverters’ thyristors. If the three bridge arms are functioning properly, you’ll see that the waveforms of two adjacent thyristors are normal, while the waveforms of the other two adjacent thyristors show no waveform at all—instead, one of them exhibits a sine wave. The KK2 trigger is not working; both its anode and cathode waveforms are sine waves.

　　3. Induction Coil Failure: The induction coil is the load of the medium-frequency power supply and is made of square copper tubing with a wall thickness of 3–5 mm. Common failures include leakage current in the induction coil, which may lead to arcing between coil turns. Such issues must be promptly repaired by welding before operation can resume. If molten steel adheres to the induction coil, the resulting steel slag will become hot and red, potentially causing the copper tubing to burn through. Therefore, it is essential to clean the coil promptly.

　　That’s all for what the editor has explained. Medium-frequency electric furnace Does everyone understand the content about abnormal startup procedures? If you’d like to learn more about this topic, feel free to reach out to us. We hope the information shared by the editor has been helpful to you. Thank you for watching patiently, and we wish you all a happy life!

　　Shandong Kangda Electric Furnace Co., Ltd., abbreviated as Kangda Electric Furnace, is a manufacturer of medium-frequency electric furnaces and melting furnaces. It was formed through the merger of the Kangda Electric Furnace Maintenance Department, established in 1997, and Weifang Xinhua Machinery & Electrical Co., Ltd. The predecessor, the Kangda Electric Furnace Maintenance Department, specialized in the maintenance, energy-saving upgrades, repair of design defects, and troubleshooting of parallel and series electric furnaces, serving thousands of melting enterprises across China. With extensive experience in technological upgrades and engineering projects, the company has successfully analyzed and resolved numerous challenging faults for its clients. The company’s main products include steel-shell furnaces, series electric furnaces, induction heating furnaces, medium-frequency furnaces, closed-water-cooling systems, casting electric furnaces, medium-frequency induction furnaces, and medium-frequency equipment.